Establishment Of A Mouse Model Of Chronic Eczema And Study Of The Efficacy Of Tacrolimus On It

BackgroundThe most of chronic eczema are associated with type IVallergy, which is cell immunity mediated by T cell.So far,there few reports of eczema modles,and mass of them are transgenic mouse.Tacrolimus is topical immunomodulators classified as calcineurin inhibitors.They belong to this group of substances with a high capacity to inhibit T lymphocyte activation. Although they also act on other cells playing a role in AD (mastocytes, Langerhans'cells, B lymphocytes),their action on restraining T lymphocytes seems to be the most important.The high efficacy and the low side-effect profile of tacrolimus treatment was the rationale for performing studies into the long-term management of AD. present, tacrolimus is usually used to treat AD, and seborrheic dermatitis, lichen planus, psoriasis, vitiligo, alopecia areata, etc.Compared to steroids, tacrolimus has more remarkable safty and comparable efficacy, therefore, it would be very promising in clinical applicationObjectiveTo establish the model of chronic eczema in mouse on its dorsum,and study the efficacy and mechanism of the tacrolimus ointment in the treatment of chronic eczema.Methods1.Establishment of model:dorsum of mice were repeatedly challenged with different concentration of 2,4-dinitro chlorobenzene(DNCB) respectively. Compare the difference of inflammation degree of lesion and quantity of inflammatory cell in histopathology.2. The 0.5%2,4-dinitro chlorobenzene (DNCB) was applied on the dorsum of mice to produce the chronic eczema models.3.compare the efficacy:with the tacrolimus ointment, halometasone cream and vaseline respectively. The distinctions of inflammation degree, quantity of inflammatory cell in histopathology,and levels of IL-2.IL-4.IL-5.IFN-γin lesion were detected.Results1. After treatment the mouse models established by 0.5%DNCB,the skin on dorsum present thickening, lichenification, and historical pathology result both meet with the representation of chronic eczema. The lesion of dorsum of mice modle distinction of inflammation degree of lesion and quantity of inflammatory cell in histopathology showed statistical significances (P<0.05) in different groups.2. The inflammation degree of lesion, quantity of inflammatory cell in histopathology, and levels of IL-4.IL-5 in lesion were all reduced by topical tacrolimus ointment, whereas levels of IL-2 and IFN-γwere increased.Conclusion1. Repeated challenge with 0.5% DNCB may induce chronic eczema in mice.2. Application of the tacrolimus ointment can effectively alleviate the inflammation degree of lesion on dorsum of mouse, reduce quantity of inflammatory cell in histopathology, and Adjust The level of cytokine (P<0.05). There is obviously treatment effect for chronic eczema, and compared to steroids, tacrolimus has more remarkable safty.