C-C chemokine profile of cord blood mononuclear cells: selective defect inRANTES production

Three C-C chemokines inhibit human immunodeficiency virus (HIV) entry into macrophages: macrophage inflammatory protein-1 alpha (MIP-1 alpha), MIP-1 b eta, and regulated-upon activation, normal T-cell expressed and secreted (R ANTES), We studied the ability of placental cord blood mononuclear cells (C BMC) to secrete these C-C chemokines in comparison to adult blood mononucle ar cells (ABMC), CBMC had diminished ability to secrete RANTES, as determin ed by enzyme-linked immunosorbent assay. Secretion of MIP-1 alpha and MIP-1 beta were similar in CBMC and ABMC, Whereas MIP-1 alpha and MIP-1 beta sec retion were comparable in monocytes and lymphocytes, RANTES was secreted pr imarily by lymphocytes. Flow cytometric analysis of RANTES expression showe d diminished intracellular RANTES expression in cord blood lymphocytes (CBL ) compared to adult (peripheral) blood lymphocytes (ABL), A subset analysis of RANTES-producing CBL and ABL demonstrated that RANTES was produced pred ominantly by CD8+/CD45RO+ cells. CBL had a reduced proportion of CD8+/CD45R O+ cells compared with ABL, which may account for the diminished RANTES sec retion by CBMC, These results may be relevant to the pathogenesis of perina tal HIV infection.