Attenuation of HIV-1 infection by other microbial agents.

Although potentiation of human immunodeficiency virus (HIV) type 1 (HIV-1) infection has been known to occur in coinfection with a variety of pathogens and types of vaccination, there are emerging data on specific infectious agents that may attenuate HIV-1 infection. New literature suggests that certain pathogens are capable of inhibiting HIV-1 replication. These include GB virus C, measles virus, Orientia tsutsugamushi, and human T lymphotropic virus types 1 and 2. In addition, there are conflicting data on the effects of Mycobacterium tuberculosis on the replication of HIV-1, with some suggesting that this organism may inhibit HIV-1 replication. Also remaining controversial are the possible protective effects of HIV type 2 against HIV-1 infection. In this review, we summarize and critically discuss the body of emerging literature concerning infections that may have the ability to attenuate HIV-1 infection.