Expression of the B8.7 antigen on hairy cells and relation with the LMW-BCGF response.
Hairy cells are classified as B cell tumors at a preplasma cell stage of differentiation and are believed to represent cells undergoing a switch process. These cells are stimulated in vitro to DNA synthesis and multiplication in the presence of the lymphokine LMW-BCGF. We have tested the level of expression on these cells of the newly described B8.7 activation marker which has been reported to be associated with the capacity of various B cells to respond to LMW-BCGF. The presence of this marker has been readily detected on the hairy cells of 10 of the 12 patients tested in this study; interestingly, for one of the negative cases, the tumor cells were unable to proliferate in response to LMW-BCGF. As on normal B cells, a marked inhibition of the LMW-BCGF dependent response could be achieved in the presence of a monoclonal anti-B8.7 antibody, sustaining the proposal that the B8.7 molecule is involved in the signaling pathway of this growth factor. IFN-alpha is highly efficient in the therapy of hairy cell leukemia (HCL), and we confirm in the present study that IFN-alpha also inhibits the LMW-BCGF dependent proliferation of hairy cells in vitro. In addition, we show that this inhibition is independent of a significant modulation of the B8.7 antigen, a molecule putatively associated with the LMW-BCGF receptor.
Génot
E
E
Unité INSERM U 196, Institut Curie, Paris, France.
Leprince
C
C
Richard
Y
Y
Petit-Koskas
E
E
Falcoff
E
E
Galanaud
P
P
Sigaux
F
F
Kolb
J P
JP
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology*; D002455:Cell Division / Q000187:drug effects; D005260:Female; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D015847:Interleukin-4; D007378:Interleukins / Q000032:analysis* / Q000494:pharmacology; D007943:Leukemia, Hairy Cell / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000032:analysis
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; C059492:B8.7 antigen, human; D007370:Interferon Type I; D007378:Interleukins; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D015847:Interleukin-4