•Ambient ASD (IT: 50 or 200 μg × 4 at weekly or 2 weekly intervals) exacerbates KP-induced pneumonia whilst accompanying in vitro studies suggest this is mediated by enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages. This evidence concerns the gene TLR2 and pneumonia.