目的 分析多房棘球蚴感染小鼠在不同感染时期的肝纤维化进展情况和肝脏固有淋巴细胞（ILC）及其亚型的比例动态变化，探讨多房棘球蚴感染所致肝纤维化与固有淋巴细胞的相关性，为揭示多房棘球蚴感染所致肝纤维化的免疫调节机制提供理论基础。方法 将BALB/c小鼠随机分为感染组和对照组（每组18只），感染组每鼠注射1 500个多房棘球蚴原头节，分别于感染后30、90、180 d安乐处死。采用苏木精-伊红（HE）染色和Masson染色观察肝组织结构变化、炎症程度和胶原沉积情况；采用免疫荧光染色检测α-平滑肌肌动蛋白（α-SMA）、转移生长因子β1（TGF-β1）、Collagen Ⅰ、Collagen Ⅲ等纤维化相关蛋白的表达情况；利用流式细胞术检测肝脏ILC在肝脏免疫细胞中的占比及其亚型（ILC1、ILC2、ILC3）在总ILC中的比例变化情况；实时荧光定量PCR检测IL-33的相对表达量。采用Pearson相关分析探讨ILC各亚型与纤维化指标的相关性。结果 多房棘球蚴感染30 d后，小鼠肝脏出现囊泡样病灶，病灶随感染时间延长逐渐增大，并侵袭周围的肝组织导致炎症发生，甚至出现纤维化病变。HE染色结果显示，炎症随感染时间增加而加重，感染后180 d纤维间隔逐渐形成。Masson染色结果显示，感染后90、180 d胶原面积占比分别为（37.26 ± 7.83）%、（55.36 ± 8.21）%，相比同期对照组[（1.57 ± 1.17）%、（0.83 ± 0.73）%]升高（t = 7.80、11.47，均P < 0.01）。免疫荧光结果显示，α-SMA、TGF-β1、Collagen Ⅰ及Collagen Ⅲ在感染组中的荧光强度与4’，6-二脒基-2-苯基吲哚（DAPI）的比值分别为1.08%、0.94%、3.33%和1.55%，均高于对照组（0.51%、0.12%、0.20%、0.62%）（t = 4.62、5.42、4.12、5.54，均P < 0.01）。流式细胞术分析显示，感染后30 d，感染组小鼠表达CD45.2⁺的肝脏白细胞中ILC占比为（2.54 ± 0.43）%，与对照组的（2.29 ± 0.31）%相比差异无统计学意义（t = 0.91，P > 0.05）；感染后90 d，感染组ILC占比为（1.16 ± 0.51）%，低于对照组的（1.88 ± 0.31）%（t = 2.69，P < 0.05）；感染后180 d，感染组ILC占比为（0.56 ± 0.13）%，高于对照组的（0.31 ± 0.07）%（t = 3.02，P < 0.05）。在ILC亚群中，感染后90、180 d感染组小鼠ILC1占ILC的比例分别为（61.22 ± 4.38）%和（11.11 ± 3.61）%，低于对照组的（75.96 ± 4.81）%和（47.50 ± 4.95）%（t = 5.067、10.29，P均 < 0.01），与Masson染色胶原面积比呈负相关（r < 0，P < 0.05）；感染后180 d，感染组ILC2占比为（78.50 ± 4.10）%，高于对照组的（33.23 ± 4.57）%（t = 12.78，P < 0.01），与Masson染色胶原面积比呈正相关（r = 0.72，P < 0.05）；感染后30、90、180 d，感染组ILC3占比分别为（5.58 ± 2.37）%、（2.90 ± 0.84）%和（4.07 ± 2.94）%，与同期对照组[（6.08 ± 0.83）%、（2.66 ± 0.68）%和（5.24 ± 3.74）%]相比差异均无统计学意义（t = 0.40、0.49、0.43，P均 > 0.05），与纤维化指标间未显示显著相关性。肝组织IL-33 mRNA的表达在感染后30 d（1.37 ± 0.28）与对照组（1.03 ± 0.17）相比差异无统计学意义（t = 1.06，P > 0.05）；感染后90 d（2.88 ± 0.49）与对照组（0.74 ± 0.14）相比升高（t = 3.62，P < 0.05）；感染后180 d（1.55 ± 0.31）与对照组（1.06 ± 0.26）相比差异无统计学意义（t = 1.10，P > 0.05）。结论 多房棘球蚴感染可致小鼠肝纤维化并诱导ILCs及其亚型在肝脏免疫细胞中的比例改变，其中ILC2在感染晚期显著上调，可能参与了调控肝星状细胞活化及促进纤维化进程。

Objective To investigate the progression of hepatic fibrosis and the dynamic changes in the proportions of innate lymphoid cells (ILCs) and their subtypes in mice infected with Echinococcus multilocularis at various stages, and to examine the association between E. multilocularis-induced hepatic fibrosis and ILCs, so as to provide the theoretical basis for unraveling the immunoregulatory mechanisms underlying E. multilocularis-induced hepatic fibrosis. Methods BALB/c mice were randomly divided into an infection group and a control group (18 mice in each group). Each mouse in the infection group was injected with 1 500 E. multilocularis protoscoleces, and mice were euthanized 30, 90, and 180 days post-infection. Changes in the structure of liver tissues, inflammation and collagen deposition were observed using hematoxylin and eosin (HE) staining and Masson’s trichrome staining, and the expression of fibrosis-related proteins was quantified using immunofluorescence staining, including α-smooth muscle actin (α-SMA), transforming growth factor (TGF)-β1, Collagen Ⅰ, and Collagen Ⅲ. The proportion of ILCs in liver immune cells and the proportions of ILC subtypes (ILC1, ILC2, ILC3) in total ILCs were estimated using flow cytometry, and the relative IL-33 expression was quantified using quantitative Real-time PCR (qPCR) assay. The associations between ILC subtypes and fibrosis-related indicators were examined using Pearson correlation analysis. Results Vesicle-like lesions were seen in mouse livers 30 days post-infection with E. multilocularis, which gradually enlarged over time, and the lesions invaded surrounding liver tissues, leading to inflammation and even fibrotic lesions. HE staining showed aggravation of inflammation over time post-infection, and fiber spacing gradually formed 180 days post-infection. Masson’s trichrome staining showed higher proportions of collagen areas 90 days [(37.26 ± 7.83)% vs. (1.57 ± 1.17)%; t = 7.80, P < 0.01] and 180 days post-infection [(55.36 ± 8.21)% vs. (0.83 ± 0.73)%; t = 11.47, P < 0.01] than in controls. Immunofluorescence staining revealed higher ratios of the fluorescence intensity of α-SMA (1.08% vs. 0.51%; t = 4.62, P < 0.01), TGF-β1 (0.94% vs. 0.12%; t = 4.62, P < 0.01), Collagen Ⅰ (3.33% vs. 0.20%; t = 4.62, P < 0.01), and Collagen Ⅲ to 4', 6-diamidino-2-phenylindole (DAPI) (1.55% vs. 0.62%; t = 5.54, P < 0.01) in the infection group than in the control group, and flow cytometry showed a higher proportion of ILC in mouse liver leukocytes expressing CD45.2⁺ cells in the infection group than in the control group 30 days post-infection [(2.54 ± 0.43)% vs. (2.29 ± 0.31)%; t = 0.91, P > 0.05], a lower proportion of ILCs in the infection group than in the control group 90 days post-infection [(1.16 ± 0.51)% vs. (1.88 ± 0.31)%; t = 2.69, P < 0.05], and a higher proportion of ILCs in the infection group than in the control group 180 days post-infection [(0.56 ± 0.13)% vs. (0.31 ± 0.07)%; t = 3.02, P < 0.05]. The proportions of ILC1 in ILCs were lower in mice in the infection group than in the control group 90 [(61.22 ± 4.38)% vs. (75.96 ± 4.81)%; t = 5.067, P < 0.01] and 180 days post-infection [(11.11 ± 3.61)% vs. (47.50 ± 4.95)%; t = 10.29, P < 0.01], and negatively correlated with the ratio of collagen areas as revealed by Masson’s trichrome staining (r < 0, P < 0.05). The proportion of ILC2 in ILCs were higher in mice in the infection group than in the control group 180 days post-infection [(78.50 ± 4.10)% vs. (33.23 ± 4.57)%; t = 12.78, P < 0.01], and positively correlated with the ratio of collagen areas as revealed by Masson’s trichrome staining (r = 0.72, P < 0.05). There were no significant differences between the infection and control groups in terms of the proportion of ILC3 in ILCs 30 [(5.58 ± 2.37)% vs. (6.08 ± 0.83)%; t = 0.40, P > 0.05], 90 [(2.90 ± 0.84)% vs. (2.66 ± 0.68)%; t = 0.49, P > 0.05] and 180 days post-infection [(4.07 ± 2.94)% vs. (5.24 ± 3.74)%; t = 0.43, P > 0.05], and no significant associations were detected between the proportion of ILC3 in ILCs and fibrosis-related parameters. qPCR assay quantified no significant difference in the IL-33 mRNA expression in mouse liver tissues between the infection (1.37 ± 0.28) and control groups (1.03 ± 0.17) 30 days post-infection (t = 1.06, P > 0.05), higher IL-33 mRNA expression in the infection group (2.88 ± 0.49) than in the control group (0.74 ± 0.14) 90 days post-infection (t = 3.62, P < 0.05), and no significant difference in the IL-33 mRNA expression between the infection (1.55 ± 0.31) and control groups (1.06 ± 0.26) 30 days post-infection (t = 1.10, P > 0.05). Conclusion E. multilocularis infection may induce hepatic fibrosis in mice and alter the proportions of ILCs and their subtypes in hepatic immune cells. Notably, ILC2 expression is significantly upregulated at late stage of E. multilocularis infection, which may contribute to regulating hepatic stellate cell activation and promoting fibrosis.