Murine B-cell activation via CD38 and protein tyrosine phosphorylation.
CD38 has been implicated in the regulation of both proliferation and rescue from apoptosis of B cells. The signalling events associated with CD38-mediated activation of murine B cells are, as yet, not well defined but it is clear that ligation of CD38 by a mitogenic antibody, NIMR-5, induces a calcium influx in resting B cells. Interestingly, however, cross-linking of CD38 does not mobilize intracellular stores of calcium. We now provide a rationale for these findings by demonstrating that CD38 is not coupled to the generation of inositol phosphates in resting B cells. We do, however, show that CD38 ligation stimulates one, or more, protein tyrosine kinase activities which may play a central role in the transduction of CD38-mediated signals leading to B-cell activation.
Kirkham
P A
PA
Department of Immunology, Institute for Animal Health, Pirbright Laboratory, Surrey, UK.
Santos-Argumedo
L
L
Harnett
M M
MM
Parkhouse
R M
RM
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D007295:Inositol Phosphates / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D008562:Membrane Glycoproteins; D051379:Mice; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*
D015703:Antigens, CD; D000943:Antigens, Differentiation; D007295:Inositol Phosphates; D008562:Membrane Glycoproteins; D011505:Protein-Tyrosine Kinases; D036541:ADP-ribosyl Cyclase; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1