Productive and lytic infection of human CD4+ type 1 helper T cells with macrophage-tropic human immunodeficiency virus type 1.

It is generally recognized that macrophage-tropic human immunodeficiency virus type I (HIV-1) is the predominant population during the acute and asymptomatic phases of HIV-1 infection. Here, we compared the proliferation and syncytium-inducing activities of different HIV-1 strains in primary CD4(+) T cells expressing various helper T (Th) type cytokine profiles. The macrophage-tropic HIV-1 strains HIV-1(JR-CSF), HIV-1(NFN-SX), and HIV-1(SF162) could proliferate vigorously and generate syncytia in primary CD4(+) T cells irrespective of their Th subtype, in contrast to the T-cell-line-tropic HIV-1 strains HIV-1(NL4-3) and HIV-1(IIIB), which favored non-type 1 Th conditions. These results indicate that macrophage-tropic HIV-1 may be more invasive and virulent, since it kills more CD4(+) Th1 cells than T-cell-line-tropic HIV-1 during the early stages of HIV-1 infection, when the Th1 immune response is dominant.