Effect of lipoxygenase metabolites of arachidonic acid on proliferation of human T cells and T cell subsets

The lipoxygenase products LTB₄ and 15 HPETE have been reported to stimulate T suppressor cell function and also to inhibit [³H]thymidine incorporation into mitogen-stimulated T cells. This present report documents that although these compounds do indeed inhibit [³H]thymidine incorporation into unfractionated T cells, they significantly enhance [³H]thymidine incorporation into T cell preparation enriched for cells bearing the cytotoxic suppressor cell phenotype identified by the OKT8 monoclonal antibody. The mitogen response of T cells enriched for OKT4⁺ helper-inducer cells is inhibited in a manner similar to the response of unfractionated T cells. Thus, LTB₄ and 15 HPETE stimulate both the function and the proliferation of the cytotoxic-suppressor T cell subset.