Research progress of correlation between pulmonary surfactant associated protein A, D and Mycobacterium tuberculosis infection

Abstract

Pulmonary surfactants are synthesized and secreted by alveolar epithelial cells and bronchial epithelial cells,including SPA,SP-B,SP-C,SP-D,etc.. They play an important role in immune regulation and inflammatory response of the lung, among of which, SP-A and SP-D are the most important. Pulmonary tuberculosis is a state that allergic reaction and immune reaction exist at the same time induced by Mycobacterium tuberculosis. Mycobacterium tuberculosis goes through the respiratory tract before invading alveolous,and is phagocytized by alveolar macrophages. Pulmonary surfactants play an important intermediary role between Mycobacterium tuberculosis and alveolar macrophages. SP-A can recognize the receptors or other sugar moleculars on the cell wall of Mycobacterium tuberculosis. SP-D can bind with lipoarabinomannan on the surface of Mycobacterium tuberculosis. They are regulated and limited by certain factors in mediating the adhesion of Mycobacterium tuberculosis and alveolar macrophages, finally decide the degree of adhesion between Mycobacterium tuberculosis and alveolar macrophages, and determine the proliferation or degradation of Mycobacterium tuberculosis after entering into the body. Key words: Mycobacterium tuberculosis; Alveolar macrophage; SP-A; SP-D