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

Reddit as window into opioid withdrawal strategies

Drug abuse researchers are using the social media site Reddit as a window into the experiences of people living with opioid addiction. Abeed Sarker in Emory's Department of Biomedical Informatics has a paper in Clinical Toxicology focusing on the phenomenon of “precipitated withdrawal,” in collaboration with emergency medicine specialists from Penn, Rutgers and Mt Sinai. Precipitated withdrawal is a more intense form of withdrawal that can occur when someone who was using opioids starts medication-assisted treatment Read more

CROI: HIV cure report and ongoing research

The big news out of CROI (Conference on Retroviruses and Opportunistic Infections) was a report of a third person being cured of HIV infection, this time using umbilical cord blood for a hematopoetic stem cell transplant. Emory’s Carlos del Rio gave a nice overview of the achievement for NPR this morning. As del Rio explains, the field of HIV cure research took off over the last decade after Timothy Brown, known as “the Berlin patient,” Read more

immunology and molecular pathogenesis

Bird flu shuffle probes viral compatibility

When influenza viruses that infect birds and humans meet in the same cell, they can shuffle their genomes and produce new strains that might have pandemic potential. Think of this process, called reassortment, as viruses having sex.

In the last several years, public health officials have been monitoring two varieties of bird flu viruses with alarming properties: H7N9 and H5N8. Scientists at Emory have been probing the factors that limit reassortment between these strains and a well-known strain (H3N2) that has been dominating the last few flu seasons in the United States.

Helen Branswell has an article in STAT this week, explaining that H5N8 actually emerged from reassortment  involving much-feared-but-not-damaging-to-humans-so-far H5N1:

Several years ago, these viruses effectively splintered, with some dumping their N1 neuraminidase — a gene that produces a key protein found on the surface of flu viruses — and replacing it with another. The process is called reassortment, and, in this case, it resulted in the emergence of a lot of new pairings over a fairly short period of time.

The most common and most dangerous viruses to emerge — for birds at least — have been H5N6 and H5N8 viruses. Both are highly pathogenic, meaning they kill domestic poultry.

“The H5N1 virus has not gone away. It’s just changed into different versions of itself,” explained influenza expert Malik Peiris, a professor of virology at the University of Hong Kong.

From the Emory study, the good news is that “packaging signals” on the H5 and H7 viral RNA genomes are often incompatible with the H3N2 viruses. That means it could be difficult for segments of the genome from the bird viruses to get wrapped up with the human viruses. But mix and match still occurred at a low level, particularly with H5N8. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Antibody production: an endurance sport

Antibodies defend us against infections, so they often get described as weapons. And the cells that produce them could be weapon factories?. To understand recent research from immunologist Jerry Boss’s lab, a more appropriate metaphor is the distinction between sprinting and long-distance running.

Graduate student Madeline Price in Boss’s lab has been investigating how antibody-producing cells use glucose – the simple sugar– and how the cells’ patterns of gene activity reflect that usage. Cells can use glycolysis, which is inefficient but fast, analogous to sprinting, or oxidative phosphorylation, generating much more energy overall, more like long distance running.

As Boss and Price point out:

Immunology + Molecular Pathogenesis graduate student Madeline Price

Glycolytic metabolism produces 2 molecules of ATP per molecule of glucose, while oxidative phosphorylation produces 36 molecules of ATP from the same starting glucose molecule. Where oxidative phosphorylation generates more energy from ATP, glycolysis generates metabolic intermediates that are also useful for rapid cellular proliferation.

In their recent paper in Cell Reports, they lay out what happens to B cells, which can go on to become antibody secreting cells (ASCs), after an initial encounter with bacteria. The B cells first proliferate and upregulate both glycolysis and oxidative phosphorylation. However, upon differentiating, the cells shift their preference to oxidative phosphorylation. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

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

Emory labs on LabTV

This summer, video producers from the web site LabTV came to two laboratories at Emory. We are pleased to highlight the first crop of documentary-style videos.

LabTV features hundreds of young researchers from universities and institutes around the United States, who tell the public about themselves and their research. The videos include childhood photos and explanations from the scientists about what they do and what motivates them. Screen Shot 2015-12-18 at 9.14.51 AM

The two Emory labs are: Malu Tansey’s lab in the Department of Physiology, which studies the intersection of neuroscience and immunology, focusing on neurodegenerative disease, and Mike Davis’ lab in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, which is developing regenerative approaches and technologies for heart disease in adults and children. Read more

Posted on by Quinn Eastman in Heart, Immunology, Neuro Leave a comment