Modulation of IL‐8 receptor expression on purified human T lymphocytes is associated with changed chemotactic responses to IL‐8

Interleukin‐8 is a member of the chemokine superfamily and is a major mediator of acute inflammation. Although IL‐8 has been reported by some laboratories also to be a chemoattractant for T lymphocytes, this has been difficult to confirm and remains a controversial issue. By using freshly purified human T cells (90–95% CD3 + ), we could demonstrate consistent directional migration of T cells to recombinant human IL‐8. IL‐8 was as potent as RANTES, MIP1 α , and M1P1 β in inducing T cell chemotaxis. Highly purified T cells, however, incubated at 37° for more than 12 h or cultured over‐night with anti‐CD3 antibody cross‐linked to plastic dishes, showed a markedly reduced capacity to migrate in response to IL‐8. This was associated with a decrease in binding of radioiodinated IL‐8 to T cells. Northern blot and polymerase chain reaction analyses showed that freshly purified T cells expressed mRNA for both IL‐8 receptor type A and type B. Steady‐state levels of mRNA for the IL‐8RA and IL‐8RB genes were also reduced by incubation of the cells with or without anti‐CD3 for 12 h at 37°. These results indicate that T cells are indeed one of the target cell populations for IL‐8. The regulation of IL‐8 receptor expression on T lymphocytes may contribute to the pathophysiological role of IL‐8 in inducing the homing and infiltration of T cells. J. Leukoc. Biol. 57: 335–342; 1995.