title: T cell proliferation-augmenting activities of the gene 3 protein derived from a phage library clone with CD80-binding activity.
abstract: We have isolated a phage clone, F2, by panning a phage library with a CTLA4-conformation recognizing mAb (anti-CTLA4 mAb). The unique sequence of 15 amino acids with an internal disulfide bond was inserted in the gene 3 proteins of F2 phage clone (F2-g3p). We show here that 1) F2-g3p was recognized with anti-CTLA4 mAb but not with anti-CD28 mAb, and 2) F2-g3p bound to CD80 but not to CD86. The surface plasmon resonance analysis showed that F2-g3p strongly bound CD80. F2-g3p inhibited the binding of CTLA4 to CD80 but not to CD86. In contrast, F2-g3p weakly inhibited the binding of CD28 with CD80. When hen egg lysozyme (HEL)-primed lymph node cells were stimulated with HEL in the presence of F2-g3p in vitro, cell proliferation was highly potentiated. In the absence of antigenic stimulation, F2-g3p induced no T cell proliferation, indicating the costimulatory nature of F2-g3p. The T cell-augmenting activity of the F2 clone was eliminated when the F2 clone was preincubated with CD80-Ig before the addition to the cultures, indicating the involvement of CD80-binding in the F2-g3p-mediated immunopotentiation. Thus, the F2 motif conferred CD80-binding activity and an immunoregulatory function to the g3p.
authors.affiliation: Department of Bioengineering, Faculty of Engineering, Kagoshima University, Korimoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fukumoto
authors.forename: N
authors.initials: N
authors.lastname: Torigoe
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Kajiwara
authors.forename: K
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism; D018122:B7-1 Antigen / Q000378:metabolism*; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000276:immunology / Q000378:metabolism*; D060908:CTLA-4 Antigen; D036022:Capsid Proteins; D003001:Cloning, Molecular; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015723:Gene Library; D006801:Humans; D018796:Immunoconjugates; D017912:Inovirus / Q000235:genetics*; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014760:Viral Fusion Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497964:CD86 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D036022:Capsid Proteins; C497965:Cd86 protein, mouse; C556707:Ctla4 protein, mouse; D004268:DNA-Binding Proteins; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D014760:Viral Fusion Proteins; D000069594:Abatacept