Characterization of a mutant T-cell hybridoma line with defects in the TCR-mediated apoptotic pathway.
A mutant T-cell hybridoma line named mutant 51 was developed that, unlike the parental line, did not die after T-cell receptor (TCR) engagement and demonstrated reduced death in response to dexamethasone. Intracellular calcium measurements showed that available calcium stores were markedly reduced in the mutant cell line. Unlike control cells, secretion of IL-2 from mutant cells was also greatly reduced, although addition of exogenous IL-2 did not facilitate increased apoptosis. Although levels of the cell death gene product Nur77 were equivalent, additional studies showed that mutant cells expressed Nur77 predominantly in the cytoplasm following TCR engagement, while parental cells displayed a nuclear translocalization of Nur77. In addition, Fas levels and Fas ligand dependant killing were both markedly reduced in the mutant clone. From these data we hypothesize a role for available calcium stores and Nur77 nuclear localization in TCR-mediated apoptosis in T-cell hybridomas.
Morgan
G
G
Department of Veterinary and Animal Sciences, Paige Labs, University of Massachusetts, Amherst, 01003, USA.
Smith
S
S
Pak
J
J
Marshak-Rothstein
A
A
Fissore
R
R
Osborne
B
B
D017209:Apoptosis / Q000235:genetics*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D006825:Hybridomas / Q000502:physiology*; D007150:Immunohistochemistry; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000378:metabolism; D009154:Mutation; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D011987:Receptors, Steroid; D015398:Signal Transduction / Q000235:genetics*; D013601:T-Lymphocytes / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism
D015220:Calcium Channels; D004268:DNA-Binding Proteins; D053222:Fas Ligand Protein; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011948:Receptors, Antigen, T-Cell; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors; D000001:Calcimycin; D003907:Dexamethasone; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium