Effects of MBL-associated serine protease-2 (MASP-2) on liquefaction and ulceration in rabbit skin model of tuberculosis

• The rabbit-skin model was establish by intradermal injection of viable BCG bacilli.
• The rAd-hMASP-2 accelerated the formation process of liquefaction and recovery.
• The rAd-hMASP-2 reduced the bacterial loads and increased serum levels of IL-2 and IFN-γ.

Tuberculosis is a chronic infectious disease, which caused by Mycobacterium tuberculosis. It typically affects the functions of the lung and causes high morbidity and mortality rates worldwide. The lectin pathway, one of the complement cascade systems, provides the primary line of defense against invading pathogens. However, what is the specific effection between tuberculosis and complement is unknown. Mannose-binding lectin (MBL), a recognition subunit, binds to arrays of carbohydrates on the surfaces of pathogens, which results in the activation of MBL-associated serine protease-2 to trigger a downstream reaction cascade of complement system. The effects of human MBL-associated serine protease-2 (hMASP-2) were assessed in a rabbit-skin model by intradermal injection of 5 × 106 viable BCG bacilli. The rAd-hMASP-2 accelerated the formation of liquefaction and healing of the granuloma lesions, reduced the bacteria loads of the skin nodules. The serum levels of IL-2 and IFN-γ were significantly increasing during the granuloma and liquefaction phases in the rAd-hMASP-2 group. This study suggests that hMASP-2 can induce a protective efficacy in BCG-infected rabbit skin models, which affects both the progress of lesions and the survival of the mycobacteria within them.