Acquisition of HIV type 1 resistance by β-chemokine-producing CD4⁺ T cells

The CD4⁺ T cell is a major target cell type for human immunodeficiency virus type 1 (HIV-1) infection, in this study, we provide evidence that the susceptibility to HIV-1 infection is variable in individual CD4⁺ T cells. Five CD4⁺ T cell clones were isolated from an HIV-1-seronegative donor and were investigated for their susceptibility to HIV-1 infection. Four CD4⁺ T cell clones were resistant to infection by a macrophage-tropic (R5) HIV-1 isolate whereas one clone was fully permissive. The level of susceptibility to HIV-1 correlated inversely with β-chemokine production, including RANTES (regulated on activation, normally T cell expressed and secreted), macrophage inflammatory protein 1α (MIP-1α), and MIP-1β. Resistance to HIV-1 infection was abrogated by the combined use of neutralizing antibodies against these three β-chemokines. Interestingly, a complete inhibition of HIV-1 infection was observed in peripheral blood mononuclear cells on infection induced by adding the culture supernatant or a small number of HIV, 1-resistant cell clones. Our results suggest the presence of a clonal self- defense mechanism within the CD4⁺ T cell population in vivo that involves the secretion of β-chemokines.