CD8+ T cell suppressor factors and the control of infection, replication and transcription of human immunodeficiency virus.

CD8+ T cells have been shown to produce factors which modulate HIV-1 replication in both T cells and monocytic cells. Examination of the literature reveals that this modulation may occur by the production of beta-chemokines which block viral entry. However, another CD8+ T cell-derived factor(s) targets the replication of HIV-1 at the level of transcription. CD8+ T cell factors strongly suppress replication at the level of transcription in T cells and T cell lines, the factors enhance both replication and transcription in cells of the monocyte/macrophage lineage. The enhancement of transcription and replication, which is pertussis toxin sensitive is induced by increased production of TNF-alpha by the target cells. Thus, CD8+ T cells produce factors which mediate effects on transcription and replication of HIV-1 in a cell type-dependent manner. In this review a summary of the effects of chemokines and CD8-derived factors on HIV-1 transcription and replication is presented focusing on the cellular pathways which may mediate their effects on HIV transcription and replication in different cell types. The virus-host cell interactions that participate in the persistent replication of HIV in macrophages and the suppression of these functions in T cells require definition. The identification of CD8+ T cell factors which exert these controls on HIV-1 may lead to promising new therapies for HIV infection.