[Effects of interleukin-35 on the balance of helper T cell 17/regulatory T cell in peripheral blood of patients with oral lichen planus].

To investigate the effects of exogenous interleukin (IL)-35 on the balance of helper T cell 17 (Th17) and regulatory T cell (Treg) in peripheral blood of patients with oral lichen planus (OLP). Totally 12 peripheral blood samples of OLP patients (OLP group, one male and 11 female, 26-68 years old; four cases of reticular OLP and eight cases of erosive OLP) were collected from patients of Department of Oral Mucosal Specialist of the Affiliated Hospital of Guizhou Medical University from October to December 2016. During the same period, thirteen normal peripheral blood samples were collected from the Physical Examination Center of the Affiliated Hospital of Guizhou Medical University (normal control group, one male and 12 female, 20-68 years old). The peripheral blood mononuclear cells (PBMC) were extracted in sterile condition and CD4+ T cells were sorted by flow cytometry (FCM). Quantitative real-time PCR (qPCR) technique was used to detect the mRNA expression levels of retinoid-related orphan nuclear γt (RORγt) and forkhead box3 (Foxp3). The CD4+ T cells were divided into experimental group and control group. The CD4+ T cells of experimental group were cultured by adding rhIL-35, and the CD4+ T cells of control group were cultured with the same volume of phosphate buffered saline (PBS). After the completion of the culture, the cells were collected. The expression levels of the same factors were detected by qPCR. The expression [((25), (75))] of Foxp3 [0.15 (0.09, 0.30)] and RORγt mRNA [1.04 (0.45, 2.15)] in the CD4+ T cells of OLP were significantly higher than those in normal control group [0.04 (0.02, 0.06), 0.10 (0.05, 0.11)] (-4.134, <0.01; 3.699, <0.01). The ratio of ROR γt/Foxp3 mRNA in OLP group [6.22(3.67, 15.34)] was higher than that in normal control group [2.50 (1.24, 5.23)] (-2.665, 0.007). In the CD4+ T cells of OLP patients, the expression of Foxp3 mRNA in the experiment group [0.40 (0.21, 1.22)] was higher than that in the control group [0.15 (0.11, 0.26)](-2.510, 0.012), and the expression of ROR γt mRNA between two groups showed no significant difference (>0.05). The ROR γt/Foxp3 mRNA ratio [3.44 (1.55, 8.16)] of the experiment group was lower than that in the control group [6.22 (4.43, 12.21)] (-2.746, 0.006). There was a Th17/Treg imbalance with predominated by Th17 cells in the peripheral blood of patients with OLP. Exogenous rhIL-35 had an immunomodulatory effect on the balance of Th17/Treg.