The mucosal surface of the lung is the key interface between the external atmosphere and
the bloodstream. Normally, this well oxygenated tissue is maintained in state of sterility by a
number of innate immune processes. These include a physical and dynamic mucus barrier,
the production of microbiocidal peptides and the expression of specific pattern recognition
receptors on alveolar epithelial cells and resident macrophages and dendritic cells which
recognise microbial structures and initiate innate immune responses which promote the …