CD5-mediated negative regulation of antigen receptor-induced growth signals in B-1 B cells.
A subset of B lymphocytes present primarily in the peritoneal and pleural cavities is defined by the expression of CD5 and is elevated in autoimmune diseases. Upon signaling through membrane immunoglobulin M (mIgM), splenic B lymphocytes (B-2) proliferate, whereas peritoneal B cells (B-1) undergo apoptosis. However, in CD5-deficient mice, B-1 cells responded to mIgM crosslinking by developing a resistance to apoptosis and entering the cell cycle. In wild-type B-1 cells, prevention of association between CD5 and mIgM rescued their growth response to mIgM crosslinking. Thus the B cell receptor-mediated signaling is negatively regulated by CD5 in normal B-1 cells.
Bikah
G
G
Department of Microbiology and Immunology and Center on Aging, University of Kentucky, Lexington, KY 40536, USA. sbonda@pop.uky.edu
Carey
J
J
Ciallella
J R
JR
Tarakhovsky
A
A
Bondada
S
S
D000818:Animals; D017209:Apoptosis; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D018956:CD5 Antigens / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D003432:Cross-Linking Reagents; D005260:Female; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism; D010529:Peritoneal Cavity / Q000166:cytology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction
D018956:CD5 Antigens; D003432:Cross-Linking Reagents; D007075:Immunoglobulin M; D016328:NF-kappa B; D011947:Receptors, Antigen, B-Cell; D002118:Calcium