Regulation of platelet-activating factor receptor expression in human B cells and B cell lines.
We extended our previous data regarding the modulation of human platelet-activating factor receptor (hPAF-R) expression on human B cell lines as well as normal B cells. First, we showed that hPAF-R mRNA was present in B cell lines expressing membrane hPAF-R, but was absent from cell lines devoid of hPAF-R. Second, enhanced hPAF-R membrane expression induced in IM9 line by IL4 was preceeded by hPAF-R mRNA accumulation that was detectable by 8 h and which peaked at 24 h. Similar results were observed for 10 nM platelet-activating factor treatment, which increased hPAF-R mRNA content up to 120% at 48 h, whereas hPAF-R membrane expression was up-regulated by 130%. Third, our data indicate that functional hPAF-R are expressed on resting, as well as on activated, B cells and that B cell activation is required for maintaining hPAF-R membrane and mRNA expression. Thus, in normal B cells, as well as in B cell lines, transcriptional regulation and/or messenger stability control hPAF-R expression.
INSERM U 131, Institut Paris-Sud sur les Cytokines, Clamart, France.
C M
CM
Nguer
D
D
Treton
M
M
Rola-Pleszczynski
Z
Z
Mishal
Y
Y
Thomas
P
P
Galanaud
Y
Y
Richard
D001402:B-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D015854:Up-Regulation
D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D015847:Interleukin-4