EXPRESSION OF MONOCYTE CHEMOATTRACTANT PROTEIN-1 AND INTERLEUKIN-8 RECEPTORS ON SUBSETS OF T-CELLS - CORRELATION WITH TRANSENDOTHELIAL CHEMOTACTIC POTENTIAL

The differential expression of chemokine receptors may be an important mechanism for the regulation of T cell migration. To test this, we ex amined the expression and function of the monocyte chemoattractant pro tein (MCP)-1 and interleukin (IL)-8 receptors on various populations o f T cells. Using a simple and reliable transendothelial chemotaxis ass ay, both MCP-1 and IL-8 were shown to be chemotactic for subsets of bl ood T cells, although the relative response varied from donor to donor . To examine receptor expression and correlate it with chemotaxis of T cell subsets, monoclonal antibodies (mAb) to the receptors were produ ced by immunizing mice either with synthetic peptides (MCP-1 receptor) , or with receptor transfectants (IL-8 receptors A and B). A flow cyto metric analysis of blood T cells with an anti-MCP-1 receptor mAb revea led low expression on the CD26(hi) subset and undetectable expression on other T cells. Staining of T cells with anti-IL-8RA and anti-IL-8RB showed much higher levels of expression. but only on a subset of CD3( +) cells which were CD8(+) and CD56(+). That IL-8 and MCP-1 attracted distinct subsets of T cells was best illustrated using the CD26 marker , since IL-8R(+) T cells were CD26(-), whereas T cells expressing dete ctable MCP-1R or which responded to MCP-1 in chemotaxis assays were CD 26(hi). T cells activated in vitro with anti-CD3 up-regulated expressi on of the MCP-1 receptor, bur not the IL-8 receptors, and were attract ed to MCP-1 much more efficiently than resting T cells. These results show that there is a clear distinction between the IL-8- and MCP-1-res ponsive T cell populations and that chemokine receptor expression on T cells may be regulated with respect to lineage as well as cellular ac tivation.