Quantification of Bax/Bcl-2 ratios in peripheral blood lymphocytes, monocytes and granulocytes and their relation to susceptibility to anti-Fas (anti-CD95)-induced apoptosis.
Neutrophils have the shortest half-life among circulating leucocytes and rapidly undergo apoptosis in vitro. The homologous Bcl-2 and Bax proteins have opposing effects, with Bcl-2 extending cellular survival and Bax promoting cell death following an apoptotic stimulus. We determined Bcl-2 to Bax expression ratios in peripheral blood lymphocytes, monocytes and granulocytes and related them to the susceptibility of these cells to anti-Fas (anti-CD95)-induced apoptosis. Here, we show that Bax/Bcl-2 ratios are high in granulocytes and relatively low in monocytes and lymphocytes. Furthermore, we show a relation between this ratio in the different leucocyte subsets and their susceptibility to anti-Fas-induced apoptosis, with granulocytes showing the highest susceptibility, followed by monocytes and lymphocytes. It is concluded that the balance between Bcl-2 and Bax forms an apoptotic rheostat, which seems to determine sensitivity to apoptosis.
Van Der Vliet
H J
HJ
Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, The Netherlands.
Wever
P C
PC
Van Diepen
F N
FN
Yong
S L
SL
Ten Berge
I J
IJ
D000328:Adult; D017209:Apoptosis / Q000276:immunology*; D002478:Cells, Cultured; D005434:Flow Cytometry; D006098:Granulocytes / Q000276:immunology* / Q000473:pathology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology* / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000276:immunology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis* / Q000276:immunology; D051028:bcl-2-Associated X Protein; D019014:fas Receptor / Q000276:immunology*
C494826:BAX protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D019014:fas Receptor