Wound repair of mucous tissues during early infection by Simian Immunodeficiency Virus guards some primate species from contracting AIDS, a study has learned. The researchers looked at why certain species can carry SIV throughout their lives without getting AIDS.
SIV is closely related to HIV, or the Human Immunodeficiency Virus, and has become a laboratory model for studies seeking AIDS and HIV cures and prevention.
During early infection, both HIV and SIV provoke an immune response that injures tissues surrounding the intestine. In people and some other primates, this injury allows bacteria that normally reside in the gut to penetrate the tissue and invade other sites in the body. Inflammation and damage result. The situation attracts more immune cells. Some are attacked by the virus. Others undergo spontaneous cell death. As disease-fighting T cells decline, the immune system deteriorates.
In contrast, African green monkeys respond to an SIV infection by quickly repairing and regenerating their mucous tissues. This preserves tissue integrity, and interrupts the inflammatory course of the disease that exhausts the immune system. The onset of AIDS is avoided.
The findings suggest that developing therapies that stimulate the wound healing response during early HIV infection could avoid progression to AIDS.
Michael Gale, Jr., professor of immunology, University of Washington School of Medicine; Frederick Barrenas, University of Uppsala, Sweden, and Jan Komorowski, Institute of Computer Sciences, Polish Academy of Sciences, led the multi-institutional study.