Identification, by protein sequencing and gene transfection, of sgp-60 as the murine homologue of CD48.
We have recently described a murine lymphocyte protein, provisionally termed sgp-60, which is expressed on virtually all lymphocytes of both T- and B-cell origin. A hamster monoclonal antibody to sgp-60 can inhibit interleukin-2 (IL-2) production, IL-2-receptor expression, and T-cell proliferation, events normally observed after stimulation of T cells with an antibody to the T-cell receptor/CD3 complex or with the lectin concanavalin A. Our previous studies did not reveal the molecular nature of the sgp-60 antigen. Purification of sgp-60 and protein sequencing demonstrate that sgp-60 is identical to the CD48 antigen, a ligand for the CD2 antigen, which is also called Blast-1 in humans, BCM1 in mice, and OX-45 in rats. The identity of sgp-60 and CD48 was independently confirmed in gene transfection experiments. The anti-sgp-60 monoclonal antibody was selectively reactive with COS-7 cells transfected with a BCM1 cDNA clone but not with Kb-transfected controls. The results of the present report, together with our previous functional studies, may have implications for the role of CD2 and CD48 in murine T-cell activation.
Cabrero
J G
JG
Department of Pathology, Harvard Medical School, Boston, MA 02115.
Freeman
G J
GJ
Lane
W S
WS
Reiser
H
H
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000235:genetics*; D001483:Base Sequence; D000071178:CD48 Antigen; D002460:Cell Line; D004247:DNA / Q000235:genetics; D015723:Gene Library; D006801:Humans; D008223:Lymphoma; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000071178:CD48 Antigen; C000604065:CD48 protein, human; C000604066:Cd48 protein, mouse; C000604067:Cd48 protein, rat; D009838:Oligodeoxyribonucleotides; D004247:DNA