Human fetal retinal pigment epithelium induces apoptosis in human T-cell line Jurkat which is independent from its expression of TRAIL.
OBJECTIVE
To evaluate whether human fetal retinal pigment epithelial (HFRPE) cells express TRAIL (tumor necrosis factor related apoptosis inducing ligand). The role of TRAIL in HFRPE induced apoptosis was evaluated.


METHODS
Pure cultures of HFRPE cells were isolated. The expression of TRAIL protein and mRNA in non-activated and IFN-gamma activated HFRPE cells was evaluated with RT-PCR. The role of TRAIL in HFRPE induced apoptosis was assessed by incubating HFRPE cells with human T-cell leukemia line Jurkat (Jkt) in the presence or absence of neutralizing TRAIL antibodies. Cultures were pulsed with [(3)H]-thymidine to measure Jkt cell proliferation. The role of TRAIL was further examined by western blott evaluating the cleavage of caspases 8 and 10 in Jkt cells after their incubation with HFRPE cells.


RESULTS
HFRPE cells expressed TRAIL mRNA. The expression of TRAIL mRNA and protein was up-regulated by IFN-gamma activation. However, anti-TRAIL antibodies were not able to prevent the HFRPE induced suppression of Jkt cell proliferation. The caspases 8 and 10 were also not cleaved in Jkt cells after their incubation with IFN-gamma activated HFRPE cells.


CONCLUSIONS
Although HFRPE cells express TRAIL and its expression is upregulated by IFN-gamma activation, TRAIL is not involved in HFRPE induced apoptosis in Jkt cells. Currently the role of TRAIL in HFRPE cells is under investigation.
Farrokh-Siar
Lili
L
Department of Ophthalmology, University of Chicago, IL 60637, USA. Ifarrokh@midway.uchicago.edu
Rezai
Kourous A
KA
Palmer
Ellen M
EM
van Seventer
Jean
J
Hamann
Kimm J
KJ
Rajadurai
Henrietta
H
Patel
Samir C
SC
Ernest
J Terry
JT
van Seventer
Gijs A
GA
D000906:Antibodies / Q000276:immunology; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D053455:Caspase 10; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004792:Enzyme Precursors / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D019169:Jurkat Cells / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000196:embryology*; D012333:RNA, Messenger / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D000906:Antibodies; D051017:Apoptosis Regulatory Proteins; D004792:Enzyme Precursors; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053455:Caspase 10; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; C506438:CASP10 protein, human