Regulation of human monocyte HLA-DR and CD4 antigen expression, and antigen presentation by 1,25-dihydroxyvitamin D3

摘要: 1,25-Dihydroxyvitamin D3 (1,25(OH)2-D) has been shown to be a macrophage-derived cytokine, capable of regulating myeloid differentiation and T-cell activation in vitro. Therefore, we examined the effects 1,25(OH)2-D on monocyte phenotype function human peripheral blood monocytes as an index its biologic role at inflammatory site. treatment consistently specifically reduced HLA-DR CD4 expression by monocytes, while CD14 class I HLA antigen were unaffected. Expression Fc gamma R I-III was variably modulated treatment, but no differences antibody-dependent cell cytotoxicity (ADCC) observed, measured using either ADCC or anti-Fc R-antibody expressing hybridomas. In contrast, ability induce antigen-dependent proliferation markedly pretreatment for little 6 hours. Addition interleukin-1 (IL-1), IL-6, indomethacin did not restore proliferation, suggesting that this observation secondary changes IL-1, PGE2 production induced 1,25(OH)2-D. These data suggest modulates function, altering presentation, leaving lytic intact. findings may relevant immunobiologic