The Expression of Plasmacytoid Dendritic Cells and TLR7/9-MyD88-IRAKs Pathway in Chronic Eczema Lesions

Jiamin Wen,1 Jitian Weng,2 Wei Lu,3 Xiaohua Tao,3 Hao Cheng,4,&ast; Yi Tang3,&ast; 1Department of Dermatology, People’s Hospital of Tiantai County, Zhejiang University, Taizhou, People’s Republic of China; 2School of Public Health, Hangzhou Normal University, Zhejiang University, Hangzhou, People’s Republic of China; 3Center for Plastic & Reconstructive Surgery, Department of Dermatology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Zhejiang University Hangzhou 310014 People’s Republic of China; 4Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yi Tang, Center for Plastic & Reconstructive Surgery, Department of Dermatology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Zhejiang University, 158 Shangtang Road, Xiacheng District, Hangzhou, 310014, People’s Republic of China, Tel +86-13968076453, Fax +86-0571-85335800, Email tangyi@hmc.edu.cn Hao Cheng, Zhejiang University School of Medicine Sir Run Run Shaw Hospital, Hangzhou, Zhejiang, 310016, People’s Republic of China, Tel +86-13588706943, Fax +86-571-86006975, Email chenghao1@zju.edu.cnPurpose: To investigate the expression of Plasmacytoid Dendritic Cells (pDCs) and TLR7/9-MyD88-IRAKs pathway in chronic eczema lesions.Patients and Methods: Lesional tissues and the surrounding healthy tissues were collected from 25 individuals with chronic eczema, and immunohistochemistry was used to detect and comparatively analyze the expression profile of CD123, CD2AP, toll-like receptor 7 (TLR7), toll-like receptor 9 (TLR9) along with interleukin-1 receptor-associated kinase 1 (IRAK1) and interferon regulatory factor 7 (IRF7) in signaling pathways.Results: The positive rates of CD2AP + pDC and CD123 + pDC in lesional tissues were significantly elevated compared to the surrounding healthy tissues (P < 0.05). They were distributed in both the epidermal and dermal layers of the lesional tissue, but the majority were in the dermal layer. The TLR7, TLR9, IRAK1 and IRF7 were more expressed in dermal layers of the lesional tissue with higher positive rates of expression compared to the surrounding healthy tissues (P < 0.05). IRAK1 and IRF7 were expressed in a small amount in the epidermal layer with higher positive rates of expression than in the surrounding healthy tissues (P < 0.05), while the positive rates of TLR7 and TLR9 expression in the epidermal layer were not statistically different from those in the surrounding healthy tissues (P > 0.05).Conclusion: PDC and TLR7/9-MyD88-IRAKs pathways are actively expressed in chronic eczema lesions and may be involved in pathogenesis and disease progression.Keywords: eczema, plasmacytoid dendritic cells, toll-like receptor 7, toll-like receptor 9, immunohistochemistry