INTERFERON-GAMMA INCREASES EXPRESSION OF CHEMOKINE RECEPTORS CCR1, CCR3, AND CCR5, BUT NOT CXCR4 IN MONOCYTOID U937 CELLS

Chemokine receptors (CR), which can mediate migration of immune cells to the site of inflammation, also function as coreceptors for human im munodeficiency virus (HIV) entry into CD4(+) T lymphocytes and antigen -presenting cells. We demonstrate here that interferon-gamma (IFN-gamm a) increases the expression of chemokine receptors CCR1, CCR3, and CCR 5 in monocytoid U937 cells as detected by cell surface molecule labeli ng and mRNA expression, as well as by intracellular calcium mobilizati on and cell migration in response to specific ligands. The increased e xpression of these chemokine receptors also results in an enhanced HIV -1 entry into cells. Our data provide evidence for a relationship of c ellular pathways that are induced by IFN-gamma with those that regulat e chemokine receptor expression. (C) 1998 by The American Society of H ematology.