Quantitative characterization and potential function of membrane Fas/APO-1 (CD95) receptors on leukaemic cells from chronic B and T lymphoid leukaemias.
The expression and function of the Fas-receptor (Fas-R) were examined in chronic lymphocytic leukaemia (CLL), hairy cell leukaemia-variant (HCL-v) and adult T-cell leukaemia (ATL). The expression of Fas-R in freshly isolated leukaemic cells was qualitatively and quantitatively different between each disease; faint in B-CLL, moderate in HCL-v and strong in ATL. Both full-length and alternatively spliced truncated forms of Fas mRNA were detected even in CLL B cells with faint to negative Fas-R, and Fas mRNA was also shown to be capable of increasing in vitro expression, i.e. the message was functional. In contrast, Fas-R expression on ATL cells was heterogenous and usually intense with a mean density approximately 3-fold higher than that of normal T cells. Fas-R was confirmed to have the potential function for anti-Fas monoclonal antibody-mediated cell death in vitro in Fas-R+ ATL cells. The expression level of Fas-R on the cells was higher in chronic than acute ATL (10,360 v 6260 antibody-binding capacity per cell, mFasABC; P<0.05) and was inversely correlated with serum LDH activity, suggesting that the strong Fas-R accounts for the slow progression of chronic ATL and the negative Fas-R protects from Fas-mediated cell death. These results show that Fas-R expression on leukaemic cells is valuable in their characterization and perhaps their function, and may contribute to the progression and immune evasion of malignant clones.
Kamihira
S
S
Department of Laboratory Medicine, Nagasaki University School of Medicine, Japan.
Yamada
Y
Y
Hirakata
Y
Y
Tsuruda
K
K
Sugahara
K
K
Tomonaga
M
M
Maeda
T
T
Tsukasaki
K
K
Atogami
S
S
Kobayashi
N
N
D017209:Apoptosis; D005434:Flow Cytometry; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007943:Leukemia, Hairy Cell / Q000378:metabolism* / Q000473:pathology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism* / Q000473:pathology; D015458:Leukemia, T-Cell / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000378:metabolism*
D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D019014:fas Receptor