Molecular and biological characterization of human 4-1BB and its ligand.
4-1BB was originally described as a cDNA expressed by activated murine T cells and subsequently demonstrated to encode a member of the tumor necrosis factor receptor family of integral membrane proteins. Recently, we identified and cloned a murine ligand for 4-1BB (mu4-1BB-L) and demonstrated it to be a member of an emerging family of ligands with structural homology to tumor necrosis factor. To characterize further the role of 4-1BB in the immune response we undertook to clone the human homologue of 4-1BB-L. However, attempts to isolate a cDNA encoding the human 4-1BB-L by cross-hybridization with the murine cDNA were unsuccessful. Therefore we first utilized cross-species hybridization to isolate a cDNA encoding human 4-1BB (hu4-1BB). A fusion protein consisting of the extracellular portion of hu4-1BB coupled to the Fc region of human immunoglobulin G1 (hu4-1BB.Fc) was then used to identify and clone a gene for human 4-1BB-L from an activated CD4+ T cell clone using a direct expression cloning strategy. Human 4-1BB-L shows 36% amino acid identity with its murine counterpart and maps to chromosome 19p13.3. Scatchard analysis demonstrated high-affinity binding of hu4-1BB.Fc to either native or recombinant human 4-1BB-L. Both monoclonal antibody to hu4-1BB and cells transfected with hu4-1BB-L induced a strong proliferative response in mitogen co-stimulated primary T cells. In contrast, ligation of 4-1BB on T cell clones enhanced activation-induced cell death when triggered by engagement of the TCR/CD3 complex.
Alderson
M R
MR
Department of Cellular Immunology, Immunex Research and Development Corporation, Seattle, WA 98101.
Smith
C A
CA
Tough
T W
TW
Davis-Smith
T
T
Armitage
R J
RJ
Falk
B
B
Roux
E
E
Baker
E
E
Sutherland
G R
GR
Din
W S
WS
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D001483:Base Sequence; D001667:Binding, Competitive / Q000502:physiology; D016923:Cell Death / Q000276:immunology; D002478:Cells, Cultured; D002874:Chromosome Mapping; D018076:DNA, Complementary; D005434:Flow Cytometry; D015698:Genomic Library; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D012333:RNA, Messenger; D017475:Receptors, Nerve Growth Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C505714:TNFRSF9 protein, human; C505715:Tnfrsf9 protein, mouse; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9