Characterization of endogenous Chinese hamster ovary cell surface molecules that mediate T cell costimulation.
Chinese hamster ovary (CHO) cells are commonly used in the generation of transfectants for use in in vitro costimulation assays. However, we have noted that nontransfected CHO cells can themselves provide a low-level B7/CD28 independent costimulatory signal for CD3-mediated murine T cell activation and IL-2 production. This study set out to identify those molecules that contribute to this CHO-dependent costimulatory activity. We describe a CHO subline capable of delivering potent CD28-independent costimulation to murine T cells and the generation of monoclonal antibodies against these CHO cells that inhibited this costimulatory activity. These blocking antibodies do not affect CHO cell-independent costimulation or bind mouse cells, suggesting an effect mediated by their target molecules on the costimulatory competent CHO cells. Immunoprecipitation and expression cloning revealed that these antibodies bound the hamster homologues of Crry (CD21/35), CD44, CD54 (ICAM-1), CD63, CD87, CD147, and an 80- to 90-kDa protein which could not be cloned. Expression of these hamster genes on COS cells demonstrated that hamster CD54 was able to costimulate both CD3-mediated IL-2 secretion and T cell proliferation by naive murine T cells independent of the other molecules identified.
Gaglia
J L
JL
Center For Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Mattoo
A
A
Greenfield
E A
EA
Freeman
G J
GJ
Kuchroo
V K
VK
D000818:Animals; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology; D016466:CHO Cells; D019556:COS Cells; D002522:Chlorocebus aethiops; D006224:Cricetinae; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D008565:Membrane Proteins / Q000032:analysis* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010980:Platelet Membrane Glycoproteins / Q000032:analysis / Q000276:immunology; D011956:Receptors, Cell Surface / Q000032:analysis / Q000276:immunology; D011951:Receptors, Complement / Q000032:analysis / Q000276:immunology; D017463:Receptors, Complement 3b; D055293:Receptors, Urokinase Plasminogen Activator; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D060149:Tetraspanin 30
D015703:Antigens, CD; C554586:CD63 protein, human; C554587:Cd63 protein, mouse; C081470:Cr1l protein, mouse; D018960:Hyaluronan Receptors; D008565:Membrane Proteins; C524898:PLAUR protein, human; D010980:Platelet Membrane Glycoproteins; C524899:Plaur protein, mouse; D011956:Receptors, Cell Surface; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D055293:Receptors, Urokinase Plasminogen Activator; D060149:Tetraspanin 30; D018799:Intercellular Adhesion Molecule-1