Warren symposium follows legacy of geneticist giant

If we want to understand how the brain creates memories, and how genetic disorders distort the brain’s machinery, then the fragile X gene is an ideal place to start. That’s why the Stephen T. Warren Memorial Symposium, taking place November 28-29 at Emory, will be a significant event for those interested in neuroscience and genetics. Stephen T. Warren, 1953-2021 Warren, the founding chair of Emory’s Department of Human Genetics, led an international team that discovered Read more

Mutations in V-ATPase proton pump implicated in epilepsy syndrome

Why and how disrupting V-ATPase function leads to epilepsy, researchers are just starting to figure Read more

Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more

Rama Rao Amara

Multiple myeloma patients display weakened antibody responses to mRNA COVID vaccines

A new study reports weakened antibody responses to COVID-19 mRNA vaccines among most patients with multiple myeloma, a form of bone-marrow cancer associated with an immunocompromised state.

The research, published in the journal Leukemia, was carried out at the Institute for Myeloma and Bone Cancer Research (IMBCR) in California, in collaboration with Emory infectious diseases fellow Samuel Stampfer, MD, PhD.

Patients with smoldering myeloma, not requiring treatment, all achieved a good response to COVID-19 vaccination, whereas less than half of patients with active myeloma requiring treatment did. Specifically, only 45 percent of active patients fully responded to the mRNA vaccines, whereas less than a quarter showed a partial response and one-third did not respond to the vaccines above background antibody levels.

Serum samples from 103 multiple myeloma patients were obtained prior to vaccination and 2-3 weeks after administration of the first and second vaccines, and compared to a group of age‑matched healthy controls. Predictors of reduced antibody responses to the vaccines included: older age, impaired renal function, low lymphocyte counts, reduced uninvolved antibody levels, past first line of treatment, and those not in complete remission. Nearly two-thirds of patients who received the Moderna vaccine responded to a level thought to be clinically significant, whereas only approximately a quarter who received the Pfizer vaccine did.

“Based on these data, myeloma patients may need to continue social distancing following COVID-19 vaccination, and postvaccine antibody tests may help guide decisions regarding supplementary vaccination or antibody prophylaxis for this vulnerable population,” says Stampfer, who co-designed the clinical study, under the guidance of senior author James Berenson, MD, the Scientific and Medical Director of IMBCR.

“This study highlights the importance of recognizing the limitations of current vaccination approaches to COVID-19 for immunocompromised patients, and that new approaches will have to be developed to improve their protection from this dangerous infection,” Berenson says. “It also suggests that there may be clinically significant differences in the effectiveness of different COVID-19 vaccines for immune compromised patients. Until these advances occur, it means that myeloma patients will need to remain very careful even if they have been vaccinated through wearing their masks and avoiding contact with unvaccinated individuals.”.

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Posted on by Quinn Eastman in Cancer, Immunology Leave a comment

Emory MVA COVID-19 Vaccine Safe and Effective in Animal Models

Researchers at Yerkes National Primate Research Center, Emory University, have developed a COVID-19 vaccine that has proven safe and effective in mice and monkeys. Results from this National Institute of Allergy and Infectious Diseases (NIAID)-funded study were published online Thursday, Feb. 4 in Immunity.

The Emory MVA COVID-19 vaccine induces protective immunity with the platform of modified vaccinia Ankara (MVA), a harmless version of a poxvirus that is well-known for its use in HIV/AIDS vaccines. Like the Moderna and Pfizer COVID-19 vaccines, the Emory MVA COVID-19 vaccine induces strong neutralizing antibodies, which support the immune system’s ability to fight infections. The Emory MVA COVID-19 vaccine also induces killer CD8 T cells, providing a multi-pronged approach to halting SARS-CoV-2.

In addition, the Emory researchers say the vaccine is easily adaptable to address disease variants and can be used in combination with existing vaccines to improve their ability to combat variants and has the potential to be equally effective with a single dose.

Lead researcher Rama Amara, PhD, built the Emory MVA COVID-19 vaccine based on his more than 20 years of experience working with MVA and animal models to develop an HIV/AIDS vaccine. He and his Yerkes-based research team tested two MVA SARS-CoV-2 vaccines in mice. One of them, MVA/S, used the complete spike protein of coronavirus to induce strong neutralizing antibodies and a strong killer CD8 T cell response against SARS-CoV-2.

“Generating neutralizing antibodies is an important component of a successful COVID-19 vaccine because the antibodies can block the virus from entering the body’s cells,” says Amara, Charles Howard Candler professor of microbiology and immunology at Emory University School of Medicine and a researcher in Yerkes’ Division of Microbiology and Immunology and Emory Vaccine Center. “It’s as important to activate CD8 T cells that can clear infected cells, so this allows us to approach halting the virus two ways simultaneously. The CD8 T cells also provide ongoing value because they are key to working against other variants of the virus, especially if antibodies fail.”

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In current vaccine research, adjuvants are no secret

Visionary immunologist Charlie Janeway was known for calling adjuvants – vaccine additives that enhance the immune response – a “dirty little secret.”

Charlie Janeway, MD, in a hat he wore often

Janeway’s point was that foreign antigens, by themselves, were unable to stimulate the components of the adaptive immune system (T and B cells) without signals from the innate immune system. Adjuvants facilitate that help.

By now, adjuvants are hardly a secret, looking at some of the research that has been coming out of Emory Vaccine Center. This week, an analysis by Ali Ellebedy, now at Washington University St Louis, and colleagues showed that in healthy volunteers, the AS03 adjuvant boosted otherwise poor immune responses to a limited dose of the exotic avian flu H5N1, recruiting both memory and naïve B cells. More on that here.

The Moderna SARS-CoV-2 vaccine, which has shown some activity in a small clinical trial here at Emory, has its own kind of adjuvant, since it’s made of both innate-immune-stimulating mRNA and clothed in lipid nanoparticles. Extra adjuvants may come into play later, either with this vaccine or others.

A question we’ve seen many people asking, and discussed on Twitter etc is this: how long does the immunity induced by a SARS-CoV-2 vaccine last? How can we make the immune cells induced by a vaccine stick around for a long time? Read more

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Access to HIV’s hideouts: T cells that take on their own

Police procedural television shows, such as Law + Order, have introduced many to the Internal Affairs Bureau: police officers that investigate other police officers. This group of unloved cops comes to mind in connection with the HIV/AIDS research published this week by Rama Amara’s lab at Yerkes National Primate Research Center and Emory Vaccine Center.

“Killer” antiviral T cells (red spots) can be found in germinal centers. The green areas are B cell follicles, which HIV researchers have identified as major reservoirs for the virus. Image courtesy of Rama Amara.

HIV infection is hard to get rid of for many reasons, but one is that the virus infects the cells in the immune system that act like police officers. The “helper” CD4 T cells that usually support immune responses become infected themselves. For the immune system to fight HIV effectively, the “killer” CD8 antiviral T cells would need to take on their own CD4 colleagues.

When someone is HIV-positive and is taking antiretroviral drugs, the virus is mostly suppressed but sticks around in a reservoir of inactive infected cells. Those cells hide out in germinal centers, specialized areas of lymph nodes, which most killer antiviral T cells don’t have access to. A 2015 Nature Medicine paper describes B cell follicles, which are part of germinal centers, as “sanctuaries” for persistent viral replication. (Imagine some elite police unit that has become corrupt, and uniformed cops can’t get into the places where the elite ones hang out. The analogy may be imperfect, but might help us visualize these cells.)

Amara’s lab has identified a group of antiviral T cells that do have the access code to germinal centers, a molecule called CXCR5. Knowing how to induce antiviral T cells displaying CXCR5 will be important for designing better therapeutic vaccines, as well as efforts to suppress HIV long-term, Amara says. The paper was published in PNAS this week. Read more

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The cure word, as applied to HIV

HIV researchers are becoming increasingly bold about using the “cure” word in reference to HIV/AIDS, even though nobody has been cured besides the “Berlin patient,” Timothy Brown, who had a fortuitous combination of hematopoetic stem cell transplant from a genetically HIV-resistant donor. Sometimes researchers use the term “functional cure,” meaning under control without drugs, to be distinct from “sterilizing cure” or “eradication,” meaning the virus is gone from the body. A substantial obstacle is that HIV integrates into the DNA of some white blood cells.

HIV cure research is part of the $35.6 million, five-year grant recently awarded by the National Institutes of Health to Yerkes/Emory Vaccine Center/Emory Center for AIDS Research. Using the “shock and kill” approach during antiviral drug therapy, researchers will force HIV (or its stand-in in non-human primate research, SIV) to come out of hiding from its reservoirs in the body. The team plans to test novel “latency reversing agents” and then combine the best one with immunotherapeutic drugs, such as PD-1 blockers, and therapeutic vaccines.

The NIH also recently announced a cluster of six HIV cure-oriented grants, named for activist Martin Delaney, to teams led from George Washington University, University of California, San Francisco, Fred Hutchinson Cancer Research Center, Wistar Institute, Philadelphia, Beth Israel Deaconess Medical Center and University of North Carolina. Skimming through the other teams’ research plans, it’s interesting to see the varying degrees of emphasis on “shock and kill”/HIV latency, enhancing the immune response, hematopoetic stem cell transplant/adoptive transfer and gene editing weaponry vs HIV itself.

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HIV vaccine news: a glass half full

This week, researchers from Yerkes and Emory Vaccine Center led by Cindy Derdeyn published a paper that I first thought was disturbing. It describes how monkeys vaccinated against HIV’s relative SIV (simian immunodeficiency virus) still become infected when challenged with the virus. Moreover, it’s not clear whether the vaccine-induced antibodies are exerting any selective pressure on the virus that gets through.

But then I realized that this might be an example of “burying the lead,” since we haven’t made a big hoopla about the underlying vaccine studies, conducted by Rama Amara. Some of these studies showed that a majority of monkeys can be protected from repeated viral challenge. The more effective vaccine regimens include adjuvants such as the immune-stimulating molecules GM-CSF or CD40L (links are the papers on the protective effects). Read more

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Adjuvants: once immunologists’ “dirty little secret”

Two presentations on Emory research at last week’s AIDS Vaccine 2010 conference concerned adjuvants. These are substances that act as amplifiers, stimulating the immune system while keeping its focus on the specific components of a vaccine.

Charlie Janeway (1943-2003)

Immunologist Charlie Janeway once described adjuvants as immunology’s “dirty little secret,” because for a long time scientists did not know how they worked. Some adjuvants can sound irritating and nasty, such as alum and oil emulsion. Alum is the only vaccine adjuvant now licensed for human clinical use in the US. Over the last few years, scientists have learned that adjuvants rev up what is now known as the “innate immune system,” so that the body knows that the vaccine is something foreign and dangerous.

Rama Rao Amara, a vaccine researcher at Emory Vaccine Center and Yerkes National Primate Research Center, and Harriet Robinson, former head of microbiology and immunology at Yerkes and now chief scientific officer at the firm GeoVax, both described extra ingredients for the DNA/MVA vaccine that Robinson designed while at Yerkes in collaboration with NIH researchers.

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