Chemokine Receptor‐Usage of Clinical HIV‐1 Isolates Obtained from Patients with HIV‐1 Infection in Late Clinical Stages Using PHA‐Blast

AbstractIn the present sudy, chemokine receptor‐usage of primary HIV‐1 isolates was examined using U87‐CD4 cells expressing chemokine receptors CCR3, CCR5 and CXCR4. HIV‐1 was isolated from the peripheral blood mononuclear cells (PBMC) and/or plasma of eight HIV‐1‐infected individuals in late CDC‐II and CDC‐IV clinical stages using PHA‐blast prepared from the PBMC of healthy blood donors. The primary HIV‐1 isolates from patients in late CDC‐II stage rarely infected monocyte‐derived macrophages in the present study, whereas most isolates from patients in the CDC‐IV stage infected the macrophages. In the experiments using U87‐CD4 cells expressing chemokine receptors, the isolates from patients in the late CDC‐II stage infected U87‐CD4 cells expressing CXCR4, but not U87‐CD4 cells expressing CCR5. In contrast, most isolates from patients in the CDC‐IV stage infected both U87‐CD4 cells expressing CXCR4 or CCR5. The isolates which infected both U87‐CD4 cells were supposed to contain dual tropic HIV‐1 or a mixture of CXCR4‐tropic and CCR5‐tropic HIV‐1s. Analysis of the deduced amino acid sequence of the V3 region in proviral env gene showed that the V3 region in U87‐CD4 cells infected with CXCR4‐tropic HIV‐1 isolates was largely different from that in the cells infected with CCR5‐tropic isolates, but were highly similar to that in cells infected with dual tropic isolates. These results suggest that PHA‐blasts may preferentially support the replication of the CXCR4‐tropic and dual tropic HIV‐1s, and that CXCR4‐tropic and dual tropic HIV‐1s are also present in peripheral blood from patients in the late stage of the asymptomatic phase.