Recognition of leukotriene B4 by a unique subset of human T-lymphocytes

Abstract

Leukotriene (LT) B4, but not 12(S)-LTB4 or LTC4, inhibits the generation of lymphokine-designated leukocyte inhibitory factor by purified human T-lymphocytes. LTB4 coupled to fluorescein-labeled human serum albumin interacts specifically with approximately 11% of the T-lymphocytes as assessed by fluorescence-activated flow cytometry. The LTB4-reactive T-lymphocytes are distributed between the suppressor-cytotoxic (14%) and helper-inducer (8%) subsets, which were identified concurrently by phycoerythrin-labeled monoclonal antibodies to subset-specific antigens. LTB4, but not 12(S)-LTB4 or LTC4, significantly enhances the proliferation of mitogen-stimulated purified suppressor-cytotoxic T-lymphocytes at concentrations of 10(-12)M to 10(-6)M and significantly inhibits the proliferation of mitogen-stimulated purified helper-inducer T-lymphocytes at concentrations of 10(-8)M to 10(-6)M, as assessed by the uptake of [3H]thymidine. The net effect of LTB4 on blood T-lymphocytes is immunosuppression that may be expressed in some human hypersensitivity and inflammatory diseases.