Human tenon's fibroblast-produced ifnbeta and the prevention of t-cell apoptosis.
OBJECTIVE
Fibroblast-T-cell interactions may contribute to the development of chronic inflammation, a risk factor for trabeculectomy failure. This study was undertaken to determine whether normal and growth-arrested human Tenon's fibroblasts (HTF) can prevent cytokine deprivation-mediated T-cell apoptosis through the secretion of interferon (IFN)beta.


METHODS
HTF were used either untreated or pretreated with mitomycin-C (MMC; 0.1 or 0.4 mg/ml) or 5-fluorouracil (5FU; 25 or 50 mg/ml). IL2-deprived T cells were cocultured with HTF. T-cell viability was measured at specific time points. Human Tenon's fibroblast-conditioned medium was used either untreated or treated with a neutralizing antibody against IFNbeta to block its action, after which IL2-deprived T cells were added and T-cell viability was measured. An image analysis system was used to determine the production of IFNbeta by either untreated or MMC-treated HTF.


RESULTS
T-cell viability was significantly greater when T cells were cocultured with both untreated and growth-arrested HTF than when T cells were cultured alone (day 7, P = 0.0001). Neutralizing the action of IFNbeta blocked HTF-mediated T-cell rescue from apoptosis. Both untreated and growth-arrested HTF secrete IFNbeta, and MMC at 0.4 mg/ml appeared to increase IFNbeta production.


CONCLUSIONS
Cytokine deprivation-mediated T-cell apoptosis can be prevented by the action of IFNbeta secreted by both normal and growth-arrested HTF, which suggests that growth-arrested HTF can still participate in an aggressive wound-healing reaction by mediating a persistent inflammatory phase. This may partly explain why some trabeculectomies fail in high-risk patients, despite the use of antimetabolites.
Chang
L
L
Wound Healing Research and Glaucoma Units, Institute of Ophthalmology, University College, London, UK. changevans@aol.com
Crowston
J G
JG
Sabin
C A
CA
Khaw
P T
PT
Akbar
A N
AN
D017209:Apoptosis; D002470:Cell Survival; D002478:Cells, Cultured; D018920:Coculture Techniques; D003239:Connective Tissue Cells / Q000378:metabolism; D019610:Cytoprotection / Q000502:physiology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D016899:Interferon-beta / Q000096:biosynthesis*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D016685:Mitomycin / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology*
D016685:Mitomycin; D016899:Interferon-beta; D007770:L-Lactate Dehydrogenase; D005472:Fluorouracil