Expression of indoleamine 2,3-dioxygenase in dermal fibroblasts functions as a local immunosuppressive factor.
As a possible way of making a non-rejectable skin substitute, here, we ask the question of whether the expression of indoleamine 2,3-dioxygenase (IDO) selectively suppresses immune, but skin, cell proliferation. To address this question, a series of experiments in which adenovirus (Ad-IDO) infected IDO expressing dermal fibroblasts were co-cultured with different types of immune cells were carried out. The immune cells were then harvested and evaluated for propidium iodide (PI) positive cells by FACS analysis. TUNEL assay was also carried out to determine the apoptotic status of these cells. The results showed that the expression of IDO in dermal fibroblasts significantly induces apoptotic death of PBMC, CD4(+)-, CD8(+)- and B cell-riched primary lymphocytes, Jurkat cells, and THP-1 cells. IDO-mediated damage of immune cells was restored by an addition of tryptophan and IDO inhibitor. Using the same approaches, we also demonstrated that skin cells and endothelial cells are remarkably resistant to tryptophan-deficient environment. Furthermore, no significant difference in cell proliferation between Ad-GFP (control)- and Ad-IDO-GFP-infected either keratinocytes or fibroblasts, was found. The results of this study, therefore, suggest that the expression of IDO by dermal fibroblasts mediates immune cell damage and this may shed a new light toward developing a non-rejectable skin substitute in the future.
Ghahary
Aziz
A
Department of Surgery, University of Alberta, Edmonton, Alberta, Canada. aghahary@ualberta.ca
Li
Yunyuan
Y
Tredget
Edward E
EE
Kilani
Ruhangiz T
RT
Iwashina
Takashi
T
Karami
Ali
A
Lin
Xiaoyue
X
D000256:Adenoviridae / Q000235:genetics; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006801:Humans; D007107:Immune System / Q000166:cytology / Q000502:physiology; D007166:Immunosuppressive Agents / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D007202:Indicators and Reagents; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D015603:Keratinocytes / Q000166:cytology; D008164:Luminescent Proteins / Q000235:genetics; D012867:Skin / Q000166:cytology / Q000378:metabolism*; D014162:Transfection; D014364:Tryptophan / Q000494:pharmacology; D014366:Tryptophan Oxygenase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
D007166:Immunosuppressive Agents; D007202:Indicators and Reagents; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D014364:Tryptophan; D014366:Tryptophan Oxygenase