中文摘要：

目的应用M3受体蛋白多肽213-228（M3RP）免疫BALB／c小鼠。建立干燥综合征（SS）动物模型，以探讨M3RP在SS发病机制中的作用。方法应用M3RP100μg配合等体积佐剂，于0，14，35，51d进行尾根部皮下注射给药免疫4周龄的BALB／c小鼠，以颌下腺匀浆作为阳性对照，谷胱甘肽转移酶（GST）及磷酸盐缓冲液（PBS）作为阴性对照。观察小鼠饮水量的变化，酶联免疫吸附试验（ELISA）方法检测不同时间点小鼠血清中的M3RP抗体、α-胞衬蛋白（α-fodrin）抗体、抗SSA抗体、抗SSB抗体，类风湿因子（RF）及抗核抗体（ANA）等自身抗体，并测定血清中白细胞介素（IL）-2，IL-10和干扰素（IFN）-γ。应用苏木素-伊红（HE）染色和免疫组织化学方法检测小鼠的颌下腺及腮腺的病理改变及仅-胞衬蛋白的抗原分布。结果①M3RP免疫可诱导BALB／c小鼠血清自身抗体的产生。免疫前小鼠血清中的抗体均为阴性，而自初次免疫后第35天开始，在给予颌下腺匀浆及M3RP免疫的BALB／c小鼠中的M3RP抗体、α-胞衬蛋白抗体和ANA为阳性，而上述抗体在PBS和GST组为阴性。②M3RP免疫可导致BALB／c小鼠颌下腺淋巴细胞浸润和仅-胞衬蛋白的表达。自初次免疫后第56天开始，予颌下腺匀浆及M3RP免疫的BALB／c小鼠的腺体中出现少量淋巴细胞浸润，且随时间的延长，淋巴细胞浸润逐渐加重；而应用PBS和GST免疫的小鼠腺体无明显的病理改变。应用仅-胞衬蛋白多抗免疫组织化学的方法检测颌下腺匀浆及M3RP免疫的BALB／c小鼠的颌下腺组织有仅-胞衬蛋白表达，而PBS和GST组为阴性。③M3RP免疫可使BALB／c小鼠血清IFN-γ和IL-2水平升高。IFN-γ和IL-2在给予颌下腺匀浆及M3RP免疫后较对照组明显升高（P〈0.05），而IL-10在各实验组差异无统计学意义。结论M3RP可诱导BALB／c小鼠出现类似SS的表现，提示M3RP可能作为自身抗原参与了

英文摘要：

Objective To immunize BALB/c mice with type 3 muscafinic aeetylcholine receptor polypeptide （M3RP） and to evaluate the role of M3RP in SS. Methods Four-week-old BALB/c mice were immunized with M3R polypeptide 213-238 （M3RP） on days 0, 14, 35, 56, and were re-immuniged on days 65, 84, 105, and one mouse was killed every 2 to 3 weeks. The mice of the control group were immunized with submaxillary gland homogenate, GST, and PBS. The animals were analyzed for the presence of anti-SSA, anti-SSB, RF, ANA, anti-α-fodrin and anti-M3RP in sera by immunofluorescence or ELISA. The cytokines of IFN-γ IL-2 and IL-10 were measured with ELISA. Salivary glands were examined by H＆E staining and immunohistochemical analysis. Volume of water drinking by each groups were calculated. Results BALB/c mice immunized with M3RP and submaxillary gland homogenate developed an immune response directed against M3RP, α-fodfin and ANA, but no antibodies against SSA, SSB and RF were found. Furthermore, lymphocytic infiltrates in the salivary glands of immunized animals were observed 50 days after first immunization of M3RP and submaxillary gland homogenate. The serum IFN-α in mice of M3RP, submaxillary gland ho- mogenate, GST and PBS was （62±6）, （89±5）, （ 30±5 ） and （19±6） pg/ml respectively, and IL-2 was （ 12.6±1.6）, （19.8±0.4）, （3.9＋0.9）, and （4.9±1.1） pg/ml respectively （P〈0.05）. No difference was found in the level of serum IL-10 among the four group. Expression of α-fodrin was found only in submaxillary gland in M3RP and submaxillary gland homogenate groups of mice, but not in PBS and GST controls when studied by immunohistochemical analysis. Conclusion These results suggest that BALB/c mice immunized with M3RP are reminiscent of human SS, and M3RP as an autoantigen participates the development of SS.