Mast Cells: Key Players in Host Defence Against Infection

Mast cells have long been recognised for their pivotal role in the development of allergic inflammation. However, their contributions extend far beyond this well-established function. Accumulating evidence supports that mast cells play essential roles in regulating both innate and adaptive immune responses by releasing a diverse array of potent immune mediators and cytokines. Importantly, mast cells are nowadays appreciated to possess the capacity to mount effective host defence responses against a variety of pathogens. One of the most notable features of mast cells is their abundance in mucosal tissues, which serve as primary entry points for many infectious agents, as well as common allergens. This strategic positioning enables mast cells to respond quickly to both harmful pathogens and allergens, making them key players in the body's first line of defence. In this review, we aim to summarise the current understanding of how mast cells contribute to the immune defence against infections. We will explore the mechanisms by which these cells respond to various pathogens and how their activation affects the overall immune response. Furthermore, we will discuss innovative strategies for harnessing mast cell activation to enhance vaccine efficacy. By exploiting the adjuvant properties of mast cell activators, we can potentially improve the quality of vaccination against infectious diseases. This exploration highlights the dual role of mast cells not only in allergic responses but also as vital components in the fight against infections, underscoring their importance in both immunology and therapeutic strategies.