Catgut Implantation at Acupoints has an Immunosuppressive Effect on Autoimmune Uveitis by Reducing Th1/Th17 Lymphocytes

Catgut implantation at acupoints (CIA) has been applied as medical treatment for autoimmune diseases. Yet, its effect and mechanism of this therapy on autoimmune uveitis is still unknown. Here we aimed to explore the immunoregulatory effect of CIA in the experimental autoimmune uveitis (EAU) rat model. Lewis rats were induced with EAU by injecting IRBP1177-1191 peptide, and subsequently treated with CIA. In the CIA group, delayed mild inflammation was observed with alleviated infiltration of lymphocytes and ocular damage. Flow cytometry showed significant decrease in Th17 lymphocytes at Day 9, 13, and 18 post-immunizations (P<0.05) after CIA. The Th1 lymphocytes were also significantly decreased at Day 13 and 18 post-immunizations (P<0.05) in the CIA group. IL-17 and IFN-gamma mRNA levels were notably decreased at Day 9, 13 and 18 post-immunizations (P<0.05) after CIA. Serum IL-17 and IFN-gamma levels in the CIA group were significantly decreased at Day 9, 13 and 18 post-immunizations ( P<0.05). Ocular inflammation was markedly inhibited after catgut implantation at Pishu (BL20) and Shenshu (BL23) acupoints in the EAU-induced rats. In summary, this study revealed that CIA could reduce Th1 and Th17 lymphocytes and the expression of IFN-gamma and IL-17 in the EAU rat model, suggesting its potential in uveitis treatment.