title: In vitro immunization to KLH. II. Limiting dilution analysis of antigen-reactive cells in primary and secondary culture.
abstract: Limiting dilution analysis was used to estimate the frequency of human peripheral blood T lymphocytes that proliferate in response to in vitro immunization with keyhole limpet hemocyanin (KLH). Antigen-reactive cells (ARC) were estimated 9 days after primary immunization with KLH. The ARC frequency of lymphocytes from 12 subjects ranged from 1:23,800 to 1:52,631. Lymphocytes from five of these subjects were also primed for 12 days with KLH, rechallenged in secondary culture with fresh adherent cells and KLH, and assayed 4 days later. The ARC frequency increased to 1:1,123 to 1:7,247, indicating that T cell clones responsive to KLH had expanded during primary culture. In addition, we observed that the proliferative response of lymphocytes from 5 of the 12 subjects were inhibited at high cell concentrations. Depletion of OKT8+ T cells before culturing with KLH however did not alter the inhibitory effect of high concentrations of T cells.
mesh_terms: D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes; D005802:Genes, MHC Class II; D006433:Hemocyanins / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000939:Epitopes; D011948:Receptors, Antigen, T-Cell; D006433:Hemocyanins