Mast cells for the control of mucosal immunity

Mast cells (MCs) are gaining recognition as key initiators and coordinators of host inflammatory and immune responses to various microbial pathogens. Their presence in mucosal tissues and skin make them one of the first immune cells to make contact with incoming pathogens. MCs can be readily activated at infection sites and release their collection of prestored and de novo synthesized mediators to initiate immune responses. Additionally, since MCs are in close proximity to blood vessels, they help to augment immune cell mobilization from the circulation to the infection site. However, not all MC reactions are beneficial, and if MCs become overactivated, as is observed with chronic or systemic infections, pathogenic sequelae ensue. In view of the powerful immunomodulatory role of MCs, there is growing interest in targeting these cells to either boost immunity or diminish harmful inflammatory outcomes of severe or chronic infection.