Antigen receptor function in chronic lymphocytic leukemia B cells.
Functional studies revealed that two groups of B chronic lymphocytic leukemia (B-CLL) can be distinguished based on their capacity to mount a proliferative response following B-cell antigen receptor (BCR) cross-linking. The molecular basis for the functional distinction between these B-CLL groups most probably resides within or proximal to the BCR since non-responsive B-CLL, in marked contrast to responsive B-CLL, do not respond to BCR ligation with tyrosine phosphorylation of cellular substrates and increases in the free intracellular [Ca++]. Detailed biochemical analysis showed overall structural identity between responsive and non-responsive B-CLL with respect to both transmembrane and intracellular associates of the BCR complex. However expression levels of the protein tyrosine kinase syk, which is a key enzyme for the early signalling through the BCR, were found to be markedly lower in non-proliferating B-CLL. Here we will review current functional and biochemical data on responding and non-responding B-CLL and discuss the relevance of these findings for disease progression and our insight into the immunobiology of B-CLL.
Lankester
A C
AC
Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, University of Amsterdam, The Netherlands.
Schijndel
G M
GM
Pakker
N G
NG
Van Oers
R H
RH
van Lier
R A
RA
D002455:Cell Division / Q000276:immunology; D003937:Diagnosis, Differential; D018450:Disease Progression; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis / Q000276:immunology*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000097:blood*
D011947:Receptors, Antigen, B-Cell; D011505:Protein-Tyrosine Kinases