Diverse Functions of Pulmonary Collectins in Host Defense of the Lung

Figure 2

Roles of pulmonary collectins in host defense against L. pneumophila. During infection, L. pneumophila secretes various effector molecules via type IV secretion system to manipulate the host cell immune responses. This results in pore-forming on host cell membrane. The secreted effector molecules enable L. pneumophila to bypass phagosomes-lysosome fusion and survive in characteristic vacuoles consisted of ER-derived membrane. Pulmonary collectins protect macrophage membrane against pore-forming activity of L. pneumophila. The collectins also attenuate intracellular growth of L. pneumophila in part by facilitating phagosomes-lysosome fusion.