【摘要】 【目的】通过小鼠侧脑室注射卡介苗(BCG)致中枢神经系统结核分枝杆菌(MTB)感染,检测小鼠血清中是否有视神经脊髓炎(NMO)-IgG/水通道蛋白4(AQP4)-Ab的表达。【方法】雌性C57BL/6J小鼠40只,6～8周,随机分为4组:5×106CFU BCG组、1×106CFU BCG组、0.01 mol/L PBS组、正常组。右侧侧脑室注射,注射后1周脑室注射追加1次。小鼠BCG注射后第7、14、21、28天,分别取血并检测血清中NMO-IgG/AQP4-Ab。注射后第28天处死小鼠行抗酸杆菌培养,并对脑和脊髓进行HE、抗酸、LFB髓鞘染色,免疫组化检测病灶处AQP4、GFAP的表达及C5b9沉积情况。【结果】脑室注射后,BCG组小鼠行为活动降低,出现肢体瘫痪,甚至死亡,其中5×106CFU BCG组表现严重,死亡率高。注射卡介苗21 d时小鼠血清检测发现5×106CFU BCG组中2只小鼠血清NMO-IgG/AQP4-Ab阳性,1×106CFU BCG组中4只小鼠血清中抗体阳性。第28天时5×106CFU BCG组的两只血清阳性的小鼠死亡,1×106CFU BCG组中原抗体阳性的小鼠血清中抗体仍为阳性。病理检测显示脑和脊髓出现炎性细胞浸润,病灶处抗酸染色阳性,出现脱髓鞘改变。组织培养3周后可见MTB生长,免疫组化显示病灶区域AQP4、GFAP表达降低,部分炎性细胞及血管周围出现补体C5b9沉积。【结论】中枢神经系统MTB直接感染可诱导产生NMO-IgG/AQP4-Ab。更多还原

【Abstract】 【Objective】To investigate whether cerebral mycobacterium tuberculosis infection can induce NMO-IgG/AQP4-Ab expression.【Methods】Forty female C57BL/6J mice(6-8 weeks old) were randomly divided into 5 × 106 CFU BCG group,1 × 106 CFU BCG group,0.01 mol/L PBS control groups and normal control group.Different dose of BCG in 10 μL of PBS or PBS alone was injected into the lateral ventricle of the right frontal lobe of mice using micropipette.Repeated injections were done with the same injecting 1 week later.We collected the sera of the mice to detect NMO-IgG/AQP4 antibody by IIF and CBA at day 7,14,21,and 28.Clinical parameters and ethology were monitored after injection.The pathologic changes of the CNS were studied by HE staining histopathology,Ziehl-Neelsen stain for acid-fast bacilli,LFB for demyelination.AQP4,GFAP,and C5b9 expression were determined using immunohistochemistry.【Results】BCG intracerebral injections significantly decreased neurofunctional scores in mice when compared with control group,even leading paralysis or death.NMO-IgG/AQP4-Ab was detected two positive in the 5 × 106 CFU BCG group and 4 positive in the 1 × 106 CFU BCG at 21-day time point.None is positive in the PBS and normal group.At the 28 days,in the 5 × 106 CFU BCG group the two mice with NMO-IgG positive died,while in the 1 × 106 CFU group,the mice with NMO-IgG positive still was positive.Pathologically,BCG infection leads to accumulation of inflammatory cell in the CNS and induces persistent inflammatory lesions.Demyelination and positive Ziehl-Neelsen(ZN) staining were observed near the lesions.The immunohistochemical findings include decrease of aquaporin-4 expression,decrease of GFAP expression in the lesions and perivascular deposition of C5b9.【Conclusion】The MTB infection in the central nervous system can induce the expression of NMO-IgG/AQP4-Ab.更多还原