Regulation of CCR5 and CXCR4 Expression by Type 1 and Type 2 Cytokines: CCR5 Expression Is Downregulated by IL-10 in CD4-Positive Lymphocytes

Abstract HIV-1 transmission and disease progression is, in general, characterized by initial predominance of macrophage tropic, non-syncytium-inducing strains followed by a switch to T-cell tropic, syncytium-inducing strains. Using sensitive, quantitative kinetic RT-PCR, we examined cytokine regulation of tropism-specific HIV-1 coreceptor expression in PBMCs from HIV-1-seronegative individuals. Proinflammatory (TNF-α and IL-12) and type 1 cytokines (IFN-γ and IL-2) significantly upregulated CCR5 (wt allele) mRNA expression in CCR5 homozygous wild-type (wt/wt) and heterozygous individuals (wt/del) ( P P P