Eight chemokines were tested for ability to elicit transendothelial chemotaxis of unstimulated peripheral blood T lymphocytes. The C-C chemokines monocyte chemotactic protein (MCP)-2, MCP-3, RANTES, macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, and, as previously described, MCP-1 induced significant, dose-dependent transendothelial chemotaxis of CD3(+) T lymphocytes. In contrast, the C-X-C chemokines interleukin-8 (IL-8) and interferon-gamma inducible protein-10 (IP-10) failed to induce transendothelial chemotaxis of CD3C(+) T lymphocytes or T lymphocyte subsets. RANTES, MIP-1 alpha, and MIP-1 beta induced significant transendothelial chemotaxis of CD4(+), CD8(+), and CD45R0(+) T lymphocyte subsets. Phenotyping of mononuclear cells that underwent transendothelial migration to MCP-2, MCP3, RANTES, or MIP-1 alpha showed both monocytes and activated (CD26 high), memory-type (CD45R0(+))T cells. Both CD4(+) and CD8(+) T lymphocytes were recruited, but not: natural killer cells or significant numbers of B cells. MCP-2 was the only C-C chemokine tested that attracted a significant number of naive-type (CD45RA(+))T lymphocytes. In the absence of endothelium, IL-8 but not IP-10 promoted modest but significant chemotoxis of CD3(+) T lymphocytes. Our data support the hypothesis that C-C, not the C-X-C chemokines IL-8 or IP-10, promote transendothelial chemotaxis of T lymphocytes.