目的 探究CD4⁺T细胞极化在肾间质纤维化炎症反应过程中的作用。方法 采用单侧输尿管结扎（UUO）大鼠模型，24只SD大鼠随机分为假手术对照组、UUO 3 d组和UUO 7 d组。利用H-E、MASSON染色技术观察肾组织纤维化程度，采用免疫磁珠分选外周血中CD4⁺T细胞并在CD3/28-IL-2的刺激下培养3 d，流式细胞术比较UUO大鼠和正常大鼠CD4⁺T细胞体外增殖、极化情况，PCR法检测转录因子的差异。结果 UUO造模后肾组织纤维化程度以及淋巴细胞的浸润程度加重，CD4⁺T细胞增殖增加（P<0.05）。造模组IL17A⁺CD4⁺T/CD4⁺T细胞比例和CD4⁺CD25⁺Foxp3⁺/CD4⁺T比例较正常组表达增加（P<0.05）。检测CD4⁺T各亚群上游转录因子，发现促炎基因RORγt、T-bet随造模时间显著增加，抑炎基因Gata-3下调，调节炎症的基因Foxp3上调（P<0.05）。结论 肾间质纤维化会促使CD4⁺T细胞增殖并释放多种促炎因子，加重炎症反应，使病情恶化。

Objective To explore the effects of polarization of CD4⁺T cells during the course of inflammatory reaction of renal interstitial fibrosis. Methods Twenty-four SD rats that underwent unilateral ureteral obstruction (UUO) were randomly divided into the sham-operation group, UUO 3 d group, and UUO 7 d group. The degree of fibrosis of renal tissue was observed by H-E and MASSON staining. CD4⁺T cells in peripheral blood were separated by immunomagnetic beads and cultured for 3 d under the stimulation of CD3/28-IL-2. The in vitro proliferation and polarization of CD4⁺T cells of rats with UUO and normal rats were compared by flow cytometry. The difference of transcription factor was detected by PCR. Results The fibrosis of renal tissue and infiltration of lymphocytes aggravated and the proliferation of CD4⁺T cells increased after UUO (P<0.05). Compared with normal rats, IL17A⁺CD4⁺T/CD4+T and CD4⁺CD25⁺Foxp3⁺/CD4⁺T ratios of rats with UUO were higher (P<0.05). Detection of upstream transcription factors of CD4⁺ T subsets showed that pro-inflammatory genes RORγt and T-bet significantly increased with time after UUO; anti-inflammation gene Gata-3 decreased; and inflammation regulation gene Foxp3 increased (P<0.05). Conclusion Renal interstitial fibrosis can promote CD4⁺T cell to proliferate and release various pro-inflammatory factors and aggravate inflammatory reaction and disease.