To be elucidated. Activation of adjacent fibroblasts by CD4+ T cellsTo be elucidated. Activation of

To be elucidated. Activation of adjacent fibroblasts by CD4+ T cells
To be elucidated. Activation of adjacent fibroblasts by CD4+ T cells is thought to be critical to the pathological fibrosis in SSc [1,4,5]. The mechanism of CD4+ T-cell-induced fibrosis merits further examination. Because CD11a plays a rolein cell contact between activated CD4+ T cells and other cells, including fibroblasts, a question is raised whether CD11a overexpressed on CD4+ T cells activates fibroblasts or enhances collagen synthesis. The expression of COL1A2 mRNA in fibroblasts co-cultured with SSc CD4+ T cells and normal CD4+ T cells was examined. SSc CD4+ T cells have a more potent ability to activate fibroblasts than normal CD4+ T cells; this increases the rate of COL1A2 mRNA expression. The current results are generally consistent with those of previous studies in which inflammatory cells, especially CD4+ T cells, provide important stimuli that drive collagen synthesis in fibroblasts from patients with SSc [4,5]. CD11a is involved in this process because the anti-CD11a blocking antibody markedly reduced the COL1A2 mRNA expression in fibroblasts co-cultured with SSc CD4+ T cells. Fibroblasts were also co-cultured with 5-azaC-treated and control CD4+ T cells. Here, 5azaC-treated CD4+ T cells were found to activate PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28549975 fibroblasts to foster COL1A2 mRNA production more strongly than in control CD4+ T cells. This production was inhibited by anti-CD11a antibody, as expected. The current work is the first to demonstrate the direct association of CD11a overexpressed on SSc CD4+ T cells with excessive expression of COL1A2 by fibroblasts, a considerably important process in the pathogenesis of SSc.Conclusions In conclusion, it is demonstrated herein that CD11a is overexpressed by the demethylation of CD11a promoter regions in SSc CD4+ T cells resulting in increased proliferation of CD4+ T cells, IgG overproduction by B cells, and excessive collagen synthesis by fibroblasts. Current data provide a new insight into the pathogenesis of SSc and a therapeutic approach via methylation status of CD11a in CD4+ T cells. MethodsSubjectsEighteen SSc patients (10 women and 8 men, mean ?SD age 43 ?6 years) were recruited from the clinic of the Department of Dermatology, the Second Xiangya Hospital at the Central South University. All patients met the American College of Rheumatology criteria for SSc [43]. Fifteen healthy subjects (8 women and 7 men, mean ?SD age 40 ?5 years) were recruited from the medical staff at the Second Xiangya Hospital. Patients and healthy subjects were age-, race-, and sex-matched in all experiments. A skin thickening assessment was evaluated using the modified Rodnan total skin score and disease activity was assessed with the SDAI [44,45]. This study was approved by the Human Ethics Committee of the Central South University Xiangya Medical College. Signed informed consent was obtained from all subjects. The clinical andWang et al. Clinical Epigenetics 2014, 6:25 http://www.clinicalepigeneticsjournal.com/content/6/1/Page 9 oflaboratory characteristics of the patients are shown in Table 1.Cell isolation and culture CD4+ T cell and B cell isolation80 confluence. The fibroblasts between passages 3 and 6 in monolayer culture were used for the experiment. Fibroblasts were evaluated using immunocytochemical staining for cytokeratin and vimentin.Flow cytometric analysisPBMCs were isolated by Ficoll-Hypaque density gradient ChaetocinMedChemExpress Chaetocin centrifugation (Hengxin Chemical Reagent Co, Ltd., Shanghai, China) and CD4+ T cells and B cells were isolate.