RANTES, a member of the C-C chemokine family, is a potent chemoattractant for T lymphocytes and eosinophils, but not neutrophils. To determine the effect of RANTES on cell recruitment in vivo, we injected up to 4 microg of RANTES intradermally into both allergic and nonallergic subjects and obtained biopsies 30 min, 6 h, and 24 h later. A dose- and time-dependent recruitment of eosinophils, CD45RO+ cells, and CD3+ cells was observed, with no effect seen on polymononuclear, cutaneous lymphocyte Ag+, CD68+, or tryptase+ cells. Eosinophil recruitment occurred more rapidly in allergic subjects than in nonallergic subjects. No eosinophil infiltrate was observed in nonallergic biopsies at 30 min and 6 h, whereas significant eosinophil recruitment was observed in allergic subjects by 30 min, reaching near-maximum levels by 6 h. The peak responses at 24 h were similar in both groups (nonallergic, 110 +/- 24 eosinophils/mm2; allergic, 113 +/- 38 eosinophils/mm2). The two groups had comparable numbers of circulating eosinophils. Major basic protein staining demonstrated eosinophil degranulation in both allergic and nonallergic groups. RANTES injection resulted in activation of endothelial E-selectin expression at 24 h. Incubation of cultured HUVECs with RANTES had no effect on adhesion molecule expression, suggesting that the in vivo effect may have been indirect. Our studies demonstrate that RANTES is a potent chemoattractant for eosinophils, CD3+ cells, and CD45RO+ cells in human skin. The accelerated eosinophil recruitment in allergic subjects provides support for the hypothesis that eosinophils from these subjects are primed in vivo.