title: Dissociation of Fas-mediated cytotoxicity and FasL expression in a cytotoxic CD4+ T-cell clone. Comparative analysis of Fas-mediated cytotoxicity between a T-hybridoma and a T-cell clone.
abstract: Fas-mediated cytotoxicity or activation-induced cell death (AICD) were analyzed and compared between a CD4+ cytotoxic T-cell clone (DB14) and a T-hybridoma (DBhy22) both of which bear the same T-cell antigen receptor (TCR) specific for p43-58 and restricted to I-Ab/d. DBhy22 expressed detectable FasL mRNA 4 h after activation through TCR and the expression of FasL mRNA reached a peak after 8 h of activation. The expression level of FasL mRNA was clearly associated with the level of Fas-mediated cytotoxicity and AICD seen after activation. On the other hand, FasL mRNA and FasL molecules were constitutively expressed in DB14 irrespective of the activation state. However, DB14 exhibited the Fas-mediated cytotoxicity only after activation. The present study suggests that Fas-mediated cytotoxicity requires not only FasL expression but also other activation signals.
authors.affiliation: Section of Pathology, Institute of Immunological Science, Hokkaido University, Sapporo, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Kaneda
authors.forename: K
authors.initials: K
authors.lastname: Iwabuchi
authors.forename: K
authors.initials: K
authors.lastname: Onoé
mesh_terms: D000818:Animals; D017209:Apoptosis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002999:Clone Cells / Q000276:immunology; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006825:Hybridomas / Q000276:immunology*; D017136:Ion Transport / Q000187:drug effects; D007476:Ionophores / Q000494:pharmacology; D007739:L Cells / Q000276:immunology; D007940:Leukemia L5178 / Q000473:pathology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000502:physiology*
chemical_list: D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D000949:Histocompatibility Antigens Class II; D007476:Ionophores; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D019014:fas Receptor; D000001:Calcimycin; D002118:Calcium