C-C chemokines in allergen-induced late-phase cutaneous responses in atopic subjects: Association of eotaxin with early 6-hour eosinophils, and of eotaxin-2 and monocyte chemoattractant protein-4 with the later 24-hour tissue eosinophilia, and relationship to basophils and other C-C chemokines (Monocyte chemoattractant protein-3 and RANTES)

The relationship of expression of the C-C chemokines eotaxin, eotaxin 2, RA NTES, monocyte chemoattractant protein-3 (MCP-3), and MCP-4 to the kinetics of infiltrating eosinophils, basophils, and other inflammatory cells was e xamined in allergen-induced, late-phase allergic reactions in the skin of h uman atopic subjects. EG2(+) eosinophils peaked at 6 h and correlated signi ficantly with eotaxin mRNA and protein, whereas declining eosinophils at 24 h correlated significantly with eotaxin-2 and MCP-4 mRNA. In contrast, no significant correlations were observed between BB1(+) basophil infiltrates, which peaked at 24 h, and expression of eotaxin, eotaxin-2, RANTES, MCP-3, and MCP-4 or elastase(+) neutrophils (6-h peak), CD3(+) and CD4(+) T cells (24 h), and CD68(+) macrophages (72 h). Furthermore, 83% of eosinophils, 4 0% of basophils, and 1% of CD3(+) cells expressed the eotaxin receptor CCR3 , while eotaxin protein was expressed by 43% of macrophages, 81% of endothe lial cells, and 6% of T cells (6%). These data suggest that 1) eotaxin has a role in the early 6-h recruitment of eosinophils, while eotaxin-2 and MCP -4 appear to be involved in later 24-h infiltration of these CCR3(+) cells; 2) different mechanisms may guide the early vs late eosinophilia; and 3) o ther chemokines and receptors may be involved in basophil accumulation of a llergic tissue reactions in human skin.