[目的]研究补体调节蛋白CD46在聚肌胞苷酸(poly I∶C)加重三氯乙烯(TCE)致敏小鼠免疫性肝损伤中的表达和转录水平.[方法] 6～8周的雌性BALB/c小鼠36只,随机分为空白对照组(4只),溶剂对照组(4只),TCE组(15只),TCE+poly I∶C组(13只),适应性喂养1周,于第1、4、7、10天作致敏处理,第17、19天作激发处理,TCE+poly I∶C组于末次激发前3h腹腔注射100 μL含50 μg poly I∶C的液体.末次激发24h后进行皮肤评分,48h后取小鼠血清及肝脏,试剂盒检测丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST),HE染色法观察小鼠肝脏病理,免疫组化法检测小鼠肝脏CD46和C3片段的表达,RT-PCR法检测肝脏CD46 mRNA表达水平.[结果]空白对照组与溶剂对照组小鼠背部皮肤无水肿与红斑,TCE处理组致敏率33.3％(5/15),TCE+polyI∶C处理组致敏率38.5％(5/13),差异无统计学意义.与溶剂对照组比较,TCE致敏组和TCE+polyI∶C致敏组肝脏系数升高,差异有统计学意义(P＜0.01).血清ALT和AST值在空白对照组、溶剂对照组以及未致敏组之间的差异均无统计学意义;与溶剂对照组相比,TCE致敏组和TCE+poly I∶C致敏组ALT和AST值升高,TCE+poly I∶C致敏组ALT和AST值相对TCE致敏组升高,差异有统计学意义(P＜0.01).肝脏病理检测发现TCE致敏组小鼠细胞形态异常,部分区域出现细胞水肿,而TCE+poly I∶C致敏小鼠肝脏出现大面积的细胞空泡样变性,肝细胞浆疏松且伊红染色变浅.小鼠肝脏免疫组化显示TCE致敏组C3片段少量沉积,TCE+poly I∶C组C3片段大量沉积,空白对照组、溶剂对照组与未致敏组则未发现.小鼠肝脏免疫组化显示CD46在肝脏细胞膜部位表达,空白对照组、溶剂对照组以及未致敏组高表达,TCE致敏组表达减少,而TCE+poly I∶C致敏组CD46表达极少.肝脏CD46转录水平在空白对照组、溶剂对照组以及未致敏组之间差异均无统计学意义;与溶剂对照组相比,TCE致敏组和TCE+poly I∶C致敏组CD46转录水平下降,TCE+poly I∶C致敏组CD46的转录水平较TCE致敏组下降,差异有统计学意义(P＜0.01).[结论] CD46可能在poly I∶C加重TCE致敏小鼠免疫性肝损伤中发挥重要作用.“,”[Objective] To study the expression and transcription of complement regulatory protein CD46 in immune liver injury of trichlorethylene (TCE) sensitized mice exacerbated by poly I∶ C.[Methods] Thirty-six female BALB/c mice (6-8 weeks old) were randomly divided into blank control group (n=4),solvent control group (n=4),TCE treatment group (n=15),and TCE+poly I ∶ C treatment group (n=13).Sensitization treatment was administered on day 1,4,7,and 10 after adaptive feeding for one week,and challenge on day 17 and 19.The mice in the TCE+poly I ∶ C treatment group were given intraperitoneal injection of 50 μg poly I∶ C at 3 h before last challenge treatment.Mice skin reactions were observed and scored at 24 h after the last challenge.ALT and AST were detected by commercial kit from serum and liver samples at 48 h after challenge.Histological damage of liver was observed by HE staining.Expressions of CD46 and C3 fragment were observed by immunohistochemistry.mRNA expressions of CD46 were detected by RT-PCR.[Results] There was no skin erythema or edema in the blank control group and the solvent control group.The sensitization rate was 33.3％ (5/15) in the TCE treatment group and 38.5％ (5/13) in the TCE+poly I∶ C treatment group,with no statistical differences.The liver/body coefficients in the TCE sensitized group and the TCE+pply I ∶ C sensitized group were significantly higher than that in the solvent control group (P＜ 0.01).No difference in the serum levels of ALT and AST was observed among the blank control group,the solvent control group,and the non-sensitized group.Compared with the solvent control group,the serum levels of ALT and AST in the TCE sensitized group and the TCE+poly I∶C sensitized group were increased (P ＜ 0.01).Compared with the TCE sensitized group,the serum levels of ALT and AST in the TCE+poly I∶C sensitized group were higher (P＜0.01).Pathology examination of liver showed abnormal cell morphology and cell edema in the TCE sensitized group,and a large area of vacuolar degeneration of cells was observed in the TCE+poly I ∶ C sensitized group,leading to liver cell cytoplasm loose and eosin staining lighter.Immunohistochemistry results showed little C3 fragment in TCE sensitized group,but largely deposited in the TCE+poly I ∶ C group,and none in the blank control group,the solvent control group,and the non-sensitized group.The liver immunohistochemical assay results showed high expression of CD46 in liver cell surface in the blank control group,the solvent control group,and the non-sensitized group,reduced expression in the TCE sensitized group,and minimal in the TCE+poly I∶C sensitized group.There was no difference in transcriptions of CD46 among the blank control group,the solvent control group,and the non-sensitized group.However,compared with the solvent control group,the transcription was decreased in the TCE sensitized group and the TCE+poly I ∶ C sensitized group.Compared with the TCE sensitized group,the transcriptions of CD46 in the TCE+poly I ∶ C sensitized group were decreased (P ＜ 0.01).[Conclusion] CD46 may play an important role in poly I∶ C exacerbated immune liver injury in TCE sensitized mice.