ABSTRACT
Objective To investigate the relationship of skin-resident memory T cells (Trm cells) with the skin lesions in systemic lupus erythematosus (SLE) so as to deepen our understanding of the pathogenesis of skin lesions in SLE. Methods Peripheral blood and skin samples were collected from SLE patients and matched healthy volunteers. The percentages of effector memory T cells (Tem cells) and effcctor T cells (Teff cells) from peripheral blood were analyzed by flow cytometry. By using direct immunofluoresence, we detected the presence of immune complex,which deposited on the basement membrane of normal appearance skin from SLE patients or healthy individuals. Immunohistochemical staining was performed to detect the two characteristic surface markers of tissue-resident memory T lymphocytes,CD69 and CD103 and to analyze the expression of these T lymphocytes within skins from SLE patients or healthy volunteers. Data analysis was performed using t test. P<0.05 was considered statistically significant. Results As compared with control individuals,the proportions of CD4+Tem (12.6±3.4 vs 8.2±2.5,t=-3.15,P<0.05),CD4+Teff (2.5±1.5 vs 1.3± 0.8,t=-2.79,P<0.05)、CD8+Tem(15.3±3.6 vs 7.0±3.0,t=-6.22,P<0.05)and CD8+Teff cells(13.1±5.4 vs 3.7± 1.3,F=-7.36,P<0.05)in T cell subset were significantly increased. Also,the proportions of CD4+Tem(8.4±2.7 vs 5.8±2.0,t=-2.74,P<0.05),CD4+Teff (1.6±1.0 vs 0.8±0.5,t=-2.84,P<0.05),CD8+Tem (10.4±3.6 vs 5.3±2.4, t=-4.03, P<0.05) and CD8+Teff cells (8.2±4.1 vs 2.6±0.8, t=-6.15, P<0.05) in peripheral blood were increased as well. By direct immunofluorescence,we noticed the deposition of immunoglobulin IgA, IgM and complement C3 on the basement membrane zone of skins from SLE patients but not on heanlhy individuals. The amount of infiltrated lymphocytes in skin samples from SLE patients were significantly iecreased compared to that of healthy individuals,and the quantities of CD4, CD8 and CD103 positive T cells from SLE skin samples were all increased by various degrees than that of controls. Conclusion Skin-resident memory T cells may be involved in the pathogenesis of skin lesions in SLE.