Differential effects of human immunodeficiency virus isolates on β- chemokine and gamma interferon production and on cell proliferation

All human immunodeficiency virus (HIV) isolates can grow readily in primary CD4⁺ T cells, but they can be distinguished by their ability to replicate in macrophages and established T-cell lines. The macrophagetropic viruses are generally non-syncytium inducing (NSI), whereas the T-cell-line- tropic viruses are syncytium inducing (SI) in cultured cells. We now demonstrate that infection of CD4⁺ T cells by NSI and SI viruses shows a differential effect on production of β-chemokines and gamma interferon. Infection by NSI viruses increased production of MIP-1α, MIP-1β, and gamma interferon, whereas infection by SI viruses had no effect or decreased production of these cytokines. Production of RANTES was slightly increased during infection by both virus phenotypes. This differential effect of NSI and SI viruses was observed at the level of β-chemokine mRNA as well as at the level of protein expression. Infection by NSI viruses also increased CD4⁺ cell proliferation. These results may have relevance for a differential role of HIV strains in AIDS pathogenesis.