title: Quantification of antigen-reactive cells among human T lymphocytes.
abstract: The number of antigen-reactive cells among human peripheral blood T lymphocytes was estimated by a limiting dilution analysis. Antigen-induced lymphocyte activation was measured by means of incorporation of tritiated thymidine [3H]dThd. We have studied the frequency of memory T cells for the bacterial antigens tuberculin PPD and tetanus toxoid in immune donors, as well as the frequency of alloantigen-reactive T cells. In 11 different donors, the observed frequencies of the antigen-reactive T cell ranged between 1:300 and 1:16 000 for PPD; for tetanus toxoid values, between 1:750 and 1:11 500 were obtained in 5 different donors. The frequency of alloantigen-reactive T cells was found to be higher: between 1:200 and 1:600 (n = 10). For 3 donors, the estimated frequencies proved to be reproducible over a period of several months. Finally, a correlation could be demonstrated between the frequency of PPD-reactive T cells and the [3H]dThd incorporation of 4 X 10(4) PPD-stimulated lymphocytes.
mesh_terms: D000942:Antigens, Bacterial; D001772:Blood Cell Count; D002478:Cells, Cultured; D000939:Epitopes; D006801:Humans; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D013601:T-Lymphocytes / Q000276:immunology; D014373:Tuberculin
chemical_list: D000942:Antigens, Bacterial; D000939:Epitopes; D014373:Tuberculin