目的 观察多房棘球蚴感染晚期小鼠肝T细胞的NK1.1表达变化，分析NK1.1表达对T细胞功能的影响。 方法 C57BL/6N小鼠随机分为对照组和感染组。感染组小鼠经肝门静脉注射2 000个多房棘球蚴原头节，对照组注射等体积生理盐水。感染后36周取肝组织，苏木素-伊红（HE）染色观察肝组织病理变化，天狼星红和Masson染色观察肝组织纤维化情况。收集肝淋巴细胞，流式细胞术检测小鼠肝CD4⁺ T细胞和CD8⁺ T细胞占比，并检测不同T细胞的NK1.1、颗粒酶B（GrB）、穿孔素、γ干扰素（IFN-γ）和白细胞介素-17（IL-17）表达变化。采用SPSS 25.0软件进行统计学分析，两组间比较采用独立样本t检验。 结果 感染多房棘球蚴36周后，HE染色显示感染组小鼠肝组织内可见具有生发层结构的病灶，周围出现大量炎性细胞浸润；Masson染色和天狼星红染色显示感染组小鼠肝组织纤维化明显。流式结果显示，感染组小鼠肝脏的CD4⁺ T和CD8⁺ T细胞的占比分别为（32.0 ± 6.0）%、（42.0 ± 13.9）%，与对照组的（36.6 ± 9.0）%、（50.2 ± 5.2）%差异均无统计学意义（t = 1.068、1.446，均P > 0.05）。感染组NK1.1⁺CD4⁺ T细胞占CD4⁺ T细胞的（30.0 ± 14.5）%，低于对照组NK1.1⁺CD4⁺ T细胞的（69.0 ± 10.7）%（t = 5.573，P < 0.01）和感染组NK1.1^-CD4⁺ T细胞的（51.6 ± 10.8）%（t = 2.920，P < 0.05）。感染组NK1.1⁺CD8⁺ T细胞占CD8⁺ T细胞的（22.0 ± 12.9）%，低于对照组NK1.1⁺CD8⁺ T细胞的（43.6 ± 5.9）%（t = 3.999，P < 0.01）和感染组NK1.1^-CD8⁺ T细胞的（64.0 ± 13.6）%（t = 5.496，P < 0.01）。感染组小鼠分泌GrB、IFN-γ和IL-17的NK1.1⁺CD4⁺ T细胞占比分别为（4.8 ± 2.8）%、（6.8 ± 6.0）%和（6.9 ± 5.2）%，均低于对照组的（12.6 ± 4.8）%、（23.6 ± 7.3）%和（22.1 ± 7.1）%（t = 3.462、4.171、4.124，均P < 0.01）；分泌GrB、IFN-γ和IL-17的NK1.1⁺CD8⁺ T细胞占比分别为（1.5 ± 0.9）%、（5.3 ± 2.7）%和（3.7 ± 2.3）%，均低于对照组的（6.0 ± 2.7）%、（18.1 ± 9.5）%和（16.9 ± 9.3）%（t = 3.861、3.196、3.361，P < 0.01、0.05、0.01）。感染组分泌穿孔素的NK1.1⁺CD4⁺ T和NK1.1⁺CD8⁺ T细胞占比分别为（3.0 ± 1.3）%和（2.7 ± 1.2）%，与对照组的（2.3 ± 1.2）%和（2.1 ± 1.6）%差异均无统计学意义（t = 1.027、0.717，均P > 0.05）。感染组分泌GrB的NK1.1^-CD4⁺ T细胞占比为（6.7 ± 2.1）%，高于NK1.1⁺CD4⁺ T细胞（t = 2.629，P < 0.05）；分泌IFN-γ的NK1.1^-CD8⁺ T细胞占比为（13.7 ± 9.2）%，高于NK1.1⁺CD8⁺ T细胞（t = 2.609，P < 0.05）；分泌IL-17的NK1.1^-CD8⁺ T细胞占比为（1.0 ± 0.4）%，低于NK1.1⁺CD8⁺ T细胞（t = 2.740，P < 0.05）。 结论 多房棘球蚴感染晚期小鼠肝组织中NK1.1⁺CD4⁺ T细胞、NK1.1⁺CD8⁺ T细胞数量均减少，分泌的GrB、IFN-γ、IL-17降低，导致NK1.1⁺ T细胞呈现免疫耗竭状态。

Objective To observe the changes in NK1.1 expression of liver T cells in the advanced stage of mice infected with Echinococcus multilocularis, and analyze the effect of NK1.1 expression on liver T cells’ function. Methods C57BL/6N mice were assigned into the infection group and the control group randomly. Mice in the infection group were injected with 2 000 E. multilocularis protoscoleces through hepatic portal vein, while mice in the control group injected with the same volume of normal saline. The livers were collected at the advanced stage of infection (36 weeks post-infection). The pathological changes of the liver tissues were observed by hematoxylin-eosin (HE) staining, and the degree of live fibrosis was observed by Masson staining and Sirius red staining. The lymphocytes were collected and the flow cytometry was performed to detect the proportions of CD4⁺ T and CD8⁺ T cells. The expression changes of NK1.1, granzyme B (GrB), perforin, interferon-γ (IFN-γ) and interleukin-17 (IL-17) in different T cells were also detected. SPSS 25.0 software was used for statistical analysis, and an independent sample t-test was used to compare the mean between the two groups. Results HE staining showed that lesions with germinal layer structure were formed in the livers of mice in the infection group 36 weeks post-infection, with infiltration of inflammatory cells in surrounding tissues, and results of Masson staining and Sirius red staining showed the significant hepatic fibrosis. Flow cytometry results showed the proportions of CD4⁺ T and CD8⁺ T cells in the liver of mice in the infection group 36 weeks post-infection were (32.0 ± 6.0)% and (42.0 ± 13.9)%, respectively, which were (36.6 ± 9.0)% and (50.2 ± 5.2)% in the control group, with no significant differences (t = 1.068, 1.446, both P > 0.05). The proportion of NK1.1⁺CD4⁺ T cells in the infection group was (30.0 ± 14.5)%, which was lower than NK1.1⁺CD4⁺ T cells in the control group [(69.0 ± 10.7)%] (t = 5.573, P < 0.01) and NK1.1^-CD4⁺ T cells in the infection group [(51.6 ± 10.8)%] (t = 2.920, P < 0.05). The proportion of NK1.1⁺CD8⁺ T cells in the infection group was (22.0 ± 12.9)%, which was lower than NK1.1⁺CD8⁺ T cells in the control group [(43.6 ± 5.9)%] (t = 3.999, P < 0.01) and NK1.1^-CD8⁺ T cells in the infection group [(64.0 ± 13.6)%] (t = 5.496，P < 0.01). The proportions of NK1.1⁺CD4⁺ T cells that secreted GrB, IFN-γ and IL-17 in the infection group were (4.8 ± 2.8)%, (6.8 ± 6.0)% and (6.9 ± 5.2)%, respectively, which were lower than those in the control group [(12.6 ± 4.8)%, (23.6 ± 7.3)% and (22.1 ± 7.1)%] (t = 3.462, 4.171, 4.124, all P < 0.01). The proportions of NK1.1⁺CD8⁺ T cells that secreted GrB, IFN-γ and IL-17 in the infection group were (1.5 ± 0.9)%, (5.3 ± 2.7)% and (3.7 ± 2.3)%, respectively, which were lower than those in the control group [(6.0 ± 2.7)%, (18.1 ± 9.5)% and (16.9 ± 9.3)%] (t = 3.861, 3.196, 3.361, P < 0.01, 0.05, 0.01). The proportions of NK1.1⁺CD4⁺ T and NK1.1⁺CD8⁺ T cells that secreted perforin in the infection group were (3.0 ± 1.3)% and (2.7 ± 1.2)%, respectively, which were (2.3 ± 1.2)% and (2.1 ± 1.6)% in the control group, with no significant differences (t = 1.027, 0.717, both P > 0.05). In the infection group, the proportion of NK1.1^-CD4⁺ T cells secreted GrB was (6.7 ± 2.1)%, which was higher than NK1.1⁺CD4⁺ T cells (t = 2.629, P < 0.05); the proportion of NK1.1^-CD8⁺ T cells secreted IFN-γ was (13.7 ± 9.2)%, which was higher than NK1.1⁺CD8⁺ T cells (t = 2.609, P < 0.05); the proportion of NK1.1^-CD8⁺ T cells secreted IL-17 was (1.0 ± 0.4)%, which was lower than NK1.1⁺CD8⁺ T cells (t = 2.740, P < 0.05). Conclusion The number of NK1.1⁺CD4⁺ T and NK1.1⁺CD8⁺ T cells decreased in the liver of mice infected with E. multilocularis in the advanced stage, and the secretion of GrB, IFN-γ and IL-17 were weakened, which indicated the existence of immune depletion of NK1.1⁺ T cells.