CD40-ligation-mediated protection from apoptosis of a Fas-sensitive Hodgkin's-disease-derived cell line.
Modulation of Fas expression and function by CD40 ligation was investigated in the Fas-sensitive human Hodgkin's disease cell line HDLM2. The recombinant human trimeric soluble CD40L (sCD40L) protected this cell line from apoptosis induced by an agonistic Fas antibody at all concentrations tested. sCD40L also protected HDLM2 when added up to 2 h after Fas ligation. Apoptosis induced by a cell-permeable synthetic ceramide could not be prevented by sCD40L. Thus, CD40 ligation is likely to intervene in the early phases of the Fas signal transduction pathway. When CD40 ligation preceded Fas ligation, it rendered the cells refractory to Fas-induced apoptosis. sCD40L-mediated protection could not be attributed to reduction in surface Fas expression, increase in Bcl-2 levels or to increase in the levels of soluble Fas isoforms.
Metkar
S S
SS
Immunology Division, Cancer Research Institute, Tata Memorial Centre, Parel, Mumbai, India. cri3@soochak.ncst.ernet.in
Naresh
K N
KN
Redkar
A A
AA
Nadkarni
J J
JJ
D017209:Apoptosis / Q000502:physiology*; D019013:CD40 Antigens / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D023201:CD40 Ligand; D053222:Fas Ligand Protein; D006689:Hodgkin Disease / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007536:Isomerism; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000096:biosynthesis / Q000378:metabolism
D019013:CD40 Antigens; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D018124:Receptors, Tumor Necrosis Factor; D019014:fas Receptor; D023201:CD40 Ligand