The role of class II MHC molecules in the activation of class I-reactive T cell hybridomas.
To examine the role of Ia molecules in T cell responses to allo-class I major histocompatibility antigens, a series of allo-class I-reactive T cell hybridomas was established. Of 134 T cell hybridomas obtained from the fusion of C3H/HeJm or B10.HTT T cells stimulated with C57BL/6 splenocytes, nine T cell hybridomas were reactive to class I antigens and 126 T cell hybridomas were reactive to class II antigens. Six of the nine IL 2-producing T cell hybridomas were further analyzed: five mapped to H-2Kb and the other mapped to H-2Db. Three of these T cell hybridomas, HTB-157.7, HTB-176.10, and HTB-177.2, could react to the EL-4 cell line that expresses H-2Kb and H-2Db class I antigens but lacks class II I-Ab molecules. Furthermore, the activation of these three T cell hybridomas with C57BL/6-derived splenocytes was not blocked by either anti-I-A or anti-L3T4 antibody. In contrast, the other three T cell hybridomas, CB-127.6, CB-221.7, and HTB-102.7, failed to react with EL-4 but reacted with the LB cell line which expresses class I (H-2Kb, H-2Db) and class II (I-Ab) molecules. Although class II molecules were required for activation of the latter clones, there was no apparent I-A allele specificity, suggesting that a relatively nonpolymorphic Ia determinant was involved. The activation of the three latter T cell hybridoma clones with C57BL/6 splenocytes could be blocked completely by either anti-I-A or anti-L3T4 antibody. The data are interpreted in terms of possible T cell receptor models for recognition of class I with nonpolymorphic class II determinants.
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Minami
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Nariuchi
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Kawasaki
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Dorf
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D002460:Cell Line; D000939:Epitopes; D006183:H-2 Antigens / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II