title: Effects of non-MHC background genes on the induction of CD4+ T cells that prevent rejection of a highly immunogenic tumor, FBL-3.
abstract: This study showed that non-MHC genes common to (DBA/2 H-2d) and (DBA/1 H-2q) gave rise to suppressor T (Ts) cells in the hybrid F1 mice between C57BL/6 (B6) strain in the anti-FBL-3 tumor responses. FBL-3, a Friend virus-induced tumor cell line of B6 mouse origin, is highly immunogenic as shown by findings that syngeneic and hybrid F1 mice with several other inbred strains rejected up to 3 x 10(7) tumors cell inoculated s.c. and generated potent CTL responses after mixed lymphocyte tumor cell culture. In contrast to these mice, (B6 x DBA/2) and (B6 x DBA/1)F1 mice did not reject the tumor as the tumor doses increased. Progressive tumor growth in these F1 mice was blocked by an i.p. injection of cyclophosphamide (250 mg/kg) on day 10, but not on day 5, after tumor cell inoculation. Anti-CD4 (GK1.5) mAb exerted similar therapeutic effects against tumor when given twice, between day 0 and 10, whereas the additional injection of anti-CD8 mAb enhanced the tumor growth in mice that otherwise rejected the tumor. Thus, in the response of (B6 x DBA/2)F1 mice to FBL-3 tumor cells, CD4+ Ts seemed to down-regulate the immunologically mediated regression of the tumor produced by CD8+ CTL. This was evidenced by limiting dilution culture analyses, which showed that the frequency of an FBL-3-specific CTL precursor in the (B6 x DBA/2)F1 mice that rejected the tumor with anti-CD4 mAb was approximately 7- to 9-fold higher than that in mice in which the tumor regressed spontaneously.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Immunology and Cell Biology, Faculty of Medicine, Kyoto University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Morioka
authors.forename: M
authors.initials: M
authors.lastname: Iwashiro
authors.forename: Y
authors.initials: Y
authors.lastname: Matsubayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Teramura
authors.forename: K
authors.initials: K
authors.lastname: Kuribayashi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000235:genetics*; D005260:Female; D006824:Hybridization, Genetic / Q000235:genetics / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D016827:CD8 Antigens; D003520:Cyclophosphamide