0448 GMT September 23, 2019
The study, published in the Journal of Experimental Medicine, may lead to a possible vaccine that stimulates the production of antibodies to neutralize the HIV-1 virus, UPI reported.
Some patients infected with HIV-1 develop broadly neutralizing antibodies, or bnAbs, that protect against a variety of HIV-1 strains by recognizing a protein on the surface of the virus called Env, which develops after several years of infection.
Researchers theorize that because of shared features of HIV-1 bnAbs, there is an inability to make the protective antibodies against HIV because the immune system suppresses their production — which prevents the body from creating self-reactive antibodies that cause autoimmune diseases like systemic lupus erythematosus.
However, patients with lupus have slower rates of HIV-1 infection, which could be caused by self-reactive antibodies that recognize and neutralize HIV-1.
This process is known as immunological tolerance, and researchers used mice with genetic defects of lupus-like symptoms to test their theory.
Raul M. Torres, professor of immunology and microbiology at the University of Colorado School of Medicine, said, "We wanted to see if people could make a protective response to HIV-1 without the normal restraint imposed by the immune system to prevent autoimmunity.”
The study found the production of HIV-neutralizing antibodies correlated with levels of a self-reactive antibody that recognizes the chromosomal protein Histone H2A.
"We think this may reflect an example of molecular mimicry where the virus has evolved to mimic or look like a self-protein," Torres said, adding that this could explain the difficulty in developing a vaccine for HIV-1.
"But breaching peripheral immunological tolerance permits the production of cross-reactive antibodies able to neutralize HIV-1."