Desiccating stress promotion of Th17 differentiation by ocular surface tissues through a dendritic cell-mediated pathway.
OBJECTIVE
To explore the phenomenon that corneal and conjunctival tissues subjected to desiccating stress (DS) promote Th17 differentiation by stimulating the production of Th17-inducing cytokines through a dendritic cell (DC)-mediated pathway.


METHODS
Experimental dry eye was created by subjecting C57BL/6 mice to desiccating environmental stress. Corneal and conjunctival explants from dry eye or control mice were cocultured with DCs for 24 hours before CD4(+) T cells were added for an additional 4 to 7 days. Expression of Th17-associated genes in the cornea, conjunctiva, DCs, and CD4(+) T cells was evaluated by real-time PCR. Cytokine concentrations in coculture supernatants were measured by immunobead assay. IL-17-producing T cells were identified by ELISPOT bioassay.


RESULTS
Higher levels of IL-17A, TGF-beta1, TGF-beta2, IL-6, IL-23, and IL-1beta mRNA transcripts and TGF-beta1, IL-6, and IL-1beta protein were observed in corneal epithelium and conjunctiva from dry eye mice. DCs cocultured with epithelial explants from dry eye mice for 2 days produced higher levels of TGF-beta1, IL-6, IL-23, and IL-1beta mRNA transcripts and of TGF-beta1, IL-6, and IL-1beta protein. CD4(+) T cells cocultured with DCs and epithelial explants from dry eye mice expressed increased levels of IL-17A, IL-17F, IL-22, CCL-20, and retinoic acid receptor-related orphan receptor-gammat mRNA transcripts and increased IL-17A protein and number of IL-17-producing T cells (Th17 cells).


CONCLUSIONS
These findings demonstrate that DS creates an environment on the ocular surface that stimulates the production of Th17-inducing cytokines by corneal and conjunctival epithelia that promote Th17 differentiation through a dendritic cell-mediated pathway.
Zheng
Xiaofen
X
Department of Ophthalmology, Baylor College of Medicine, Ocular Surface Center, Cullen Eye Institute, Houston, Texas 77030, USA.
de Paiva
Cintia S
CS
Li
De-Quan
DQ
Farley
William J
WJ
Pflugfelder
Stephen C
SC
D000818:Animals; D001854:Bone Marrow Cells; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D018920:Coculture Techniques; D003228:Conjunctiva / Q000378:metabolism*; D003315:Cornea / Q000378:metabolism*; D003713:Dendritic Cells / Q000502:physiology*; D003890:Desiccation; D004195:Disease Models, Animal; D015352:Dry Eye Syndromes / Q000139:chemically induced / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression / Q000502:physiology; D007124:Immunoenzyme Techniques; D020381:Interleukin-17 / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012601:Scopolamine / Q000633:toxicity; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D020381:Interleukin-17; D012601:Scopolamine