title: Antigen presentation in the rat: role of a nonadherent, nonphagocytic, W3/13, OX-6 positive T cell in the presentation of antigen to primed T lymphocytes.
abstract: The nature of accessory cells in rat lymph nodes which can present antigen to primed T cells was investigated. Removal of adherent, phagocytic cells from antigen-primed lymph node cells by passage over glass-bead and nylon wool columns followed by treatment with carbonyl iron did not abrogate the antigen-specific proliferative response to keyhole limpet hemocyanin (KLH) or to the synthetic polypeptide L-glutamic acid-L-alanine-L-tyrosine (GAT). This T cell-enriched population was free of contaminating macrophages as determined by latex bead ingestion and morphological criteria during a 4-day culture period. Treatment of the T cell preparation with rabbit anti-rat IgG and complement or rosetting with IgG-coated sheep erythrocytes to remove any remaining B cells or macrophages did not significantly affect the proliferative response to antigen. Analysis of the T cell preparation by panning techniques with monoclonal antibodies to T cell surface markers suggested that both the responding T cell and the antigen-presenting cell were positive for the rat T cell marker, W3/13. The KLH-primed LN T cell-enriched fraction contained two distinct cell populations that were separable on the basis of their reactivity to OX-6 antibody. Two populations, an OX-6+ and an OX-6-, interacted synergistically in a KLH-dependent in vitro proliferative response. The cells within the T cell-enriched fraction that were positive for the OX-6 marker functioned primarily as the APCs, while the OX-6- cell fraction contained cells that proliferated to antigen when OX-6+ cells from either the T cell fraction or the adherent fraction were present. The implications of these findings are discussed.
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology*; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology; D001402:B-Lymphocytes; D002469:Cell Separation; D000939:Epitopes; D006433:Hemocyanins / Q000276:immunology*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008264:Macrophages; D010641:Phenotype; D051381:Rats; D011912:Rats, Inbred ACI; D011916:Rats, Inbred F344; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology / Q000502:physiology
chemical_list: D000941:Antigens; D000954:Antigens, Surface; D000939:Epitopes; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin