The CC chemokine MIP-1 alpha induces a selective monocyte infiltration following intradermal injection into nonhuman primates

The in vitro chemotactic activity of chemokines have been well documented. However, study of their in vivo effects where components of rolling, adhere nce and diapedesis are pre-requisites to leukocyte infiltration have not be en examined in higher species. In this study, we examined the biological ac tivity of the CC chemokine, MIP-1 alpha, in rhesus monkeys. Following an in tradermal injection, a significant cellular infiltrate and an increase in t he number of inflamed vessels were observed. This response peaked at 24 h a nd was sustained for up to 48 hours after injection. Phenotypically, the sp ecific infiltrate consisted exclusively of CD68(+) monocytes with no increa se in other cell types over the saline injected controls. These studies rep resent the first examination of the in vivo effects of MTP-1 alpha in highe r species and indicate that MIP-1 alpha is a selective monocyte recruiting agent in vivo.