CD8(-BLOOD LYMPHOCYTES ARE POTENT SOURCES OF MACROPHAGE INFLAMMATORY PROTEIN 1-ALPHA, INTERLEUKIN-8 AND RANTES() AND CD45RA(+) HUMAN PERIPHERAL)

The chemokines macrophage inflammatory protein 1 alpha. (MIP 1 alpha), interleukin-8 (IL-8) and RANTES are potent regulators of leukocyte tr afficking. Examination of chemokine secretion by human peripheral bloo d lymphocytes after stimulation with anti-CD3 or phorbol 12, 13 myrist ate acetate and ionomycin showed CD8(+) cells were the dominant source of MIP 1 alpha and RANTES. Although production of MLP 1 alpha and IL- 8 were similar in pharmacologically stimulated CD4(+) CD45RA(+), CD4() CD45RO(+), and CD8(+) CD45RA(+) cells, the largest amounts of MIP 1 alpha and RANTES were secreted by CD8(+) CD45RO(+) lymphocytes. A para llel pattern of prolonged chemokine mRNA expression for at least 18 h after activation was observed in the T cell subsets. These results con firm that human T lymphocytes have a unique capacity for secretion of these three chemokines. In addition, CD8(+) cells have an unrecognized role in recruiting cells to sites of inflammation, and adult human CD 45RA(+) cells have a physiologically significant secretory capacity.