Macrophage tropism of HIV-1.

Both in vivo and in vitro studies clearly demonstrate that cells of the mononuclear phagocyte lineage are major hosts for human immunodeficiency virus type 1 (HIV-1) replication. Presumably these cells play a key role in the pathogenesis of acquired immunodeficiency syndrome (AIDS). To further delineate the interactions between HIV-1 and host cells, the susceptibility and permissivity of normal human peripheral blood-derived monocyte/macrophages (M/M) and T lymphocytes, and neoplastic monocytoid and lymphoid cell lines to various HIV-1 isolates was assessed. The results suggest: (1) "fresh" isolates recovered from patients and propagated only in normal host cells exhibit a dual tropism for both M/M and T cells, regardless of their tissue of origin or the cell type from which they were isolated; (2) the repeated passage of an HIV-1 isolate through normal M/M does not generally result in the loss of the ability to infect normal T cells nor vice versa; (3) the majority of fresh HIV-1 isolates do not infect neoplastic cells of either origin, and those that do show no preference for monocytoid or lymphoid targets, regardless of their cell origin.