Effect of pachyman polysaccharides on Th17/Treg balance in systemic lupus erythematosus patients

AIM: To investigate the immunomodulatory effect of pachyman polysaccharides (PPS) on T helper 17 cell (Th17)/regulatory T cell (Treg) balance in the peripheral blood of systemic lupus erythematosus (SLE) patients. METHODS: The CD4⁺ T cells were isolated from the peripheral blood samples obtained from 45 SLE patients and 35 healthy controls enrolled in our study using magnetic bead separation method. The proportions of Th17 and Treg cells were measured by flow cytometry. The CD4⁺ T cells from SLE patients and healthy controls were treated with PPS. The cytoto-xicity of PPS was evaluated by detecting cell viability with MTT assay. The contents of interleukin-17 (IL-17), IL-6, IL-10 and transforming growth factor-β (TGF-β) were measured by ELISA. The expression of retinoid-related orphan receptor γt (RORγt) and forkhead box protein P3 (Foxp3) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. RESULTS: The Th17 cells were significantly elevated, while Treg cells were obviously decreased in the SLE patients compared with the healthy control group (P<0.05). Compare with control group, the contents of IL-17 and IL-6 were decreased, while the contents of IL-10 and TGF-β were increased (P<0.05). The expression of RORγt at mRNA and protein levels was down-regulated and the expression of Foxp3 was up-regulated (P<0.05). The ratio of Th17/Treg was decreased in 100 μg/L nontoxic PPS-treated CD4⁺ T cells isolated from the SLE patients (P<0.05). CONCLUSION: PPS treatment inhibits Th17 cells and elevates Treg cells in the CD4⁺ T cells isolated from SLE patients, which may have a therapeutic effect on SLE patients.