CXCR4 and CCR5 expression on CD4(+) T cells in vivo and HIV-1 antigen beta-chemokine production in vitro after treatment with HIV-1 immunogen (REMUNE)

Background: The chemokine receptors CXCR4 and CCR5 have been identified as the major coreceptors for HIV-1 on CD-IC cells and macrophages. The natural ligands for these receptors are SDF-1 and the beta-chemokines (MIP-1 alpha . MIP-I beta, RANTES), respectively, and are the products of a variety of i mmune cells, including CD8(+) T lymphocytes. Study Design/Methods: We hypothesized that the ability to stimulate the nat ural ligands for these receptors using an immune based therapy might influe nce in vivo chemokine receptor expression. Results: In vivo CXCR4 expression remained stable after treat-ment with an HIV-1 Immunogen (REMUNE), whereas CCR5 expression on CD4(+) T cells decreas ed (p < .05). Furthermore, HIV-1 antigen-specific production of beta-chemok ines in vitro was also augmented (P < .05). Conclusions: These preliminary results suggest that this HIV-1-specific imm une-based therapy carl stimulate antigen-specific beta-chemokine production in vitro and downregulate CCR5 receptor expression on CD4 cells in vivo.