title: T cell-mediated recognition of foreign antigen and the Ia molecule observed by stopped-flow fluorometry.
abstract: Th cell-mediated rapid recognition of foreign Ag and the Ia molecule was studied using azobenzenearsonate-L-tyrosine (ABA-L-tyrosine)-specific Th cells (I-Ak restricted), foreign Ag (ABA-L-tyrosine), and APC (H-2k). Initial transmembrane signals in Th cell hybridomas (2-45-12) and in Th cell lines (A24-17 or A33-7) were monitored by stopped-flow fluorometry with fluorescent probes. It was found that Th cells recognized foreign Ag within 1 s at 25 degrees C on the APC (B10.BR spleen cells or L cells into which I-Ak genes were transferred). Recognition of foreign Ag and the Ia molecule was shown to deliver the initial signals to Th cell hybridomas and T cell lines. First, Th cells had membrane fluidity increased and then calcium was transported from the external medium into the T cells. The initial transmembrane signals to Th cell hybridomas were inhibited by the addition of an anti-I-Ak mAb. None of the initial signals were observed in the absence of either specific foreign Ag or APC.
authors: Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
authors: N
authors: N
authors: Utsunomiya
authors: M
authors: M
authors: Nakanishi
authors: Y
authors: Y
authors: Arata
authors: T
authors: T
authors: Yasuda
authors: S
authors: S
authors: Saito
authors: K
authors: K
authors: Koyama
authors: T
authors: T
authors: Tadakuma
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001391:Azo Compounds / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D005434:Flow Cytometry / Q000379:methods; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology / Q000378:metabolism; D007473:Ion Channels; D008560:Membrane Fluidity; D051379:Mice; D008806:Mice, Inbred AKR; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000276:immunology; D010132:p-Azobenzenearsonate / Q000031:analogs & derivatives / Q000276:immunology*
chemical_list: D001391:Azo Compounds; D000949:Histocompatibility Antigens Class II; D007473:Ion Channels; C000234:azobenzenearsonate-N-acetyl-L-tyrosine; D014443:Tyrosine; D010132:p-Azobenzenearsonate; D002118:Calcium