Figure 1.

Role of SLPI and elafin in innate immunity. A representation of the alveolar space (delineated by the epithelium) and some of the molecules believed to be involved in innate immunity is shown. SLPI and elafin are elastase inhibitors that might be ideally placed to fight infection together with other molecules of the collectin family [such as the surfactant proteins A (SP-A)] and defensins (indicated by 1). In addition, SLPI and elafin have a role in modulating inflammation by inhibiting the neutrophil elastase (HNE, indicated by 2) and its potential deleterious effects on epithelial cells (indicated by 3) or by interfering with the agonistic effects of LPS on alveolar macrophages (indicated by 4, dotted line).