Mast cells are crucial for immune responses to pathogens, playing a key role in pathogen recognition and modulation of immune responses. They are located at host-environment interfaces and can rapidly release pro-inflammatory mediators. Mast cells can be activated by pathogens through various mechanisms, including direct recognition via pattern recognition receptors, Fc receptor binding, and exposure to pathogen-associated substances. They also respond to endogenous inflammatory factors and can modulate their phenotype during infection. Mast cells contribute to both innate and adaptive immunity by recruiting immune cells, promoting antigen presentation, and influencing cytokine production. They are essential for controlling infections, including those caused by parasites, bacteria, and viruses. Mast cells can also enhance vaccine efficacy by acting as adjuvants, promoting protective immunity. Despite their potential to cause harmful inflammation, mast cells are vital for host survival, as evidenced by their evolutionary conservation and their role in immune homeostasis. Understanding mast cell functions is important for developing strategies to harness their potential in immunotherapy and vaccine design.Mast cells are crucial for immune responses to pathogens, playing a key role in pathogen recognition and modulation of immune responses. They are located at host-environment interfaces and can rapidly release pro-inflammatory mediators. Mast cells can be activated by pathogens through various mechanisms, including direct recognition via pattern recognition receptors, Fc receptor binding, and exposure to pathogen-associated substances. They also respond to endogenous inflammatory factors and can modulate their phenotype during infection. Mast cells contribute to both innate and adaptive immunity by recruiting immune cells, promoting antigen presentation, and influencing cytokine production. They are essential for controlling infections, including those caused by parasites, bacteria, and viruses. Mast cells can also enhance vaccine efficacy by acting as adjuvants, promoting protective immunity. Despite their potential to cause harmful inflammation, mast cells are vital for host survival, as evidenced by their evolutionary conservation and their role in immune homeostasis. Understanding mast cell functions is important for developing strategies to harness their potential in immunotherapy and vaccine design.