Establishment and characterization of a Fas-resistant T cell line.
Fas is a cell surface receptor that controls a signal transduction pathway leading to apoptosis. We established an antihuman Fas monoclonal antibody (mAb)-resistant variant, kit-225-FR, from the human T cell line, kit-225. Flow cytometric analysis revealed that the expression of Fas molecules on kit-225-FR was preserved. The defect in Fas molecule was not detected either by reverse transcription polymerase chain reaction (PCR) analysis of the Fas transcript or by PCR-single strand conformation polymorphism analysis of the Fas gene in kit-225-FR. Although kit-225-FR was resistant to a high concentration of anti-Fas mAb, apoptosis could be induced, as with the wild type, by exogenous C2-ceramide exposure. MORT1/FADD was expressed at wild-type level in kit-225-FR, as determined by Western blot analysis. It therefore appears that the apoptotic signal transduction in kit-225-FR is defective between FADD and the sphingomyelin-ceramide pathway. By comparing the differences from the wild-type kit-225, kit-225-FR would serve as a useful cell line for analyzing Fas-specific signal transduction pathways in detail.
Higuchi
M
M
First Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Horiuchi
T
T
Sawabe
T
T
Yoshizawa
S
S
Nagasawa
K
K
Niho
Y
Y
D017209:Apoptosis / Q000276:immunology*; D002518:Ceramides / Q000627:therapeutic use; D006801:Humans; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000097:blood* / Q000235:genetics
D002518:Ceramides; D019014:fas Receptor; D011505:Protein-Tyrosine Kinases