Researchers have identified an immune cell population that acts as the body's border patrol with the outside world and limit the inner body's exposure to allergens, pollutants, viruses, bacteria, and parasites.
David Artis of the University of Pennsylvania School of Medicine, and Gregory F. Sonnenberg of the Artis lab discovered that these lymphoid tissue inducer cells maintain immunity in the intestine of mice.
Following infection by Citrobacter rodentium-a model of human E. coli infection in the gut-this cell population was the dominant source of IL-22, a molecule that helps in the immune response during the early phases of infection.
When the inducer cells were eliminated from the intestine of the experimental mice, immunity was impaired, affecting the production of anti-microbial proteins required to fight infection. The mice eventually died.
This discovery could also represent a new line of research for HIV/AIDS since there is a breakdown of barrier immunity in the gut that can lead to full blown AIDS, said Artis. Therapeutics to target such immune cells could be an important new way to combat AIDS.
The research appeared in the journal Immunity.