Experimental study on the regulatory effect ofQinggan Dongyin on T lymphocyte homeostasis in MRL/lpr mice.

Systemic lupus erythematosus (SLE) is an autoimmune disease marked by autoantibody overproduction and increased infection risk, even with current treatments. Dysregulated T lymphocyte homeostasis contributes to SLE progression, prompting exploration of immunomodulatory therapies. This study evaluated the effects of Qinggan Dongyin (QGDY), a compound of tradi-tional Chinese medicine, in a murine SLE model. Twelve female MRL/lpr mice were randomly divided into model and QGDY treatment groups (n=6 each), with age-matched C57BL/6 mice as controls. QGDY (5 mL/kg/day) was ad-ministered via gavage for two weeks; controls received saline. Flow cytometry analyzed T cell subsets (CD4+, CD8+, Treg, Th1, Th2, Th17), ELISA measured plasma cytokines (IFN-γ, IL -6, TNF-α, IL -17A, TGF-β), HE staining assessed lung and kidney pathology, and qPCR evaluated cGAS and STING expression. Compared to the model group, QGDY significantly restored T cell balance by increasing CD4+, CD8+, and Treg cells and reducing Th1, Th2, and Th17 cells (p<0.01). QGDY also lowered pro-inflammatory cytokine levels (p<0.05), im-proved organ histopathology, and normalized elevated cGAS and STING expres-sion (p<0.01). These findings indicate that QGDY exerts immunomodulatory effects in SLE, suggesting therapeutic potential through the regulation of T cell function and inflammatory signalling pathways.