Effects of hMASP-2 on the formation of BCG infection-induced granuloma in the lungs of BALB/c mice

Tuberculosis, caused by Mycobacterium tuberculosis, affects the functions of the lung and causes high morbidity and mortality rates worldwide. MASP-2 is an executioner enzyme, which plays an essential role in the activation of lectin pathway. In our previous studies, the MASP-2 played a dual role in promoting the progress of lesions in BCG-infected rabbit skin models. However, the really effects of MASP-2 on tuberculosis are unknown. The aim of this study was to investigate the effects of MASP-2 in granuloma formation with BCG-infected mice. Compared to the control group, rAd-hMASP-2 treated group showed increasing in survival rate of BCG-infected mice (P = 0.042), and decreasing of bacteria loads (P = 0.005) in the lung tissue. MASP-2 displayed a protective efficacy in BCG-infected mice, which promoted the activation and recruitment of macrophages and lymphocytes to the granuloma. Moreover, the data obtained from the ELISA and RT-PCR demonstrated that mRNA expression for IL-6, CCL12, CCL2 and cytokines of IFN-γ, TNF-α in lung were significantly elevated by treatment of rAd-hMASP-2. Those findings provided an evidence that MASP-2 may be as a newly immunomodulatory in targeting granuloma formation, which displayed a potential protective role in control of tuberculosis.