Exosomes as potential biomarkers of radiation exposure

Exosomes = potential biomarkers of radiation in the Read more

Before the cardiologist goes nuclear w/ stress #AHA17

Measuring troponin in CAD patients before embarking on stress testing may provide Read more

Virus hunting season open

Previously unknown viruses, identified by Winship + UCSF scientists, come from a patient with a melanoma that had metastasized to the Read more

National Institute of Allergy and Infectious Diseases

Update on SIV remission studies

Tab Ansari’s research at Emory/Yerkes on how an antibody treatment can push monkeys infected with SIV into remission was published in Science last year. At that time, Ansari told Lab Land about follow-up experiments to probe which immune cells are needed for this effect, which surprised many HIV/AIDS experts.

Ansari’s partner on the project, NIAID director Anthony Fauci, described the follow-up work in July at the International AIDS Society Conference in Paris. We thank Treatment Action Group’s Richard Jefferys for taking notes and posting a summary:

The approach that the researchers took was to deplete different types of immune cells in the animals controlling SIV viral load, then assess whether this led to an increase in viral replication. The experiments compared:

*Antibodies to the CD8 receptor alpha chain, which deplete CD8 T cells, natural killer T cells (NKTs) and natural killer (NK) cells

*Antibodies to the CD8 receptor beta chain, which deplete CD8 T cells

*Antibodies to CD20, which deplete B cells

According to Fauci’s slides, which are available online, there was a transient rebound in viral load with the CD8 alpha antibody and to a small degree with the CD8 beta. This suggests NKTs and NK cells are making a contribution to the observed control of SIV replication, but a role for CD8 T cells cannot be ruled out.

For comparison, a study from Guido Silvestri and colleagues at Yerkes published in 2016 found that treating SIV-infected monkeys with anti-CD8 antibodies, without stopping antiretroviral drugs, resulted in a rebound in virus levels. [They used ultrasensitive assays to detect the rebound.] However, the Yerkes team only used antibodies to the CD8 receptor alpha chain.

Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Clues to how anti-integrin antibody suppresses SIV

In October 2016, Emory and NIAID researchers published results in Science that surprised the HIV/AIDS field.

They showed that treatment with an antibody, on top of antiretroviral drugs, could lead to long-term viral suppression in SIV-infected monkeys. A similar antibody is already approved for Crohn’s disease, and a clinical trial has begun at NIAID testing the effects in people living with HIV.

The HIV/AIDS field is still puzzling over a study led by Emory pathologist Tab Ansari.

All that was achieved even though HIV/AIDS experts are still puzzled by how the antibody works. Last week, Christina Guzzo,with NIAID director Anthony Fauci’s lab, presented new data at the Conference on Retroviruses and Opportunistic Infections in Seattle that provide some clues. But the broader issue of “what is the antibody doing?” is still open.

Let’s back up a bit. The antibody used in the Science paper targets a molecule called integrin alpha 4 beta 7, usually described as a “gut homing receptor” for CD4+ T cells, which are ravaged by HIV and SIV infection.  Study leader Aftab Ansari (right) and Fauci have both said their idea was to stop T cells from circulating into the gut, a major site of damage during acute viral infection.

Integrin alpha 4 beta 7 was also known to interact with the HIV envelope protein. Accordingly, it is possible to imagine some possibilities for what an antibody against integrin alpha 4 beta 7 could be doing: it could be driving T cells to different places in the body or affecting the T cells somehow, or it could be interfering with interactions between SIV and the cells it infects.

The new data from NIAID say that integrin alpha 4 beta 7 is found on the virus itself. This finding makes sense, because SIV and HIV are enveloped viruses — they steal the clothes of the cells they infect and emerge from. [Integrin alpha 4 beta 7 also appears to help the virus be more infectious in the gut, Guzzo’s presentation says.]

So a third possibility appears: the anti-alpha 4 beta 7 antibody is mopping up virus. Perhaps it’s acting like a virus-neutralizing antibody or the anti-CD4 antibody ibalizumab — CD4 is the main viral receptor on T cells. It could explain why the anti-integrin antibody’s effect is so durable; HIV/SIV can mutate to escape neutralizing antibodies directed against the viral envelope protein, but it can’t mutate the clothes it steals! Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Background links on SIV remission Science paper

This was the first consistent demonstration of post-treatment immune control in monkeys infected with SIV, without previous vaccination. Long-term post-treatment control of HIV has been reported in only a handful of people treated soon after infection. To learn more, check out these links.

Transient SIVmac remission induced by TLR7 agonist, reported at 2016 CROI conference

Immune control of SIVagm, no antiretroviral drugs necessary. Model of “elite controllers.”

Immune clearance of SIVmac; prior CMV-based vaccination necessary.

Post-treatment control of HIV – VISCONTI study. Roundup of HIV remission cases, from Treatment Action Group. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

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.

Posted on by Quinn Eastman in Immunology Leave a comment

Transformative awards for Mocarski’s malleable cells, lung fibrosis

The National Institutes of Health has announced a five-year, $1.9 million Transformative Research Award to Emory virologist Edward Mocarski, PhD for his work on how the mechanisms of programmed cell death can be subverted.

Mocarski is Robert W. Woodruff professor of microbiology and immunology at Emory University School of Medicine and Emory Vaccine Center. His research, which originated in probing how cells commit suicide when taken over by viruses, could lead to advances in regenerative medicine and organ transplant.

Barker Mocarski

Thomas Barker, PhD (left) and Edward Mocarski, PhD (right)

The grant, funded through the National Institute of Allergy and Infectious Diseases, is one of nine “high-risk-, high-reward” Transformative Research Awards (13 recipients) announced by the NIH on October 6.

In the same group this year, Thomas Barker in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University received a Transformative Research Award for his research on mechanosensors + pulmonary fibrosis.

The Transformative Research Award program supports “exceptionally innovative, unconventional, paradigm-shifting research projects that are inherently risky and untested.” Emory has achieved only one other TRA since the program was established in 2009: Shuming Nie’s project on imaging to guide cancer surgery. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Children with Food Allergies Offered Better Diagnosis and Treatment with New Guidelines

Twenty years ago, food allergies had barely been heard of. Now, they are a $500 million health problem that affects more than 12 million Americans, including three million children. New federal guidelines issued by the National Institute of Allergy and Infectious Diseases (NIAID) will help physicians better diagnose and treat food allergies, according to Karen Demuth, MD, an assistant professor of pediatrics in the Emory University School of Medicine, and a physician on staff at Children’s Healthcare of Atlanta.

Dr. Demuth was a key player in advancing legislation to call attention to the challenges of food allergies in children. She and several of her patients were on hand to witness Governor Nathan Deal signing a proclamation declaring May 8 to 14 Food Allergy Awareness Week in Georgia.

Dr. Demuth (pictured far right) was a key player in advancing legislation to call attention to the challenges of food allergies in children. She and several of her patients were on hand to witness Governor Nathan Deal signing a proclamation declaring May 8 to 14 Food Allergy Awareness Week in Georgia.

“The new NIAID guidelines help providers understand food allergies,” Demuth says. “They address when we should consider a food allergy and the utility of testing for food allergy. In addition, they address the management of food allergies, including acute reactions and follow-up of individuals with food allergy.”

The guidelines are comprised of input from a panel of 25 experts and draw the important distinction between food allergies and food intolerances. Food allergies are defined as “an adverse health effect arising from a specific immune response hat occurs reproducibly on exposure to a given food.” Food intolerances produce an adverse reaction but are likely not related to an immune response.

The most common food allergies are to milk, eggs, peanuts, tree nuts, shellfish, fish and soy. Fortunately, the understanding of food allergies and the best ways to manage them is expanding.

“The gold standard of treatment of food allergies – avoidance – has remained constant throughout the years,” Demuth says. “There are new therapies on the horizon such as oral immunotherapy, vaccines and a Chinese herbal extract; however, these therapies are still considered experimental. At the Emory-Children’s Center, we are active in research and advocacy in pediatric allergies so that we can bring new treatments to our patients when they are ready for widespread use. We are dedicated solely to the care of children with allergic and immunologic disorders and offer multidisciplinary clinics to offer a specialized level of care.”

Video

Posted on by Kerry Ludlam in Uncategorized Leave a comment

NIAID Director Fauci: link seasonal and pandemic flu preparedness

Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, delivered the keynote address Sunday, April 18, as part of a three-day conference on H1N1 Virus: The First Pandemic of the 21st Century, sponsored by the Emory-UGA Influenza Pathogenesis and Immunology Research Center.

One of the most important lessons from this past year’s pandemic, Fauci said, is the need to “connect the dots” between seasonal and pandemic influenza and not view them as two separate phenomena.

Fauci enthusiastically supports the CDC’s call for universal flu vaccination.

“Rather than trying to figure out one priority group over another,” Fauci said, “if we can get into a rhythm of getting most people vaccinated each year, we will have most of the population with some degree of immunity. We will get into a situation where we don’t need to go from a seasonal approach to a crisis approach.

Read more

Posted on by Holly Korschun in Immunology Leave a comment