title: Expression of Fc epsilon receptors on activated human T lymphocytes.
abstract: Our results clearly demonstrate that the low-affinity receptor for IgE (Fc epsilon R) is an activation antigen transiently expressed on a subpopulation of human T lymphocytes. It can be selectively induced by stimulation with certain antigens or lectins, but it is not found on resting T cells. The increased numbers of activated Fc epsilon R+ T cells observed after stimulation of peripheral blood mononuclear cells (PBMC) from bee venom allergic patients with the specific allergen phospholipase A2 (PLA2) suggest that Fc epsilon R+ T cells might very well be involved in the regulation of the human IgE response against the respective antigen. These results were obtained by the use of two monoclonal antibodies, M-L25 and M-L47, which were raised against the human low-affinity Fc epsilon R in our laboratory. After stimulation of PBMC with phytohemagglutinin a peak of 7.6 +/- 6% Fc epsilon R+ T cells was observed on day 3, with pokeweed mitogen of 0.8 +/- 0.8% on days 2 and 3, and with concanavalin A of 0.6 +/- 0.7% Fc epsilon R+ T cells on day 2. Stimulation of PBMC with tetanus toxoid (TT) induced Fc epsilon R on maximally 0.6 +/- 0.8% of the total T cells (day 4), stimulation with purified protein derivative from tuberculin (PPD) on 0.2 +/- 0.6% of the T cells (day 2). In contrast to these antigens, stimulation of PBMC from bee venom allergic patients with PLA2 induced as a peak 2.5 +/- 2.5% of the total T cells to express Fc epsilon R (day 5), although the stimulated T cell population was much smaller than with TT or PPD, as was shown by their stimulation indices. The allergen-stimulated Fc epsilon R+ T cells were exclusively T4+. The Fc epsilon R-expression index was determined, which for a specific antigen or lectin correlates the percentage of Fc epsilon R+ T cells to the stimulated T cell population, respectively.
mesh_terms: D000485:Allergens / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D001514:Bee Venoms / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D006967:Hypersensitivity / Q000097:blood; D007073:Immunoglobulin E / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology / Q000648:ultrastructure; D010741:Phospholipases A / Q000276:immunology; D054467:Phospholipases A2; D011961:Receptors, Fc / Q000276:immunology / Q000502:physiology*; D017455:Receptors, IgE; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology / Q000648:ultrastructure*; D013745:Tetanus Toxoid / Q000276:immunology; D014373:Tuberculin / Q000276:immunology
chemical_list: D000485:Allergens; D000911:Antibodies, Monoclonal; D001514:Bee Venoms; D011961:Receptors, Fc; D017455:Receptors, IgE; D013745:Tetanus Toxoid; D014373:Tuberculin; D007073:Immunoglobulin E; D010741:Phospholipases A; D054467:Phospholipases A2