Structure, expression, and T cell costimulatory activity of the murine homologue of the human B lymphocyte activation antigen B7.
Following occupancy of the T cell receptor by antigen, T cell proliferation and lymphokine production are determined by a second costimulatory signal delivered by a ligand expressed on antigen presenting cells. The human B cell activation antigen B7, which is expressed on antigen presenting cells including activated B cells and gamma interferon treated monocytes, has been shown to deliver such a costimulatory signal upon attachment to its ligand on T cells, CD28. We have cloned and sequenced the murine homologue of the human B7 gene. The predicted murine protein has 44% amino acid identity with human B7. The greatest similarity is in the Ig-V and Ig-C like domains. Murine B7 mRNA was detected in murine hematopoietic cells of B cell but not T cell origin. Cells transfected with murine B7 provided a costimulatory signal to human CD28+ T lymphocytes. These results demonstrate the costimulatory activity of murine B7 and provide evidence that the ligand attachment site is conserved between the two species.
Freeman
G J
GJ
Division of Tumor Immunology, Dana Farber Cancer Institute, Boston, Massachusetts.
Gray
G S
GS
Gimmi
C D
CD
Lombard
D B
DB
Zhou
L J
LJ
White
M
M
Fingeroth
J D
JD
Gribben
J G
JG
Nadler
L M
LM
D000595:Amino Acid Sequence; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D000954:Antigens, Surface / Q000235:genetics* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000502:physiology; D018122:B7-1 Antigen; D015152:Blotting, Northern; D015139:Blotting, Southern; D018106:CD28 Antigens; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D006801:Humans; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D011971:Receptors, Immunologic / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D018122:B7-1 Antigen; D018106:CD28 Antigens; D009841:Oligonucleotides; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D004247:DNA