Cytokine responses during mucosal infections: role in disease pathogenesisand host defence

Mucosal pathogens use diverse and highly specific molecular mechanisms to a ctivate mucosal inflammation. It may even be argued that their virulence de pends on the inflammatory response that they induce. Some bacteria target e pithelial cells and trigger them to produce inflammatory mediators but othe rs cross the mucosa and activate macrophages or dendritic cells. Although s ystemic release of inflammatory mediators causes many symptoms and signs of infection, local chemokine production leads to the recruitment of inflamma tory cells and lymphocytes that participate directly in the clearance of ba cteria from mucosal sites. In this way, mucosal inflammation is a two-edged sword responsible for disease associated tissue destruction and crucial fo r the antimicrobial defence. Understanding of these pathways should create tools to enhance the defence and interfere with disease.