The Expression Of CXCL11/I-TAC And Its Receptor CXCR3 In The Lesions Of Lichen Planus

IntroductionChemokine is a kind of inducible and secretary proinflammatary cytokines,with relative molecular weight of about 8～10 kDa.It was secreted by activated leukocytes,endothelioid cells,epithelioid cells and various malignant cells.Chemokine can be divided into 4 subgroups:C,CC,CXC and CX3C.They play their roles by chemokine receptors,which are on their target cells' membranes. Chemokines and their receptors play a major role in cell migration,wound healing,Th1/Th2 cell development,blood vessel formation,tumor growth and metastasis,infection,lymphoid organ development,dendritic cells maturity and so on.IFN-inducible T cellαchemoattractant(CXCL11/I-TAC),IFN-γ-inducible protein-10(CXCL10/IP10) and monokine induced by gamma-interferon(CXCL9/Mig) are type 1 chemokines which specifically chemoattracts CXCR3-expressing Th1/Tc1 cells.Thymus and activation-reguated(CCL17/TARC) and macrophage-derived chemokine(CCL22/MDC) are type 2 chemokines which specifically chemoattracts CCR4-expressing Th2/Tc2 cells.It was found recently that type 1 and type 2 chemokines were overexpressed in the epidermal keratinocytes of inflammatory dermatoses,such as psoriasis,lichen planus and atopic dermatitis.There have been increasing evidences that CXCL11/I-TAC and CXCL9/Mig are overexpressed in Th1-dominated skin disorders such as psoriasis,lichen planus,and that CCL22/MDC is highly expressed in a Th2-dominated skin disorder,atopic dermatitis.Th1 cytokine IFN-γand TNF-α.are overexpressed and play important roles in Th1-dominated skin diseases.In previous studies,the two cytokines have been shown to be strong inducers of CXCL11/I-TAC in keratinocytes.In our study,we investigate the expression and location of CXCL11/I-TAC and CXCR3 in lichen planus by immunohistochemistry.Materials and Methods We chose 44 cases of lichen planus that were diagnosed by clinical and pathological manifestations and 16 cases of normal skin samples from plastic surgery patients with no dermatological diseases as normal control.Immunohistochemistry was performed to detect the expression of CXCL11/I-TAC and CXCR3 in the lesions of lichen planus or normal skin.ResultsThe expressions of CXCL11/I-TAC and CXCR3 were significantly higher in the lesions of lichen planus than those in normal skin(both P＜0.0005).ConclusionThe upregulated expressions of CXCL11/I-TAC and CXCR3 in the lesions of lichen planus,a Th1-dominated inflammatory skin disease,indicate that they may play important roles in the pathogenesis of this type of inflammatory skin diseases including lichen planus.