Moxibustion Regulates the Expression of T Cells in Rheumatoid Arthritis Through Tim-3/Gal-9 Signaling Pathway

To observe the effects of moxibustion on T cells and T cell immunoglobulin and mucin-domain-containing molecule-3/galectin-9 (Tim-3/Gal-9) pathway in rats with rheumatoid arthritis (RA). To further explore the possible anti-inflammatory mechanism of moxibustion in the treatment of RA. Thirty Sprague Dawley rats were randomly divided into three groups, including a control group, an RA model group, and a moxibustion group. An RA model was created through the injection of Freund's complete adjuvant. In the moxibustion group, rats were treated with moxibustion at acupoints of "Shenshu" and "Zusanli." A total of three courses of treatment were conducted. Then the thickness of foot pad was measured, joint pathological changes were observed by hematoxylin-eosin (HE) staining, the proportion of CD4⁺T and CD8⁺T in peripheral blood was detected by flow cytometry, the expression levels of Tim-3 and Gal-9 in synovium were detected by polymerase chain reaction (PCR), and the expressions of CD4⁺T and CD8⁺T in synovium were detected by immunofluorescence. HE staining showed that the synovial tissue of the control group was smooth and neatly arranged without inflammatory cell infiltration. In the model group, the joint space was narrowed, the synovial tissue had congestion and edema, and a large number of inflammatory cells infiltrated. Compared with the model group, in the moxibustion group, the joint space narrowed with synovium hyperemia and edema, and the level of inflammatory cell infiltration decreased. Flow cytometry showed that compared with the model group, CD4⁺T expression in the moxibustion group was downregulated, while CD8⁺T expression was upregulated. PCR results showed that compared with the model group, the expressions of Tim-3 and Gal-9 in the moxibustion group were upregulated. Immunofluorescence results showed that compared with the model group, CD4⁺T expression in the moxibustion group was decreased, while CD8⁺T expression was increased. The results demonstrate that moxibustion not only suppressed the expression of CD4⁺T but also promoted the expression of CD8⁺T. The anti-inflammatory effect of moxibustion may be related to the regulation of T cell expression through the Tim-3/Gal-9 signaling pathway.