Alveolar macrophages (AM), which are enhanced by GM-SCF, are an essential piece of the innate immune response and are known to contribute to host defense against flu infections in animal models.

At any time the macrophage system might be injured by viral infection or air pollutant exposure.

Conclusion Macrophages are the main antigen presenting cells in the lung tissue of cynomolgus macaque infected with avian influenza virus.