New research published in PLoS Medecine from the NIAID-funded Center for HIV/AIDS Vaccine Immunology suggests that HIV-1 moves at breathtaking speed in destroying and de-regulating the body's gut-based B-cell antibody-producing system, resulting in a sober reality for hopeful vaccine hunters.
From the Summary:
Soon after infection, immune system cells called B lymphocytes begin to produce HIV-specific antibodies (proteins that recognize viral molecules called antigens). The first antibodies to HIV usually appear two to seven weeks after infection; from about 12 weeks after infection, antibodies are made that can kill the specific HIV type responsible for the infection (neutralizing antibodies).
Unfortunately, by this time, it is too late for the antibody (“humoral”) immune response to clear HIV from the body. Indeed, the humoral immune response to HIV is very slow; for most viruses, neutralizing antibodies appear within days of infection. To help them design an effective HIV vaccine, scientists need to understand how the virus delays humoral responses to HIV infection (and how it later causes the production of HIV-specific antibodies to decline).
Although the depletion of gut-associated CD4+ T lymphocytes in early HIV-1 infection is well known, these results demonstrate the effects of early HIV-1 infection on gut-associated and circulating B lymphocytes. The findings of polyclonal B-cell activation and damage to gut-associated lymphoid follicles soon after HIV-1 infection may have implications for HIV-1 vaccine design. Specifically, an effective HIV-1 vaccine will need to ensure that significant levels of neutralizing antibodies are present in people before HIV-1 infection and that other protective immune defenses are fully primed so that, in the event of HIV-1 infection, the virus can be dealt with effectively before it disables any part of the immune system.