Study finds ‘important implications’ to understanding immunity against COVID-19

New research from Emory University indicates that nearly all people hospitalized with COVID-19 develop virus-neutralizing antibodies within six days of testing positive. The findings will be key in helping researchers understand protective immunity against SARS-CoV-2 and in informing vaccine development. The test that Emory researchers developed also could help determine whether convalescent plasma from COVID-19 survivors can provide immunity to others, and which donors' plasma should be used. The antibody test developed by Emory and validated Read more

Emory plays leading role in landmark HIV prevention study of injectable long-acting cabotegravir

Emory University played a key role in a landmark international study evaluating the safety and efficacy of the long-acting, injectable drug, cabotegravir (CAB LA), for HIV prevention. The randomized, controlled, double-blind study found that cabotegravir was 69% more effective (95% CI 41%-84%) in preventing HIV acquisition in men who have sex with men (MSM) and transgender women who have sex with men when compared to the current standard of care, daily oral emtricitabine/tenofovir disoproxil fumarate Read more

Yerkes researchers find Zika infection soon after birth leads to long-term brain problems

Researchers from the Yerkes National Primate Research Center have shown Zika virus infection soon after birth leads to long-term brain and behavior problems, including persistent socioemotional, cognitive and motor deficits, as well as abnormalities in brain structure and function. This study is one of the first to shed light on potential long-term effects of Zika infection after birth. “Researchers have shown the devastating damage Zika virus causes to a fetus, but we had questions about Read more

CXCR5

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

Posted on by Quinn Eastman in Immunology Leave a comment