【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.