title: Characterization of a product of histoincompatible spleen cells restoring class I-inhibited mixed-lymphocyte culture reactions.
abstract: Conditions leading to the formation of a recognition product (SEPIR) capable of restoring MLC responses inhibited by treating stimulator cells with mAb to Class I antigens have been investigated. SEPIR has been found to be present in supernatants of immunological one-way interactions of histoincompatible spleen lymphocytes from naive mice following cultivation for a few hours. It is active in relatively high dilutions. Similarities with cytokines of IL-1, IL-2, or interferon character could not be revealed. Formation of the heat-labile principle is governed by immunologically specific reactions and involves recognition of Class I (but not Class II) HMC antigens by T cells of Lyt-2 phenotype. B cells and Lyt-1+ cells failed to induce formation of the product. SEPIR appears to be a complex of T-cell receptors for Class I antigens with these antigens. The data indicate that in conventionally induced fully incompatible MLC responses a similar product might be formed.
mesh_terms: D000818:Animals; D006183:H-2 Antigens / Q000276:immunology* / Q000302:isolation & purification; D006648:Histocompatibility; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology; D008819:Mice, Nude / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology* / Q000302:isolation & purification; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000032:analysis / Q000276:immunology*
chemical_list: D006183:H-2 Antigens; D011948:Receptors, Antigen, T-Cell