Identification and characterization of rat AILIM/ICOS, a novel T-cell costimulatory molecule, related to the CD28/CTLA4 family.
Activation-inducible lymphocyte immuno-mediatory molecule (AILIM) is an inducible cell surface glycoprotein expressed on thymocytes and activated lymphocytes. Specific monoclonal antibody to rat AILIM induced the cell aggregation of a rat thymoma cell line and ConA-activated splenocytes. In the present study, we identified the primary structure of two species of rat AILIM by expression cloning. We also cloned mouse and human AILIM homologues and the predicted amino acid sequences were identical to those of the inducible costimulator ICOS/CRP-1, which belongs to the CD28/CTLA4 family. Although the human and mouse AILIM/ICOS molecule is localized on T-cells, the major population of AILIM/ICOS-positive cells in rat splenocyte was CD45RA-positive B-cells. The expression level of AILIM/ICOS on T-cells was relatively low; however, its expression was drastically induced by the treatment with PMA plus Ca-ionophore or the engagement of CD3 and these costimulatory molecules. Almost all T-cells exhibited potency as to its expression. Functional analysis of AILIM/ICOS demonstrated that AILIM-mediated costimulation was relatively weak compared to that of human.
Tezuka
K
K
Pharmaceutical Frontier Research Laboratories, JT Inc., Fukuura 1-13-2, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan.
Tsuji
T
T
Hirano
D
D
Tamatani
T
T
Sakamaki
K
K
Kobayashi
Y
Y
Kamada
M
M
D000069594:Abatacept; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D018106:CD28 Antigens / Q000235:genetics / Q000276:immunology; D060908:CTLA-4 Antigen; D003001:Cloning, Molecular; D006801:Humans; D018796:Immunoconjugates; D060889:Inducible T-Cell Co-Stimulator Protein; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D016415:Sequence Alignment; D013601:T-Lymphocytes
D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556707:Ctla4 protein, mouse; C556708:Ctla4 protein, rat; C556692:ICOS protein, human; C556694:Icos protein, mouse; C556695:Icos protein, rat; D018796:Immunoconjugates; D060889:Inducible T-Cell Co-Stimulator Protein; D000069594:Abatacept