Interleukin 13 and interleukin 4 protect bronchoalveolar macrophages from productive infection with human...

In this study, we examined the impact of the predominantly Th2-type lymphokines interleukin 13 (IL-13) and interleukin 4 (IL-4) on acute infection of human bronchoalveolar macrophages with a macrophage-tropic isolate of human immunodeficiency virus type 1 (HIV-1). Addition of 0.01-10 ng of IL-4 or IL-13 per milliliters significantly blocked HIV-1 replication in infected cells, judging from levels of reverse transcriptase and p24 antigen in the supernatants of infected cells. Both IL-4 and IL-13 were almost as efficient as interferon-gamma (IFN-gamma) in preventing HIV-1 replication, when given in equivalent amounts. Moreover, neither IL-13 nor IL-4 interfered with the IFN-gamma-mediated enhancement of anti-HIV-1 activity in alveolar macrophages. Both IL-4 and IL-13 interfered with enhanced replication of HIV-1 in macrophages pulsed with the growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). Interleukin 13 also prevented HIV-1 release from peripheral blood mononuclear cells in a cocultivation experiment with feeder cells from a seronegative subject. These data suggest that Th2-derived lymphokines have significant anti-HIV-1 activity in cells of the macrophage lineage, although they may enhance the susceptibility of HIV-1-infected subjects to some opportunistic pathogens.