research

HIV Uses Host's Own Immune Molecules for Protection

an HIV-infected T cell

In one of Aesop’s classic fables, a clever wolf dons a sheep’s skin in order to move through the herd undetected. As it turns out, IRP researchers have discovered that in people with a specific set of immune system genes, the HIV virus uses a similar approach to hide from the body’s defenses.1

Nearly all cells in our bodies are coated with proteins called human leukocyte antigens (HLAs). These proteins allow the immune system to distinguish between healthy, native cells and those contaminated by unwelcome visitors like viruses or bacteria that must be destroyed. Each of the various HLA proteins is encoded by a different HLA gene and these genes vary considerably between individuals, causing different people to have different variants of each HLA protein.

“There are thousands of different forms of these HLA genes, and that variation allows us, as a species, to deal with virtually all infectious pathogens,” says IRP Senior Investigator Mary N. Carrington, Ph.D., the senior author of the new paper. “We’re really interested in the diversity of that part of the genome, since the risk of essentially every autoimmune disease, many cancers, and probably every infectious disease is associated with this set of genes.”

Twitter Chat Shines Spotlight on Rare Diseases

Between 25 and 30 million Americans have a rare disease, defined as a condition affecting fewer than 200,000 people. On March 1, the NIH will host its annual Rare Disease Day to increase awareness of these under-recognized and often undiagnosed illnesses and highlight the efforts of scientists, patients, and advocates to produce treatments.

In anticipation of the occasion, on February 23, NIH organized a Twitter chat with NIH Director Francis Collins, M.D., Ph.D., and Sharon Terry, President and CEO of Genetic Alliance and a member of the Research Program Advisory Panel for NIH’s All of US project. Check out some of the more noteworthy exchanges below or look at the full Twitter chat by searching for #NIHchat on Twitter.

NIH Rare Disease Day logo

Gut Bugs May Convert High-Fat Fare into Cancer Risk

cartoon image of the gut microbiome showing microbes in the digestive tract

Researchers have a long history of fattening up mice to gain insight into the causes and consequences of weight gain in the human body. In one of the more recent studies of this kind, a team of IRP researchers found that that a high-fat diet consistently altered the collection of microbes residing in mice’s digestive tracts and that this diet-microbe combination might pre-dispose the mice – and, potentially, obese humans – to colon cancer by triggering certain changes in how genes behave.