The Secret Behind HIV Infection Found: Reasons Why It Could Not Be Eradicated

Specialized cells in the intestine called Paneth cells are the first to respond to HIV infection. Researchers at UC Davis conducted a study that looked into the bodily responses to the deadly HIV infection. Satya Dandekar, lead author of the study and chair of the Department of Medical Microbiology and Immunology at UC Davis, said that they wanted to understand what enables the HIV virus to invade the gut, cause inflammation and kill the immune cells.

The team found that the Paneth cells, when responding to the virus, produces a cytokine called interleukin-1 beta (IL-1β ), which causes gut inflammation. Though the IL-1β is aimed at the virus, it breaks down the gut lining. The epithelium or gut lining serves as a barrier that protects the body against pathogens. Satya explained that Paneth cells are the "initial virus sensors" that causes tissue damage and helps in spreading the infection. "Our findings provide potential targets and new biomarkers for intervening or blocking early spread of viral infection," she added.

They also found that this happens during the early stages of the infection, even before it begins spreading. However, the study found a way to alleviate the virus-induced inflammatory response -- the bacterium Lactobacillus plantarum, which helps in protecting the gut lining.

The researchers observed that within 2.5 days of viral infection, a very small number of infected cells has been detected in the gut. The gut immediately responded with inflammation in the lining, producing IL-1β and reducing the production of "tight-junction proteins." These proteins make the lining resistant to pathogens, and a reduction in their production causes a breakdown in the lining. The report, being the first of its kind, shows that the immune system is dependent on more factors than just the immune cells.

First, author Lauren Hirao explained that the epithelium is more than a physical barrier; it helps immune cells by being a barrier against viruses and bacteria. The reason behind the inability to overcome the infection and recover the immune system is because of the "HIV reservoir in the gut," the report stated. However, researchers state that there is only a small amount of information regarding this.

They also found way of reversing the damage: the specific-probiotic strain, Lactobacillus plantarum reduces the IL-1β production and this helps tackle the inflammation and trigger the repair of the lining. Hirao said that this would be extremely essential in the development of new therapies to counter the effects of the viral infection. "Seeing how these events play out can help us find the most opportune moments to intervene," Hirao added.

The study was published in the journal PLoS Pathogens.