Expression Of Th17Type Cytokine In Experimental Keratomycosis

Objective To detect the expression of Th17type cotokine in a mouse model ofFusarium solani keratitis, and initially investigate the role of Th17cellor IL-17in keratomycosis.Methods A Balb/c mouse model of Fusarium solani keratitis was established by“epikeratophakia with the aid of corneal epithelium erasion” on the righteye.the fungal concentration was106colony-forming units(CFU) perml.Controls received phosphate-buffered saline (PBS) instead. At1,3,5,7,12d after inoculation, the appearance of corneal ulcer wasobserved by slitlamp and were given semiquantitative clinical scoring. At1,3,5,7d infected corneas were subjected to hematoxylin-eosin(HE)staining. The cytokine production of Th17cells,(interleukin)IL-17, weredetected respectively expression of mRNA and protein levels using realtime PCR and ELISA．The transcription factor RORγt mRNA levels werealso detected by real time PCR.Results1.Features of FKAll mice model was established successfully.At early time inflammatoryreaction was progressively increased,3d after infection the corneas weregray haze lesions,it was most severe and typical at5d but relievedgradually after7d. infection，the difference of clinical scorings wasstatistical significance among each other(P＜0.01) except3d vs7d.2.HE stainingAt the beginning of infection the corneal stromal were edematus,polymorphonuclear granulocyte infiltration increased significantly.At5dcorneal stromal disordered,then inflammatory cells diminished obviouslyand ulcer has been replaced by scar tissue after7d.3. Expression of inflammatory cytokines and transcription factorThe expression of Th17type cytokine (IL-17) and Th17cells’specific transcription factor (ROR γt) mRNA in the infectious cornea wassignificantly higher than the injury control group (P <0.01) at3,5and7d,in the FK group the highest expression level was detected at day5(P<0.01); at different time points after infection the IL-17proteinexpression was significantly higher than the injury control group (P<0.01).Conclusions The new CD4+cell subsets, Th17cell, was differentiated in the fungalkeratitis, and participated in the immune responses of this disease.Th17cytokine (IL-17) played an important role in fungal keratitis.