SDF-1α Is a Potent Inducer of HIV-1-Specific CD8+ T-Cell Chemotaxis, But Migration of CD8+ T Cells Is Impaired at High Viral Loads

Abstract Multiple impairments in HIV-1-specific cytotoxic T cells (CTL) have been reported, but derangements in HIV-1-specific CD8+ T-cell chemotaxis have not been described previously. We assessed migration to SDF-1α (stromal cell-derived factor 1-alpha) and CX3CL1 in vitro and expression of cognate receptors, CXCR4 and CX3CR1, by flow cytometry in peripheral blood and lymph node CD8+ T cells from HIV-1-seropositive and -seronegative individuals. Compared with seronegative individuals, percentages of CXCR4+ CD8+ T cells were reduced (median, 26% versus 74%, p < 0.001) and percentages of CX3CR1+CD8+ T cells were increased (median, 33% versus 15%, p = 0.03) in seropositive individuals. Robust migration of peripheral blood mononuclear cell (PBMC) CD8+ T cells to SDF-1α (1 μg/ml) was observed in both HIV-1-seropositive (median chemotactic index [CI] 4.9) and -seronegative (median CI 2.8) subjects (p = 0.46). CI to SDF-1α was not significantly related to percentage of CXCR4+ CD8+ T cells or density of CXCR4, ...