title: Rapid changes in specificity within single clones of cytolytic effector cells.
abstract: We find rapid changes in the specificity of the cytolytic effector cells in a mixed lymphocyte culture. The lysis patterns produced by cytolytic effector cells generated near limiting dilution in murine mixed lymphocyte reactions of three types, F1 anti-parent (F1(A X B) anti-A), allogeneic (C anti-F1(A X B)), and F1 antimodified parent (F1(A X B) anti-A-TNP), were investigated. Cultures were characterized by their ability or inability to lyse a panel of target cells (e.g., A, B, F1). When individual cultures were tested at two different times, changes in lytic pattern were routinely seen, with some patterns reproducibly increasing in frequency and others reproducibly decreasing (e.g., patterns involving lysis of F1 decreased in an F1 anti-A response but increased in a C anti-F1 response). X-linked isoenzyme analysis showed that changes can occur within a single clone of effector cells. These results imply that the T cell specificity repertoire continues to evolve during an ongoing immune response, a conclusion incompatible with clonal selection theory.
authors.forename: J
authors.initials: J
authors.lastname: Reimann
authors.forename: R G
authors.initials: RG
authors.lastname: Miller
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002999:Clone Cells / Q000276:immunology; D005260:Female; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology; D007519:Isoantigens / Q000235:genetics / Q000276:immunology; D007527:Isoenzymes / Q000235:genetics; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010735:Phosphoglycerate Kinase / Q000235:genetics; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014960:X Chromosome
chemical_list: D006183:H-2 Antigens; D007519:Isoantigens; D007527:Isoenzymes; D010735:Phosphoglycerate Kinase