## 3 Results
### Effect of PMT on T Lymphocyte Populations in the Immunosuppressed Mice  
T lymphocytes, critical regulators of immune responses, were analyzed to evaluate the immunomodulatory effects of PMT in the CPA-induced immunosuppression mouse model. Flow cytometric analysis revealed significant alterations in the percentages of CD3e\({}^{+}\)CD4\({}^{+}\) T helper cells and CD3e\({}^{+}\)CD8\({}^{+}\) T cytotoxic cells among the groups (Figure 4A-D). In the CPA group, percentages of the CD3e\({}^{+}\)CD4\({}^{+}\) and CD3e\({}^{+}\)CD8\({}^{+}\) cells were markedly reduced compared to the normal group. Treatment with 100 and 200 mg/kg PMT significantly reversed these effects. In the PMT200 group, proportions of the CD3e\({}^{+}\)CD4\({}^{+}\) and CD3e\({}^{+}\)CD8\({}^{+}\) T cells were significantly elevated, increasing approximately 1.5-fold and 2-fold, respectively, compared to the CPA group. Additionally, to further assess the impact of PMT on lymphocyte activation, CD25 expression was analyzed via flow cytometry (Supplementary Figure S1). CD25 was significantly reduced in the CPA group compared to the normal group, indicating impaired lymphocyte activation. However, PMT treatment restored CD25 expression in a manner proportional to the dose, with both 100 mg/kg and 200 mg/kg PMT groups showing a significant increase in the percentage of CD25\({}^{+}\) lymphocytes. The PMT200 group, in particular, exhibited the most pronounced recovery, suggesting that PMT enhances lymphocyte proliferation under immunosuppressive conditions.  
Figure 3: Effect of PMT on thymus size, weight, histology, and thymus index in the CPA-treated mice. (**A**) Representative thymus tissue images from each group at 14 days. White scale bar = 200 \(\upmu\)m. (**B**) Quantitative analysis of thymus weight across the different treatment groups. (**C**) Histological evaluation of thymic architecture using H&E staining. Black scale bar = 200 \(\upmu\)m, red scale bar = 40 \(\upmu\)m. (**D**) Thymus index (thymus weight/body weight ratio) across different treatment groups. Data are presented as the means \(\pm\) SEM (n = 6). Statistical significance was determined using one-way ANOVA followed by [PERSON]’s post hoc test. Note: \({}^{***}\)_p_ \(<\) 0.0001 vs. the normal group; \({}^{**}\)_p_ \(<\) 0.01 and \({}^{***}\)_p_ \(<\) 0.001 vs. the CPA group.  
Immunohistochemical analysis of CD3+ T lymphocytes in the thymus corroborated these findings (Figure 4E). The proportion of CD3+ lymphocytes in the CPA group was significantly lower than that in the normal group, indicating reduced T cell activity due to immunosuppression (Figure 4F). Treatment with 100 and 200 mg/kg PMT effectively increased the proportion of CD3+ lymphocytes in the thymus, reflecting enhanced T cell activity. Notably, the PMT200 group showed the highest levels of CD3+ lymphocytes, demonstrating significant improvement and suggesting a response that correlates with the administered dose. Overall, these results highlight the immunomodulatory effects of PMT, which effectively regulated T lymphocyte subsets, enhanced T cell activity, and improved immune function in CPA-induced immunosuppression mice.