Characterization of a CD4(L3T4)-positive cytotoxic T cell clone that is restricted by class I major histocompatibility complex antigen on FBL-3 tumor cell.
An L3T4(CD4)+ CTL clone specific for Friend virus-induced tumor FBL-3 was isolated, characterized and compared with a conventional Lyt-2(CD8)+ CTL clone. This clone L3.1 was obtained from the limiting dilution culture of splenic MLTC cells from a CB6F1 mouse whose CD8+ T cells had been suppressed by an in vivo injection of anti-Lyt-2.2 mAb. The phenotype of clone L3.1 was sIg-, Thy-1.2+, L3T4(CD4)+, Lyt-2 (CD8)-, and Ia- as determined by flow-cytometry. Northern blot analysis also confirmed that mRNA for L3T4(CD4), but not for Lyt-2 (CD8) was present in the total RNA of L3.1. The FBL-3-specific killing activity of L3.1 was inhibited by anti-H-2D6 mAb, and the tumor cells did not express class II MHC antigen, indicating that the recognition of tumor antigen by this CD4+ CTL clone was restricted by the class I MHC molecule on the tumor cells. Furthermore, the finding that anti-L3T4(CD4) mAb GK1.5 inhibited the specific and lectin-dependent non-specific cytotoxicity of L3.1 suggested that CD4 molecules on this CTL clone are not ligand (MHC class II)-binding proteins, but are involved in signal transduction.
Matsubayashi
Y
Y
Institute of Immunology, Faculty of Medicine, Kyoto University, Japan.
Zenita
K
K
Morioka
A
A
Iwashiro
M
M
Masuda
T
T
Uchino
H
H
Fujita
T
T
Kuribayashi
K
K
D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis / Q000276:immunology* / Q000502:physiology; D000951:Antigens, Neoplasm / Q000276:immunology*; D015704:CD4 Antigens / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000502:physiology; D016827:CD8 Antigens; D002999:Clone Cells; D003601:Cytotoxicity Tests, Immunologic; D000939:Epitopes; D005622:Friend murine leukemia virus; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000502:physiology; D037102:Lectins; D007942:Leukemia, Experimental / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010641:Phenotype; D012333:RNA, Messenger / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000951:Antigens, Neoplasm; D015704:CD4 Antigens; D016827:CD8 Antigens; D000939:Epitopes; D015395:Histocompatibility Antigens Class I; D037102:Lectins; D012333:RNA, Messenger