C-C chemokine profile of cord blood mononuclear cells: selective defect in RANTES production.

Three C-C chemokines inhibit human immunodeficiency virus (HIV) entry into macrophages: macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and regulated-upon activation, normal T-cell expressed and secreted (RANTES). We studied the ability of placental cord blood mononuclear cells (CBMC) to secrete these C-C chemokines in comparison to adult blood mononuclear cells (ABMC). CBMC had diminished ability to secrete RANTES, as determined by enzyme-linked immunosorbent assay. Secretion of MIP-1alpha and MIP-1beta were similar in CBMC and ABMC. Whereas MIP-1alpha and MIP-1beta secretion were comparable in monocytes and lymphocytes, RANTES was secreted primarily by lymphocytes. Flow cytometric analysis of RANTES expression showed 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 predominantly by CD8+/CD45RO+ cells. CBL had a reduced proportion of CD8+/CD45RO+ cells compared with ABL, which may account for the diminished RANTES secretion by CBMC. These results may be relevant to the pathogenesis of perinatal HIV infection. (Blood. 2000;95:715-718)