Expression of Qat-4 and Qat-5 alloantigens on cytotoxic precursor and effector cells: different surface phenotypes of alloreactive and H-2 restricted cytotoxic T cells

• Published in: European journal of immunology Vol. 12; no. 1; p. 43
• Main Authors: Zahn, G, Hämmerling, G J, Eichmann, K, Simon, M M
• Format: Journal Article
• Language: English
• Published: Germany 01.01.1982
• Subjects: Animals; Antibodies, Monoclonal - immunology; Antigen-Antibody Reactions; Antigens, Surface - genetics; Antigens, Surface - immunology; Cell Differentiation; Cells, Cultured; Complement System Proteins - metabolism; Cytotoxicity, Immunologic; Female; H-2 Antigens - genetics; H-2 Antigens - immunology; Immune Sera - pharmacology; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Phenotype; T-Lymphocytes - cytology; T-Lymphocytes - immunology
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830120110

Monoclonal anti-Qat-4 and anti-Qat-5 antibodies, which define antigens expressed on peripheral T cell subsets, have been used to study the phenotypes of alloreactive and H-2-restricted cytotoxic effector cells and their precursors. Depletion of Qat-4+ or Qat-5% cells from the T cell pool prior to their sensitization in bulk cultures prevented the development of alloreactive and H-2-restricted cytotoxic activities in the selected populations. No reconstitution of cytolytic activities to normal levels was obtained when mixtures of Qat-4- and Qat-5- cells were sensitized in bulk cultures to H-2 or non-H-2 antigens. Sensitization of limiting numbers of Qat-4- or Qat-5- lymphocytes under optimal conditions for help (interleukin 2), with the appropriated antigens (H-2 or H-Y) did not result in the generation of cytotoxic T cells, indicating that the majority of all cytotoxic T lymphocyte (CTL) precursors are Qat-4+, Qat-5+. When CTL effector populations were treated with the antisera and complement (C) at their maximum CTL activity, it was found that H-2-restricted CTL were totally eliminated by anti-Qat-4 and considerably reduced by anti-Qat-5 antisera and C. In contrast, alloreactive CTL effector cells were insensitive to anti-Qat-4 and to anti-Qat-5 plus C. Although alloreactive CTL effector populations regained some Qat-4 antigens during further in vitro culture, it was shown that H-2-restricted CTL were at all times more sensitive to anti-Qat-4 than were alloreactive CTL. The findings suggest that during maturation of alloreactive and H-2-restricted CTL from their precursors, both alloantigens undergo differential quantitative variations in their expression that lead to different Qat-4,5 phenotypes of alloreactive and H-2-restricted CTL.