Relationship between T cell receptors and antigen-binding factors. II. Common antigenic determinants and epitope recognition shared by T cell receptors and antigen-binding factors.
The T cell hybridomas 231F1 and 12H5 constitutively secrete glycosylation-inhibiting factor (GIF) and glycosylation-enhancing factor (GEF), respectively, which lack affinity for OVA-coupled Sepharose. When the 231F1 and 12H5 cells were stimulated by OVA-pulsed syngeneic macrophages, however, GIF and GEF produced by the cells had affinity for OVA. Both the OVA-binding GIF from the 231F1 cells and OVA-binding GEF from the 12H5 cells bound to a mAb against TCR-alpha beta and a mAb against TCR-alpha, suggesting a serologic relationship between TCR and OVA-binding factors. However, the OVA-binding GIF and GEF bound to mAb 14-12 and 14-30, respectively. Because these mAb do not bind TcR alpha beta-chains, it appears that the Ag-binding factors are different from TCR itself. The OVA-binding factors from both 12H5 cells and 231F1 cells do not bind to urea-denatured OVA. The binding of the factors to OVA Sepharose was inhibited by a peptide corresponding to residues 307-317 (P307-317) in the native OVA, but not by the peptide corresponding to residues 323-339 (P323-339). Furthermore, the OVA-binding factors bound to P306-319-coupled Sepharose but not to P323-339-coupled Sepharose, and were recovered by elution of the former Sepharose at acid pH. The binding of OVA to anti-OVA antibodies was not inhibited by either peptide. Inasmuch as the 231F1 cells and 12H5 cells can be stimulated by P307-317 in the context of a MHC product, it appears that the Ag-binding factors and TCR-alpha beta on the cell sources of the factors may recognize the same epitope in the OVA molecules. The results also showed that Ag-binding factors and antibodies recognize distinct epitopes in the Ag molecules.
Iwata
M
M
Johns Hopkins University School of Medicine, Good Samaritan Hospital, Baltimore, MD 21239.
Katamura
K
K
Kubo
R T
RT
Grey
H M
HM
Ishizaka
K
K
D000818:Animals; D001666:Binding Sites, Antibody; D002460:Cell Line; D000939:Epitopes / Q000032:analysis* / Q000276:immunology; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008222:Lymphokines / Q000032:analysis* / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology / Q000378:metabolism; D029584:Prostatic Secretory Proteins; D011948:Receptors, Antigen, T-Cell / Q000032:analysis* / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism*
D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; D011948:Receptors, Antigen, T-Cell; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D010047:Ovalbumin