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Experimental HIV vaccine regimen is well-tolerated, elicits immune responses

Results from an early-stage clinical trial called APPROACH show that an investigational HIV vaccine regimen was well-tolerated and generated immune responses against HIV in healthy adults. The APPROACH findings, as well as results expected in late 2017 from another early-stage clinical trial called TRAVERSE, will form the basis of the decision whether to move forward with a larger trial in southern Africa to evaluate vaccine safety and efficacy among women at risk of acquiring HIV.

The APPROACH results will be presented July 24 at the 9th International AIDS Society Conference on HIV Science in Paris.

The experimental vaccine regimens evaluated in APPROACH are based on “mosaic” vaccines designed to induce immunological responses against a wide variety of HIV subtypes responsible for HIV infections globally. Different HIV subtypes, or clades, predominate in various geographic regions around the world. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, funded pre-clinical development of these vaccines. Together with other partners, NIAID supported the APPROACH trial, which is sponsored by Janssen Vaccines & Prevention B.V., part of the Janssen Pharmaceutical Companies of Johnson & Johnson. The manufacture and clinical development of the mosaic vaccines are led by Janssen.

“A safe and effective HIV vaccine would be a powerful tool to reduce new HIV infections worldwide and help bring about a durable end to the HIV/AIDS pandemic,” said NIAID Director Anthony S. Fauci, M.D. “By exploring multiple promising avenues of vaccine development research, we expand our opportunities to achieve these goals.”

APPROACH involved nearly 400 volunteers in the United States, Rwanda, Uganda, South Africa and Thailand who were randomly assigned to receive one of seven experimental vaccine regimens or a placebo. APPROACH found that different mosaic vaccine regimens were well-tolerated and capable of generating anti-HIV immune responses in healthy, HIV-negative adults. Notably, the vaccine regimen that was most protective in pre-clinical studies in animals elicited among the greatest immune responses in the study participants. However, further research will be needed because the ability to elicit anti-HIV immune responses does not necessarily indicate that a candidate vaccine regimen can prevent HIV acquisition.

According to the researchers, the findings from APPROACH, as well as from animal studies, support further evaluation of a lead candidate regimen in a clinical trial to assess its safety and efficacy. Plans for such a clinical trial to be conducted in southern Africa are in development, with projected enrollment of 2,600 healthy, HIV-negative women. Should the larger trial move forward, it is expected to begin enrollment in late 2017 or early 2018.

In APPROACH, study participants received four vaccinations over 48 weeks: two doses of an initial, or “prime,” vaccine, followed by two doses of a booster vaccine. The experimental regimens all incorporated the same vaccine components in the prime vaccination, known as Ad26.Mos.HIV. The vaccine uses a strain of common-cold virus (adenovirus serotype 26, or Ad26), engineered so that it does not cause illness, as a vector to deliver three mosaic antigens created from genes from many HIV variants. The booster vaccination included various combinations of the Ad26.Mos.HIV components or a different mosaic component, called MVA-Mosaic, and/or two different doses of clade C HIV gp140 envelope protein containing an aluminum adjuvant to boost immune responses.

The Ad26-based mosaic vaccines were initially developed by the laboratory of NIAID grantee Dan H. Barouch, M.D., Ph.D., and Janssen. In pre-clinical studies, regimens incorporating these mosaic vaccines protected monkeys against infection with an HIV-like virus called simian human immunodeficiency virus (SHIV). The most effective prime-boost regimen reduced the risk of infection per exposure to SHIV by 94 percent and resulted in 66 percent complete protection after six exposures. Researchers identified and characterized the vaccine-induced immune responses that correlated with this protection.

“The promising, early-stage results from the APPROACH study support further evaluation of these candidate vaccines to assess their ability to protect those at risk of acquiring HIV,” said Dr. Barouch, a principal investigator for APPROACH. He also is director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston and professor of medicine at Harvard Medical School.

Following the third vaccination, most APPROACH participants had developed antibody and cellular immune responses against HIV. The different boost vaccines altered the magnitude and character of these immune responses, with the regimen that showed greatest protection in monkey studies also eliciting among the greatest immune responses in humans. The anti-HIV immune responses increased after the fourth vaccination.

The researchers conclude that further evaluation of this approach would use a regimen comprising two Ad26 mosaic primes and two boosts with Ad26 mosaic and clade C gp140. The ongoing TRAVERSE trial is comparing Ad26-based regimens containing three mosaic antigens (trivalent) with Ad26-based regimens containing four mosaic antigens (tetravalent). Results from TRAVERSE are expected in late 2017.

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New Process May Lead To Vaccine For Schistosomiasis

Scientists at the Cornell and Ludwig Institute for Cancer Research have developed a way to produce a protein antigen that may be useful as vaccine for schistosomiasis — a parasitic disease that infects millions of people, mostly in tropical and subtropical climates according to new research in the journal Protein Expression and Purifaication, June 2017.

If clinical trials succeed, the vaccine may lead to a substantial decrease in the global number of schistosomiasis cases, which rank second only to malaria. The vaccine may have the added benefit of potentially reducing the incidence of bladder cancer.

Carl Batt, Cornell’s Liberty Hyde Bailey Professor in Food Science, and colleagues Leonardo Damasceno, Ph.D. ’08, of the Hertape Animal Health group in Brazil, and Gerd Ritter, of the Ludwig Institute for Cancer Research, established and refined the production of the antigen Sm14, using a microbial host. Sm14 holds promise to stimulate an immune response in humans, serving as a potential preventative vaccine for schistosomiasis.

“There is an association between parasitic infections and the occurrence of subsequent cancers. Schistosomiasis is not only a chronic disease but infected individuals have an enhanced propensity to get bladder cancer,” said Batt. “If you immunize people with an antigen that induces an immune response against schistosomiasis, there will likely be benefits not only in controlling the immediate infection but also a means to avoid bladder cancer.”

Schistosomiasis is caused by parasitic worms called Schistosoma mansoni, generally found in fresh water in lakes and rivers around the world, notably Africa and South America. The parasite is not found in the United States, according to the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention.

Both adults and children are susceptible to the disease. Schoolchildren — when they fish, swim or play in schistosoma-infested water — are particularly vulnerable to infection. WHO estimates that about 240 million people worldwide are infected and more than 66.5 million were treated for the disease in 2015.

“Ideally your immune system should rebuff these parasites, but they have the ability to suppress the human immune response. Thus, the worms avoid being killed by the immune system and they eventually target the human liver,” said Batt. “There is a very strong association between bladder cancer and a previous schistosomiasis infection.”

If the medical world aims to prevent schistosomiasis, then it makes sense to immunize people against the parasite, said Batt.

The second phase of clinical trials of the vaccine are underway in Brazil, conducted by Orygen Biotecnologia SA, and the Infectious Disease Research Institute, Seattle. The research, “Process Development for Production and Purification of the Schistosoma mansoni Sm14 Antigen,” was funded by the WHO through a collaboration between the Ludwig Institute for Cancer Research and Fiocruz, a Brazilian governmental scientific research agency.

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Immunotherapy with DNA vaccine shows promise for HPV-related head and neck cancer

A novel vaccine therapy can generate immune responses in patients with head and neck squamous cell carcinoma (HNSCCa), according to researchers at the Abramson Cancer Center of the University of Pennsylvania. The treatment specifically targets human papillomavirus (HPV), which is frequently associated with HNSCCa, to trigger the immune response. Researchers will present the results of their pilot study during the 2017 American Society of Clinical Oncology Annual Meeting in Chicago (Abstract #6073).

HNSCCa is a cancer that develops in the mucous membranes of the mouth, and throat. While smoking and tobacco use are known causes, the number of cases related to HPV infection – a sexually transmitted infection that is so common, the Centers for Disease Control says almost all sexually active adults will contract it at some point in their lifetimes – is on the rise. The CDC now estimates 70 percent of all throat cancers in the United States are HPV-related. Sixty percent are caused by the subtype known as HPV 16/18.

“This is the subtype we target with this new therapy, and we’re the only site in the country to demonstrate immune activation with this DNA based immunotherapeutic vaccine for HPV 16/18 associated head and neck cancer,” said the study’s lead author Charu Aggarwal, MD, MPH, an assistant professor of Hematology Oncology in the Perelman School of Medicine at the University of Pennsylvania.

The vaccine is delivered as an injection of antigens – which leads the immune system to start producing antibodies and activate immune cells. At the time of injection, physicians use a special device to deliver a pulse of electricity to the area, which stimulates the muscles and speeds the intake of the antigens. Aggarwal noted that this study represents a multidisciplinary approach involving the lab and the clinic.

“This is truly bench-to-bedside and shows the value of translational medicine within an academic medical center,” Aggarwal said.

Penn researchers treated 22 patients with the vaccine. All of the patients had already received therapy that was intended to be curative – either surgery or chemotherapy and radiation. When doctors followed up an average of 16 months later, 18 of those patients showed elevated T cell activity that was specific to HPV 16/18. All of the patients in the study are still alive, and none reported any serious side effects.

“The data show the therapy is targeted and specific, but also safe and well-tolerated,” Aggarwal said.

Because of the positive activity, Aggarwal says the next step is to try this therapy in patients with metastatic disease. A multi-site trial will open soon that combines the vaccine with PD-L1 inhibitors, which target a protein that weakens the body’s immune response by suppressing T-cell production.

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The “Geneva Signature” Measures the Safety and Efficiency of a Vaccine Against Ebola Virus Disease

An international team based at Geneva University Hospitals (HUG) and at the University of Geneva (UNIGE), Switzerland, has succeeded in defining a “signature” composed of a small number of inflammatory markers that can be monitored in order to understand how a promising anti-Ebola virus vaccine stimulates the immune system. The researchers inoculated 115 volunteers with either a high dose or a low dose of the rVSV-ZEBOV anti-Ebola vaccine, or with placebo. By analyzing the differences between the three groups, they found that it is sufficient to monitor only 5 substances that are naturally present in the blood in order to define immune responses to the vaccine. The “Geneva rVSV-ZEBOV signature” is published in a scientific paper, in Science Translational Medicine. It’s an easy-to-use equation adding up the concentrations of these 5 substances or markers, most of which are mediated by monocytes, a class of white blood cells known to be active in combatting Ebolavirus in infected individuals. The signature is also expected to inform investigations of safety and immunogenicity of other emerging vaccines.

The 2014–2015 Ebola epidemic affected several countries in West Africa, leading to the death of more than 11’000 people. Although this epidemic of Ebolavirus disease is over, there is no knowing if, when or where another may strike. It is therefore more important than ever to find a reliable vaccine against this deadly disease. Research on vaccines, which was ongoing during the epidemic in West Africa, is now yielding promising results.

Important progress in understanding the vaccine

In an article published on April 12, 2017, in Science Translational Medicine[1], a team from the HUG and the UNIGE, working in collaboration with researchers and clinicians in several other countries in Europe and Africa, has defined a formula that measures the reliability and efficiency of vaccines that might help prevent or limit future outbreaks.

The rVSV-ZEBOV vaccine (recombinant vesicular stomatitis virus–vectored Zaire Ebola vaccine) had already been shown to stimulate the immune system in human volunteers; and in a field trial in 2015 it successfully protected people who had been exposed to Ebola patients from contracting the disease themselves. Yet concerns had been raised during the Geneva trial regarding side effects. What the Geneva team has now published is a detailed examination of the blood plasma of 115 healthy volunteers from Geneva, some of whom received either a low-dose or a high dose of vaccine, while others received a placebo vaccine.

When a vaccine enters the bloodstream, dozens of inflammatory markers that are naturally present see their concentrations change over the next few days. The researchers investigated 15 of them (different varieties of chemokines or cytokines). They found that 1-3 days after the vaccine was administered, the concentration of 6 of these 15 markers had measurably increased. Using a statistical procedure known as principal components analysis, the Geneva team succeeded in producing a simple score that makes the activity of the vaccine much easier to monitor. This “signature” contains only 5 of the 6 markers most likely to change in the presence of the rVSV-ZEBOV vaccine: together, they account for over two-thirds (68%) of the variation in blood cytokine/chemokine activity.

The Geneva Signature found in Gabon

The signature was found to be stronger in volunteers who received the higher dose than in those who got the lower dose.

Importantly, the “Geneva signature” was applied to blood samples from a similar trial that took place in Lambaréné, Gabon, where healthy volunteers had also received the rVSV-ZEBOV vaccine. The same markers were elevated and correlated with side effects and later immunity in the same way.

The 5 markers in the signature are: monocyte attractant protein 1 (MCP-1), the interleukin-1 receptor antagonist (IL-1Ra), tumor necrosis factor (TNF-alpha), interleukin-10 and interleukin-6. Several of these are produced by monocytes or are known to interact with them, so the results imply that monocytes play a critical role in the efficacy and safety of the rVSV-ZEBOV vaccine.

In the case of many other vaccines, such as one recently developed against H1N1 influenza, the chemical markers mostly belong to another category of white blood cells: lymphocytes. Taken together, these signatures help understand how vaccines stimulate the immune system in very different ways to tackle various types of virus. This latest discovery therefore opens up encouraging perspectives for investigating the safety, efficacy and mechanisms of other emerging vaccines.

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Zika Virus Protein Mapped to Speed Search for Cure

A recently-published study shows how Indiana University scientists are speeding the path to new treatments for the Zika virus, an infectious disease linked to birth defects in infants in South and Central America and the United States.

Cheng Kao, a professor in the IU Bloomington College of Arts and Sciences‘ Department of Molecular and Cellular Biochemistry, has mapped a key protein that causes the virus to reproduce and spread.

“Mapping this protein provides us the ability to reproduce a key part of the Zika virus in a lab,” Kao said. “This means we can quickly analyze existing drugs and other compounds that can disrupt the spread of the virus. Drugs to target the Zika virus will almost certainly involve this protein.”

The World Health Organization reports that more than 1 million people in 52 countries and territories in the Americas have been infected with the Zika virus since 2015. The disease has also been confirmed to cause microcephaly in more than 2,700 infants born to women infected with the virus while pregnant. Symptoms include neurological disorders and a head that is significantly smaller than normal.

The virus is also transmissible through sexual activity and can trigger an autoimmune disease in adults called Guillain-Barre syndrome.

The IU-led study, conducted in collaboration with Texas A&M University, revealed the structure of the Zika virus protein NS5, which contains two enzymes needed for the virus to replicate and spread. The first enzyme reduces the body’s ability to mount an immune response against infection. The other enzyme helps “kick off” the replication process.

“We need to do everything we can to find effective drugs against the Zika virus, as changes in travel and climate have caused more tropical diseases to move into new parts of the globe,” said Kao, who has also spent 15 years studying the virus that causes hepatitis C.

“We’ve learned a lot of lessons about how to fight this class of virus through previous work on hepatitis C, as well as other work on the HIV/AIDS virus,” he added.

In addition, Kao said, the study showed that the Zika virus protein is similar in structure to proteins from viruses that cause dengue fever, West Nile virus, Japanese encephalitis virus and hepatitis C, which prompted the team to test several compounds that combat those diseases. The team also tested other compounds to disrupt the virus’s replication.

“Drugs approved to treat hepatitis C and compounds in development to treat other viral diseases are prime candidates to use against the Zika virus,” Kao said. “We’re continuing to work with industry partners to screen compounds for effectiveness against the NS5 protein.”

Other IU Bloomington authors on the study were Guanghui Yi and Yin-Chih Chuang in the Department of Molecular and Cellular Biochemistry and Robert C. Vaughan in the Department of Biology. Additional authors were Baoyu Zhao and Pingwei Li of Texas A&M University and Banumathi Sankaran at Lawrence Berkeley National Laboratory.

The method used to reproduce the virus protein in the lab is the subject of a U.S. patent application filed by the IU Research and Technology Corp.

The study appears in the journal Nature Communications. It was supported in part by the Johnson Center for Innovation and Translational Research at IU Bloomington.

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New Driver, Target in Advanced Mucosal Melanoma

Not all melanomas are created equal. While most melanomas appear on the skin as the result of sun exposure, a small subset of melanomas arise spontaneously from mucosal tissues. And while targeted treatments and immunotherapies have dramatically improved the prognosis for many patients with sun-associated melanomas, these treatments are ineffective in the mucosal form of the disease. A University of Colorado Cancer Center study published today in the journal Melanoma Research uses the unique resource of over 600 melanoma samples collected at the university to demonstrate, for the first time, novel mutations involved in mucosal melanoma, paving the way for therapies to treat this overlooked subtype.

“The treatment for melanoma has gotten pretty good in the past five years. But this is a different disease and the treatments that work in sun-caused melanoma don’t work in non-sun melanoma,” says William A. Robinson, MD, investigator at the CU Cancer Center and the Rella and Monroe Rifkin Endowed Chair of Medical Oncology at the CU School of Medicine. Robinson founded the melanoma tissue bank at CU, which has grown into a major national resource for scientists studying the disease.

The study compared whole-exome sequencing data from 19 patient samples of mucosal melanoma to 135 samples of sun-exposed melanoma. Importantly, mutations in the BRAF gene that are seen in more than half of advanced melanomas were absent in mucosal melanoma, explaining the ineffectiveness of BRAF-targeted treatments like vemurafenib. Instead, 32 percent of mucosal melanomas showed co-mutation of the genes KIT and NF1. Also, the paper reports mutations in the gene SF3B1 present in 37 percent of mucosal melanoma samples.

“We have seen SF3B1 mutation in chronic lymphocytic leukemia and in myeloid dysplastic disorders, and now we show its importance in mucosal melanoma,” says Aik Choon Tan, PhD, investigator at the CU Cancer Center and associate professor of Bioinformatics at the CU School of Medicine.

Because any sample of cancer cells is likely to contain thousands of mutations, advanced analytic tools are needed to distinguish harmless “passenger” mutations from the dangerous mutations driving the disease. For this purpose, the researchers used the computational tool IMPACT, developed in the Tan lab, to sort functional from missense mutations and to cross-reference candidate mutations with those previously reported in other cancer types.

“For the first time, this process demonstrates the functional role of SF3B1 in mucosal melanoma,” Robinson says.

The mechanics of SF3B1 are complex and only partially understood. Basically, the gene makes a molecule involved in preparing other genes for expression, helping to distinguish between regions of genes that should be manufactured and those that are silent genetic filler. Technically, SF3B1 sorts “exons” from “introns” – helping to cut and splice genetic code into the streamlined version that forms the plan for a protein. Unfortunately, if SF3B1 is mutated, this cutting and pasting can go awry in ways that introduce unintended bits of introns along with the intended bits of exons into the blueprint.

“Most often when material from introns is improperly included with exons, the result is nonsense proteins that go on to quickly degrade, meaning that cancer may use this strategy to downregulate the production of certain anti-cancer proteins,” Tan says. “On the other hand, an SF3B1 mutation could result in changes to the protein that are helpful to cancer cells, meaning that mucosal melanoma may be using this strategy to upregulate the production of proteins that can drive its growth.”

No matter if SF3B1 is nixing good proteins or boosting bad ones, the current project shows that stopping its action could benefit patients with mucosal melanoma. In fact, the researchers point out that phase 1 clinical trials are already underway for compounds targeting this gene in other cancers, meaning that the time needed to apply a similar strategy to mucosal melanoma could be dramatically shorter than if they had to start from scratch.

The group plans to continue exploring the mechanics of SF3B1 while also pushing forward with the preclinical work needed to form the rational basis for targeting this gene in patients with advanced mucosal melanoma.

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Penn Team Tracks Rare T Cells in Blood to Better Understand Annual Flu Vaccine

For most vaccines to work the body needs two cell types – B cells and T helper cells – to make antibodies. B cells are the antibody factories and the T helper cells refine the strength and accuracy of antibodies to home and attack their targets. A technique that identifies these helper immune cells could inform future vaccine design, especially for vulnerable populations.

Flu vaccines work by priming the immune system with purified proteins from the outer layer of killed flu viruses. An antibody is a protein that recognizes a unique pathogen molecule called an antigen that is specific for a particular strain. Antibodies bind to their targets with precision in the best of circumstances. In doing so, the antibody blocks a harmful microbe from replicating or marks it to be killed by other immune cells.

The level of antibodies in the blood tells immunologists how well a vaccine is working, specifically, how many antibodies are made and how strongly they disable microbes. The relatively scarce circulating T follicular helper cells, or cTfh for short, are key to antibody strength. Without Tfh, effective antibodies cannot be made, yet very little is known about cTfh cells in humans after vaccination.

Now, a team led by researchers from the Perelman School of Medicine at the University of Pennsylvania has found a way to identify the small population of cTfh present in the blood after an annual flu vaccine to monitor their contribution to antibody strength. They published their findings in Science Immunology this week. The studies, led by Ramin Herati, MD, an instructor of Infectious Disease, used high dimensional immune-cell profiling and specific genomic tests to identify and track these rare cells over time.

“The poor understanding of cTfh function is, in part, because these cells spend most of their time waiting in lymph nodes for the next infection, and not circulating in the blood,” said senior author E. John Wherry, PhD, a professor of Microbiology and director of the Institute of Immunology at Penn. “To get a handle on how well these cells are doing their job following vaccination, we have needed a way to measure their responses without gaining direct access to lymph nodes. Because of the central role of circulating T follicular helper cells in antibody development, new vaccine development strategies will benefit from a better understanding of the properties of these essential cells in the immune response.”

Molecular Bar Codes
Every T cell has a unique receptor on its outer surface. After receiving a vaccine, the result is one T cell with this unique bar code of sorts that replicates, making thousands of clones with identical copies of the same bar code. After vaccination this expansion of T cells dies down and a few clones remain behind. These memory cells wait it out in lymph nodes and other organs for the next time the infection or vaccine enters the body. These clones can then be called into action to protect the individual or help boost the vaccine immunity.

In the current study, the team was able to track circulating helper T cells because the unique bar code they possessed is specific to the strains used in an annual flu vaccine. Wherry and colleagues traced antibody production in 12 healthy subjects, aged 20 to 45 for three years from 2013 to 2105. The circulating subset of helper follicular T cells expressed different transcription factors and cytokines — Bcl-6, c-Maf, and IL-21 – compared to other T-cell subpopulations in the blood. The number of the cTfh cells sharply increased at seven days after a subject received a flu shot.

Repeated vaccination of the study participants brought back genetically identical clones of cTfh cells in successive years, indicating robust cTfh memory to the flu vaccine. These responses are a proxy for specific antibodies to the flu vaccine each year. In addition, these results measure the dynamics of vaccine-induced cTfh memory and recall over time, allowing investigators to monitor the key human-vaccine-induced cTfh responses and gain insights into why responses to flu vaccines are suboptimal in many people.

The ability to track these cTfh responses in the blood, instead of accessing lymph nodes in humans, allows for real-time monitoring of key cellular mechanisms involved in vaccination. Such knowledge should allow further optimization of vaccines for hard-to-treat diseases like the flu, but also HIV, and other infections in which inducing potent vaccines has been a challenge.

“These cTfh are a missing piece of being able to truly monitor and predict their ability to induce the desired magnitude and quality of immune memory, and therefore protection by vaccines,” Wherry said. The team next intends to look at elderly populations in which vaccines are not as effective and ask what role cTfh cell populations play in that part of the human population.

Co-authors are Alexander Muselman, Laura Vella, Bertram Bengsch, Kaela Parkhouse, Daniel Del Alcazar, Jonathan Kotzin, Susan A. Doyle, Pablo Tebas, Scott E. Hensley, Laura F. Su, and Kenneth E. Schmader.

 

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Cytotoxins Contribute to Virulence of Deadly Epidemic Bacterial Infections

Beginning in the mid-1980s, an epidemic of severe invasive infections caused by Streptococcus pyogenes (S. pyogenes), also known as group A streptococcus (GAS), occurred in the United States, Europe, and elsewhere. The general public became much more aware of these serious and sometimes fatal infections, commonly known as the “flesh-eating disease.” Potent cytotoxins produced by this human pathogen contribute to the infection. A new study in The American Journal of Pathology reports that the bacteria’s full virulence is dependent on the presence of two specific cytotoxins, NADase (SPN) and streptolysin O (SLO).

Bacteria produce cytotoxins that can cause cell death and result in infections of the deep fascia and other tissues, including necrotizing fasciitis. “Our research revealed that the most severe form of the disease requires two cytotoxins. If either one or both are missing, the infection is much less dangerous,” explained lead investigator James M. Musser, MD, PhD, chairman of the Department of Pathology and Genomic Medicine at Houston Methodist Research Institute (Houston, TX).

To evaluate how the toxins SPN and SLO act together, investigators used mice infected with genetically altered S. pyogenes strains that produced either, both, or neither of the toxins. They found that mutant strains lacking either SPN or SLO or both do not cause the most severe forms of necrotizing fasciitis, necrotizing myositis, bacteremia, and other soft tissue infections. Production of both toxins was required for full infection virulence.

Resistance to bacterial infections depends in part on innate immunity conferred by white blood cells, including polymorphonuclear leukocytes (primarily neutrophils). The researchers found evidence that infections with SPN- and SLO-deficient S. pyogenes could be controlled better because they were less likely to resist the bactericidal effects of human polymorphonuclear leukocytes.

According to the Centers for Disease Control and Prevention, approximately 700 to 1,100 cases of necrotizing fasciitis caused by group A streptococcus have occurred yearly since 2010. Although the disease primarily affects the young and old and those with underlying chronic conditions, it may also develop in healthy individuals. Transmission occurs person-to-person, many times through a break in the skin.

“We do not have a Group A strep vaccine that works right now,” commented Dr. Musser. “The information we gained from this research may help to develop more effective therapeutics, such as inhibitors of these two toxins, or even a vaccine.”

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GeoVax to Collaborate with Georgia State on Development of Hepatitis B Therapeutic Vaccine

The Georgia State University Research Foundation has entered into a research collaboration agreement with GeoVax Labs, Inc., a Georgia-based biotechnology company developing human vaccines, to advance development of a therapeutic vaccine for treatment of chronic Hepatitis B infections.

The Centers for Disease Control and Prevention estimates between 700,000 to 1.4 million people in the United States have chronic Hepatitis B virus infections, with an estimated 20,000 new infections every year.

The research collaboration will include the design, construction and characterization of multiple vaccine candidates by combining the preS VLP technology from Georgia State and GeoVax’s MVA-VLP vaccine platform. Unique VLP design and functional assays developed by Dr. Ming Luo, professor in the Department of Chemistry at Georgia State, and performed in collaboration with Peking University Shenzhen Graduate School, will provide key information on vaccine effectiveness.

“My team’s efforts continue to unveil the molecular mechanism of immune responses to HBV infection and we are excited to partner with GeoVax to further the development of a Hepatitis B therapeutic vaccine,” said Dr. Luo. “Globally, chronic Hepatitis B affects more than 240 million people and contributes to nearly 686,000 deaths worldwide each year. By joining forces with GeoVax, we will apply our highly complementary sets of expertise in an effort to address the problem.”

The vaccine will be based upon generating the preS VLP using the GeoVax’s novel MVA-VLP vector platform, which has been proven safe in multiple human clinical trials of the company’s preventive HIV vaccine. This platform is also being used to develop preventive vaccines against Zika virus and hemorrhagic fever viruses, such as Ebola, Sudan, Marburg and Lassa.

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Researchers Find Key Genetic Driver for Rare Type of Triple-Negative Breast Cancer

Researchers find key genetic driver for rare type of triple-negative breast cancer

New mouse model leads to surprising discovery that sheds light on metaplastic breast cancer

For more than a decade, Celina Kleer, M.D., has been studying how a poorly understood protein called CCN6 affects breast cancer. To learn more about its role in breast cancer development, Kleer’s lab designed a special mouse model – which led to something unexpected.

They deleted CCN6 from the mammary gland in the mice. This type of model allows researchers to study effects specific to the loss of the protein. As Kleer and her team checked in at different ages, they found delayed development and mammary glands that did not develop properly.

“After a year, the mice started to form mammary gland tumors. These tumors looked identical to human metaplastic breast cancer, with the same characteristics. That was very exciting,” says Kleer, Harold A. Oberman Collegiate Professor of Pathology and director of the Breast Pathology Program at the University of Michigan Comprehensive Cancer Center.

Metaplastic breast cancer is a very rare and aggressive subtype of triple-negative breast cancer – a type considered rare and aggressive of its own. Up to 20 percent of all breast cancers are triple-negative. Only 1 percent are metaplastic.

“Metaplastic breast cancers are challenging to diagnose and treat. In part, the difficulties stem from the lack of mouse models to study this disease,” Kleer says.

So not only did Kleer gain a better understanding of CCN6, but her lab’s findings open the door to a better understanding of this very challenging subtype of breast cancer. The study is published in Oncogene.

“Our hypothesis, based on years of experiments in our lab, was that knocking out this gene would induce breast cancer. But we didn’t know if knocking out CCN6 would be enough to unleash tumors, and if so, when, or what kind,” Kleer says. “Now we have a new mouse model, and a new way of studying metaplastic carcinomas, for which there’s no other model.”

One of the hallmarks of metaplastic breast cancer is that the cells are more mesenchymal, a cell state that enables them to move and invade. Likewise, researchers saw this in their mouse model: knocking down CCN6 induced the process known as the epithelial to mesenchymal transition.

“This process is hard to see in tumors under a microscope. It’s exciting that we see this in the mouse model as well as in patient samples and cell lines,” Kleer says.

The researchers looked at the tumors developed by mice in their new model and identified several potential genes to target with therapeutics. Some of the options, such as p38, already have antibodies or inhibitors against them.

The team’s next steps will be to test these potential therapeutics in the lab, in combination with existing chemotherapies. They will also use the mouse model to gain a better understanding of metaplastic breast cancer and discover new genes that play a role it its development.

“Understanding the disease may lead us to better ways to attack it,” Kleer says. “For patients with metaplastic breast cancer, it doesn’t matter that it’s rare. They want – and they deserve – better treatments.”

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Engineers design a new weapon against bacteria

Over the past few decades, many bacteria have become resistant to existing antibiotics, and few new drugs have emerged. A recent study from a U.K. commission on antimicrobial resistance estimated that by 2050, antibiotic-resistant bacterial infections will kill 10 million people per year, if no new drugs are developed.

To help rebuild the arsenal against infectious diseases, many scientists are turning toward naturally occurring proteins known as antimicrobial peptides, which can kill not only bacteria but other microbes such as viruses and fungi. A team of researchers at MIT, the University of Brasilia, and the University of British Columbia has now engineered an antimicrobial peptide that can destroy many types of bacteria, including some that are resistant to most antibiotics.

“One of our main goals is to provide solutions to try to combat antibiotic resistance,” says MIT postdoc Cesar de la Fuente. “This peptide is exciting in the sense that it provides a new alternative for treating these infections, which are predicted to kill more people annually than any other cause of death in our society, including cancer.”

De la Fuente is the corresponding author of the new study, and one of its lead authors along with Osmar Silva, a postdoc at the University of Brasilia, and Evan Haney, a postdoc at the University of British Columbia. Timothy Lu, an MIT associate professor of electrical engineering and computer science, and of biological engineering, is also an author of the paper, which appears in the Nov. 2 issue of Scientific Reports.

Improving on nature

Antimicrobial peptides, produced by all living organisms as part of their immune defenses, kill microbes in several different ways. First, they poke holes in the invaders’ cell membranes. Once inside, they can disrupt several cellular targets, including DNA, RNA, and proteins.

These peptides also have another critical ability that sets them apart from traditional antibiotics: They can recruit the host’s immune system, summoning cells called leukocytes that secrete chemicals that help kill the invading microbes.

Scientists have been working for several years to try to adapt these peptides as alternatives to antibiotics, as bacteria become resistant to existing drugs. Naturally occurring peptides can be composed of 20 different amino acids, so there is a great deal of possible variation in their sequences.

“You can tailor their sequences in such a way that you can tune them for specific functions,” de la Fuente says. “We have the computational power to try to generate therapeutics that can make it to the clinic and have an impact on society.”

In this study, the researchers began with a naturally occurring antimicrobial peptide called clavanin-A, which was originally isolated from a marine animal known as a tunicate. The original form of the peptide kills many types of bacteria, but the researchers decided to try to engineer it to make it even more effective.

Antimicrobial peptides have a positively charged region that allows them to poke through bacterial cell membranes, and a hydrophobic stretch that enables interaction with and translocation into membranes. The researchers decided to add a sequence of five amino acids that would make the peptides even more hydrophobic, in hopes that it would improve their killing ability.

This new peptide, which they called clavanin-MO, was very potent against many bacterial strains. In tests in mice, the researchers found that it could kill strains of Escherichia coli and Staphylococcus aureus that are resistant to most antibiotics.

Suppressing sepsis

Another key advantage of these peptides is that while they recruit immune cells to combat the infection, they also suppress the overactive inflammatory response that can cause sepsis, a life threatening condition.

“In this single molecule, you have a synthetic peptide that can kill microbes — both susceptible and drug-resistant — and at the same time can act as an anti-inflammatory mediator and enhance protective immunity,” de la Fuente says.

The researchers also found that these peptides can destroy certain biofilms, which are thin layers of bacterial cells that form on surfaces. That raises the possibility of using them to treat infections caused by biofilms, such as the Pseudomonas aeruginosa infections that often affect the lungs of cystic fibrosis patients. Or, they could be embedded into surfaces such as tabletops to make them resistant to microbial growth.

Other possible applications for these peptides include antimicrobial coatings for catheters, or ointments that could be used to treat skin infections caused by Staphylococcus aureus or other bacteria.

If these peptides are developed for therapeutic use, the researchers anticipate that they could be used either in stand-alone therapy or together with traditional antibiotics, which would make it more difficult for bacteria to evolve drug resistance. The researchers are now investigating what makes the engineered peptides more effective than the naturally occurring ones, with hopes of making them even better.

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Large Integrated Health Outcomes Study Reveals Shifting Epidemiology In Drug-Resistant Organisms

A first-of-its-kind study of 900,000 hospital admissions from an integrated health system has yielded insights into shifts in the epidemiology of multi-drug resistant organisms (MDROs) in the community.

New research, funded by OpGen (NASDAQ: OPGN) and conducted by Intermountain Healthcare and Enterprise Analysis Corporation (EAC), found that Methicillin Resistant Staphylococcus aureus (MRSA), Clostridium difficile (C. difficile) and ESBL harboring Gram-negative rods were the most common organisms treated by the Intermountain Healthcare system over an eight-year period between January 1, 2008 and December 31, 2015.

The study examined data from Intermountain Healthcare over an eight-year period to characterize the trends occurring in C. difficile and MDROs. The abstracted electronic data was pulled from patients seen at Intermountain’s 22 hospitals and affiliated clinics who had clinical cultures positive for antibiotic resistant Gram-positive or Gram-negative bacteria and/or laboratory tests positive for toxigenic C. difficile.

The researchers discovered that resistant organisms were found in 1.4 percent of the 900,000 hospital admissions during the study period with most originating from the ambulatory setting. Additionally, researchers found that a 222% increase was observed in the prevalence of C. difficile as well as a 322% increase in ESBL positive organisms. The good news is that the prevalence of MRSA decreased by 32%.

The study measured both the prevalence of infections, as well as impacts on patient care. Economic data are still being analyzed and will be revealed in a future presentation.

Results from the study were presented on Thursday, Oct. 27 at 1:30 p.m., EDT, in the Poster Hall at IDWeek 2016 in New Orleans by Bert Lopansri, M.D., lead author of the study at Intermountain Medical Center, the flagship hospital of Intermountain Healthcare.

Highlights of the study:

• Of the 900,000 hospital admissions during the study period, 12,905 (1.4%) were from patients positive for an MDRO and/or C. difficile.
• While MRSA continues to be the most common MDRO, rates have declined.
• MRSA, ESBL and CRE forms of E. coli were less frequently acquired in the hospital while VRE, multi-drug resistant Pseudomonas, and other CRE’s were more frequently encountered in a healthcare setting.
• 70% of all MDROs and C. difficile cases originated from an ambulatory setting.
• While all-cause, in hospital mortality was relatively low (7%), significantly more patients with MDRO require continued medical care in some capacity.

“For the last 10 to 15 years, the number of antibiotic-resistant bacteria continues to increase. We wanted to turn on the lights and look at all the different types of antibiotic-resistant bacteria that have been highlighted as serious and urgent threats by the Centers for Disease Control to see what the landscape looks like in our system,” said Dr. Lopansri, Chief of the Infectious Diseases Division at Intermountain Medical Center. “Although MRSA still poses the greatest challenge, the rise in ESBLs is a major concern and mirrors findings reported at other centers in the U.S. One concern with ESBLs is that the most common antibiotic used to treat them are carbapenems, known as ‘last-resort’ antibiotics.”

“Our support for a study of this magnitude provides a benchmark to hospitals and health systems on what could be lurking in their facilities as we seek to validate the health and economic impact of our rapid MDRO products and services to improve infection control,” said Evan Jones, Chairman and CEO of OpGen. “The next step in this collaboration will revolve around leveraging our technologies to guide rapid clinical decisions with a goal of reducing the spread of these infections and improving health outcomes.”

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Scientists Uncover Why Hepatitis C Virus Vaccine Has Been Difficult To Make

Researchers have been trying for decades to develop a vaccine against the globally endemic hepatitis C virus (HCV). Now scientists at The Scripps Research Institute (TSRI) have discovered one reason why success has so far been elusive.

Using a sophisticated array of techniques for mapping tiny molecular structures, the TSRI scientists analyzed a lab-made version of a key viral protein, which has been employed in some candidate HCV vaccines to induce the body’s antibody response to the virus. The researchers found that the part of this protein meant as the prime target of the vaccine is surprisingly flexible. Presenting a wide variety of shapes to the immune system, it thus likely elicits a wide variety of antibodies, most of which cannot block viral infection.

“Because of that flexibility, using this particular protein in HCV vaccines may not be the best way to go,” said co-senior author TSRI Associate Professor Mansun Law.

“We may want to engineer a version that is less flexible to get a better neutralizing response to the key target site and not so many off-target responses,” said co-senior author Ian A. Wilson, TSRI’s Hansen Professor of Structural Biology and a member of the Skaggs Institute for Chemical Biology at TSRI.

The report, published online ahead of print by the Proceedings of the National Academy of Sciences the week of October 24, 2016, is likely to lead to new and better HCV vaccine designs.

A Great Need

A working vaccine against this liver-infecting virus is needed desperately. HCV infection continues to be a global pandemic, affecting an estimated 130 to 150 million people worldwide and causing about 700,000 deaths annually from liver diseases including cancer. Although powerful antiviral drugs have been developed recently against HCV, their extremely high costs are far beyond the reach of the vast majority of people living with HCV infection. Moreover, antiviral treatment usually comes too late to prevent liver damage; HCV infection is notorious for its ability to smolder silently within, producing no obvious symptoms until decades have passed.

The Law and Wilson laboratories have been working together in recent years to study HCV’s structure for clues to successful vaccine design. In 2013, for example, the team successfully mapped the atomic structure of the viral envelope protein E2, including the site where it binds to surface receptors on liver cells.

Because this receptor-binding site on E2 is crucial to HCV’s ability to infect its hosts, it has an amino-acid sequence that is relatively invariant from strain to strain. The receptor-binding site is also relatively accessible to antibodies, and indeed many of the antibodies that have been found to neutralize a broad set of HCV strains do so by targeting this site.

For all these reasons, HCV’s receptor-binding site has been considered an excellent target for a vaccine. But although candidate HCV vaccines mimicking the E2 protein have elicited high levels of antibodies against the receptor-binding site, these antibody responses—in both animal models and human clinical trials—have not been very effective at preventing HCV infection of liver cells in laboratory assays.

Enormous Flexibility

To understand why, the Law and Wilson laboratories teamed up with TSRI Associate Professor Andrew Ward and used electron microscopy and several other advanced structural analysis tools to take a closer look at HCV’s E2 protein, in particular the dynamics of its receptor binding site. Their investigations focused on the “recombinant” form of the E2 protein, produced in the lab and therefore isolated from the rest of the virus. Recombinant E2 is a prime candidate for HCV vaccine design and is much easier to purify and study than E2 from whole virus particles.

One finding was that recombinant E2, probably due to its many strong disulfide bonds, has great structural stability, with an unusually high melting point of 85°C. However, the TSRI scientists also found evidence that, within this highly buttressed construction, the receptor binding site portion is extraordinarily loose and flexible in the recombinant protein.

“It adopts a very wide range of conformations,” said study first author Leopold Kong, of TSRI at the time of the study, now at the National Institutes of Health.

Prior studies have shown that HCV’s receptor binding site adopts a narrow range of conformations (shapes) when bound by virus-neutralizing antibodies. A vaccine that elicited high levels of antibodies against only these key conformations would in principle provide effective protection. But this study suggests that the E2 protein used in candidate vaccines displays far too many other binding-site conformations—and thus elicits antibodies that mostly do nothing to stop the actual virus.

Law and Wilson and their colleagues plan to follow up by studying E2 and its receptor binding site as they are presented on the surface of the actual virus. They also plan to design a new version of E2 or even an entirely different scaffold protein, on which the receptor binding site is stabilized in conformations that will elicit virus-neutralizing antibodies.

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Cytomegalovirus Infection Relies On Human RNA-Binding Protein

Viruses hijack the molecular machinery in human cells to survive and replicate, often damaging those host cells in the process. Researchers at the University of California San Diego School of Medicine discovered that, for cytomegalovirus (CMV), this process relies on a human protein called CPEB1. The study, published October 24 inNature Structural and Molecular Biology, provides a potential new target for the development of CMV therapies.

“We found that CPEB1, one of a family of hundreds of RNA-binding proteins in the human genome, is important for establishing productive cytomegalovirus infections,” said senior author Gene Yeo, PhD, professor of cellular and molecular medicine at UC San Diego School of Medicine.

CMV is a virus that infects more than half of all adults by age 40, and stays for life. Most infected people are not aware that they have CMV because it rarely causes symptoms. However, CMV can cause serious health problems for people with compromised immune systems, or babies infected with the virus before birth. There are currently no treatments or vaccines for CMV.

In human cells, RNA is the genetic material that carries instructions from the DNA in a cell’s nucleus out to the cytoplasm, where molecular machinery uses those instructions to build proteins. CPEB1 is a human protein that normally binds RNAs that are destined to be translated into proteins.

Yeo’s team discovered that CPEB1 levels increase dramatically in human cells infected by CMV. Using genomics technologies, the researchers also found that increased CPEB1 levels in CMV-infected cells leads to abnormal processing of RNAs encoding thousands of human genes. In addition, they were surprised to find that CPEB1 was necessary for proper processing of viral RNAs. Without the host CPEB1 protein, viral RNA did not mature properly and the virus was weakened.

CMV-infected human cells undergo abnormal changes and produce more virus, which ultimately infects other cells. In collaboration with Deborah Spector, PhD, Distinguished Professor at UC San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, the team went on to show that suppressing CPEB1 levels during CMV infection reversed these harmful cellular changes and reduced viral production tenfold.

“CPEB1 was previously shown to play a role in neuronal development and function, but this involvement in active viral infections is unexpected,” said first author Ranjan Batra, PhD, a postdoctoral fellow in Yeo’s lab. “This discovery has important implications for many viral infections.”

Yeo said the next steps are to determine the therapeutic value of inhibiting CPEB1 in CMV infections and identify other RNA-binding proteins that may be important in other viral infections.

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Neurodevelopmental Model Of Zika May Provide Rapid Answers

A newly published study from researchers working in collaboration with the Regenerative Bioscience Center at the University of Georgia demonstrates fetal death and brain damage in early chick embryos similar to microcephaly—a rare birth defect linked to the Zika virus, now alarming health experts worldwide.

The team, led by Forrest Goodfellow, a graduate student in the UGA College of Agricultural and Environmental Sciences, developed a neurodevelopmental chick model that could mimic the effects of Zika on the first trimester. Historically, chick embryos have been extensively used as a model for human biology.

Early last spring, Goodfellow began inoculating chick embryos with a virus strain originally sourced from the Zika outbreak epicenter.

“We wanted a complete animal model, closely to that of a human, which would recapitulate the microcephaly phenotype,” said Goodfellow, who recently presented the findings at the Southern Translational Education and Research (STaR) Conference.

The RBC team, which included Melinda Brindley, an assistant professor of virology in the College of Veterinary Medicine, and Qun Zhao, associate professor of physics in the Franklin College of Arts and Sciences, suggests that the chick embryo provides a useful model to study the effects of Zika, in part because of its significant similarity to human fetal neurodevelopment and rapid embryonic process.

“Now we can look quickly, at greater numbers, to take a closer look at a multitude of different strains and possibly identify the critical window of susceptibility for Zika virus-induced birth defects,” said Brindley. “With this approach, we can continue to further design and test therapeutic efficacy.”
The challenge today is unpredictable disease outbreaks and how to ramp up process and production of therapeutic antibodies in preparation. Having an active pathogen threat like Zika that can jump across continents reinforces the need for therapeutic innovation.

Early stage chick embryos are readily available and low in cost, Goodfellow explained. Development within the egg (in ovo) provides an environment that can be easily accessed by high-speed automation. Poultry automation in the Southeast is impressive, and the industry is now using robotic technology, Goodfellow said.

“With egg injection automation and embryo viability technology, we could test tens of thousands of potential therapeutic compounds in a single day,” he said.
Since 2011, under the mentorship of Steven Stice, a Georgia Research Alliance Eminent Scholar and director of the Regenerative Bioscience Center, Goodfellow has worked extensively with eggs and chickens. In a previous project with Stice and Zhao, the team developed a unique approach of marrying stem cell biology and MRI to track and label neural stem cells.

“We knew we could look at the brain structure, shape and size with MRI, but what we captured was evidence that the infection caused MRI-visible damage, and the total brain volume was substantially smaller,” said Stice, faculty lead and principal investigator of the study. “From this finding, our data provides a rationale for targeting future therapeutic compounds in treating early-stage microcephaly to stop or slow the progress of the disease.”

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Progesterone Promotes Healing In The Lung After A Bout Of Flu

Over 100 million women are on hormonal contraceptives. All of them contain some form of progesterone, either alone or in combination with estrogen. A study published on Sept. 15th in PLOS Pathogens reports that treatment with progesterone protects female mice against the consequences of influenza infection by reducing inflammation and improving pulmonary function, primarily through upregulation of amphiregulin in lung cells.

Progesterone signals through progesterone receptors present on many immune cells (e.g., NK cells, macrophages, dendritic cells, and T cells) and other cells throughout the body. In general, progesterone appears to dampen immune responses and reduce inflammation. Although the immunomodulatory effects of progesterone-based contraception have been studied in the context of sexually transmitted diseases such as HIV and herpes simplex virus, the potential impact of progesterone on viral infections outside of the reproductive tract has not received much attention.

In the present study, Sabra Klein, from Johns Hopkins University in Baltimore, USA, and colleagues examined whether levels of progesterone that mimic physiological concentrations present after ovulation (and equivalent to levels used in contraceptives) influence the host response to influenza infection. The researchers studied female mice whose ovaries had been removed and whose progesterone was supplied by implanted pellets that kept hormone levels constant.

When female mice were challenged with influenza virus, the researchers found that the exogenous progesterone was able to protect females from the consequences of influenza infection to some extent. Progesterone did not reduce the level of virus present in the mice, but decreased the amount of inflammation and tissue damage in the lungs and promoted faster recovery from the infection.

Consistent with this, the researchers found that progesterone treatment was associated with elevated levels of immune cells called T helper 17 (Th17) cells, which are known to be involved in maintaining mucosal barriers and pathogen clearance at mucosal cell surfaces. Progesterone also increased the levels of a protein called amphiregulin (AREG).

When the researchers supplied AREG to progesterone-depleted influenza-infected females, their disease and recovery characteristics resembled those of females on progesterone treatment. This suggests that progesterone exerts its effects through boosting of AREG levels in the lungs. The researchers were able to support this further with data from mice lacking AREG–in these females, progesterone failed to protect against the serious consequences of influenza infection.

To assess the contribution of progesterone treatment to the repair of damaged lung tissue, the researchers studied mouse respiratory cell cultures that had been mechanically injured. Progesterone increased the levels of AREG following injury in these cultures, as well as the speed of the subsequent wound repair.

“Progesterone”, the researchers conclude, “causes protection against severe outcome from influenza by inducing production of the epidermal growth factor, amphiregulin, by respiratory epithelial cells”. Their study illustrates, they say, “that sex hormone exposure, including through the use of hormonal contraceptives, has significant health effects beyond the reproductive tract”.

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Improved Pneumonia Treatment Focus Of Current MSU Research

Streptococcus pneumoniae likely is not a term immediately recognizable by most individuals, even if they have had unpleasant run-ins with the common bacterium. However, experts at Mississippi State University are pioneering pathways to new treatment options.

Primarily affecting those at opposite ends of a typical lifespan, it can cause ear infections in young children and serious cases of pneumonia in adults over 65. While illnesses caused by the bacterium can be treated with antibiotics, the infection may evolve into sepsis—a serious blood disorder—if a case of pneumonia is not responded to quickly.

For those at any age, it is a common complication of influenza.

That’s the bad news.

The good news is that help may be on the way from Mississippi State University’s College of Veterinary Medicine.

Dr. Bindu Nanduri, an associate professor in CVM’s basic sciences department, has discovered new information about the genes in the bacterium and how changes in them can enable better treatment and vaccination options.

In explaining her investigation, Nanduri began with the interior of human nasal cavities where the bacteria live and can spread when a body’s immune system is compromised.

She used the example of a child suffering with the common cold who is unable to fight off infection. In that scenario, the bacteria forms in the middle ear, becomes an infection that takes the form of any of 90 different strains and becomes a challenge to cure.

While a number of vaccines are available, Nanduri said none can “carry all of the strains and, because of that, treatment and limiting the infection is very difficult.”

Medication overuse leading to antibiotic resistance is an additional complication. “The bacteria cannot survive without a host, and, in these cases, the hosts are humans,” she said.

Nanduri holds a master’s degree in biosciences from the University of Roorkee in India and a doctorate in biochemistry and microbiology from the University of Arkansas for Medical Sciences in Little Rock. She is a widely sought authority in bioinformatics, the development of computer software to better understand biological data.

At the MSU veterinary college, “We are removing certain genes in the bacteria that make it impossible for it to survive in the host” and “creating treatments that remove those integral genes so that survival in the body is not possible,” she said.

Dr. Stephen Pruett, basic sciences department head, said Nanduri’s research in pathogen-host interactions has helped multidisciplinary centers at the land-grant institution earn a major grant from the National Institutes of Health’s Centers of Biomedical Research Excellence. COBRE grants are highly competitive, he emphasized.

Designed to support a framework for their investigations of pathogen-host interactions, the federal grant covers Nanduri’s CVM research and that of colleagues at the campus institutes of Genomics, Biocomputing and Biotechnology, and Imaging and Analytical Technologies.

Pruett said Nanduri’s discoveries are providing pathways to new treatment options.
“These ‘mutants’ that Dr. Nanduri produces by removing components are much more easily contained by human immune systems,” he said. “Thus, the medications that would produce this change in the bacteria and block their movement are an entirely new category of treatments.”

According to public health officials, pneumonia causes approximately 1.1 million hospital admissions in the U.S. each year—and 53,000 deaths.

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Smallest-Reported Artificial Virus Could Help Advance Gene Therapy

Gene therapy is a kind of experimental treatment that is designed to fix faulty genetic material and help a patient fight off or recover from a disease. Now scientists have engineered the smallest-reported virus-like shell that can self-assemble. It could someday carry potentially therapeutic DNA or RNA and transfer it to human cells. The report appears in the Journal of the American Chemical Society.

The story of gene therapy is fraught with much hype and high-profile failures. But, hype and failures aside, it remains a promising route to treat a range of ailments, from rare genetic diseases to common conditions such as diabetes. Clinical trials to test various gene therapy treatments are underway. One possible approach is to copy the way viruses behave. When they infect people, viruses inject their genetic material into human cells. Artificial viruses have been engineered to mimic this step, but they tend to clump or are not uniform in size, which can hinder their effectiveness. Max Ryadnov and colleagues wanted to address these issues.

Rather than using full proteins, the researchers used short peptide sequences designed to assemble into tiny gene carriers, which are smaller than previously reported synthetic viruses and even naturally occurring viruses. Lab testing showed that their artificial viral shells were uniform in size and didn’t clump. The particles could encase DNA or RNA and transfer the genetic material to human cells without harm. Depending on the introduced material, the recipient cells then either expressed a new protein or stopped expressing their own protein.

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Deadly Bacteria Share Weapons to Outsmart Antibiotics

Bacteria are rapidly developing resistance mechanisms to combat even the most effective antibiotics. Each year in the United States over 23,000 people die as a result of bacterial infections that have no treatment options, according to the Centers for Disease Control. Infections with antibiotic-resistance bacteria are extremely difficult to treat, requiring costly or toxic medications that do not always work. Scientists are constantly working to understand the mechanisms bacteria use to outsmart antibiotics and develop resistance. These mechanisms include metallo-β-lactamases (MBLs), enzymes produced by bacteria that can bind to and inactivate antibiotics. Enzymes like MBLs are one way bacteria are defying all available tools and becoming antibiotic resistant.

A team of researchers at Case Western Reserve University (CWRU), Massachusetts Institute of Technology, and Universidad Nacional de Rosario and the National Research Council (CONICET) from Argentina have identified a bacterial mechanism that stabilizes certain MBLs in cell membranes and enables their spread into the environment. This mechanism clarifies one way certain bacteria are outsmarting the immune system and becoming extremely antibiotic-resistant. The work was led in part by Robert Bonomo, MD, professor of medicine, pharmacology, molecular biology, and microbiology at Case Western Reserve University School of Medicine and chief of medical service at the Louis Stokes Cleveland Veterans Affairs Medical Center.

“One of the most serious problems facing medicine today is the emergence of multi-drug resistant bacteria,” according to Bonomo. “MBLs are the most concerning as they make bacteria resistant to the ‘last resort’ antibiotics, carbapenems.” Carbapenems are used to combat infections for which there are no other antibiotic options.

Clinically relevant MBLs are found between layers of bacterial cell membranes. In contrast to other types of carbapenemases, MBL enzymes rely on zinc ions to properly function. The immune system produces proteins that hide zinc ions and starve bacteria of zinc in an effort to combat infection. The researchers discovered that most MBLs produced by bacteria during zinc-limited conditions are unstable and are rapidly degraded by the bacteria.

One recently identified form of MBL, called New Delhi metallo-β-lactamase (NDM-1) can retain its function even without zinc. Bonomo and colleagues showed that NDM-1 resists destruction triggered by low zinc by anchoring itself in bacterial membranes. A fatty tail at one end of the NDM-1 protein sticks into the outer membrane of potentially harmful bacteria such as Escherichia coli and Pseudomonas aeruginosa. This tail has a protective effect and is thought to help NDM-1 avoid destructive enzymes between bacterial membranes. Similar mechanisms have been observed in other bacterial species, but have not previously been linked to an evolutionary advantage to escape the action of antibiotics.

The research team also observed that bacteria with NDM-1 in their membranes are also able to shed “outer-membrane vesicles” containing the enzyme. These membrane-bound sacs bud off from bacteria. As the vesicles disperse into the bacterial microenvironment, NDM-1 enzymes in them can protect neighboring bacteria that might be otherwise susceptible to antibiotics. Outer-membrane vesicles may also be a vehicle by which the NDM-1 gene and enzyme can spread between bacteria.

Bacteria producing NDM-1 are highly antibiotic resistant and represent a major public health concern as they cause infections for which there is no cure. The gene encoding NDM-1 is quickly spreading across bacterial species and has been found in water samples from India, Bangladesh, and China in a region encompassing almost 40% of the world population.

According to Alejandro Vila, PhD, director of the Instituto de Biología Molecular y Celular at Universidad Nacional de Rosario and co-senior author on the published research, “this dissemination has been favored by membrane anchoring of the protein. This finding reveals a potential Achilles’ heel; interfering with membrane anchoring could thwart the worldwide dissemination of superbugs.”

Together, the studies by Bonomo, Vila, and colleagues provide clarity on the bacterial mechanism behind one of the most prevalent bacterial carbapenemase identified to date, NDM-1. Understanding the mechanism “allows us to begin considering novel agents that can target this process,” according to. Bonomo. New potential targets for antibacterial drug development could include the lipid tail of NDM-1 or outer membrane vesicles.

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Largest HIV Transmission Study Conducted

A new study has found that neither gay men nor heterosexual people with HIV transmit the virus to their partner, provided they are on suppressive antiretroviral treatment.

The PARTNER study, which is the world’s largest study of people with HIV who have had condomless sex with their HIV negative partners, was conducted by investigators from the University of Liverpool, University College London, Royal Free NHS and Rigshospitalet (one of the largest hospitals in Denmark).

This work was funded by the National Institute for Health Research (NIHR) and was sponsored by UCL (University College London).

More than 800 couples monitored

The study monitored 888 couples from 14 different European countries, in which one of the partners was on effective treatment for HIV. Of the 888 couples, 548 were heterosexual and 340 were gay men.

All the couples had sex regularly without using a condom. They have now been monitored for several years and not one instance of transmission of the virus has been recorded. The results have just been published in the prestigious Journal of the American Medical Association.

In the period following the study, a total of 11 HIV-negative partners were infected with HIV. Led by Professor Anna Maria Geretti, researchers from the University of Liverpool‘s Institute of Infection and Global Health undertook phylogenetic analyses of the 11 new HIV cases and their partners’ virus.

No HIV transmission between couples

Professor Geretti, said: “The HIV virus can be divided into several sub-groups, each with its own genetic characteristics, and this makes it possible to see whether the virus is genetically similar to a partner’s. In all cases the results showed that the virus came from someone other than the partner under treatment.

“This research is vital for us to gain an even better understanding the risks associated with this particular virus.”

Professor Jens Lundgren from Rigshospitalet, senior author of the study and head of CHIP (the Centre for Health and Infectious Diseases), said: “The results clearly show that early diagnosis of HIV and access to effective treatment are crucial for reducing the number of new HIV cases. As soon as a patient with HIV is on treatment with a suppressed viral load, the risk of transmission becomes minimal.”

More data on the way

Gay couples in the study will continue to be monitored for three more years to obtain even more data in this area for anal sex.