Immune cells are essential components of tissue defense. Cells like macrophages, dendritic cells, and lymphocytes patrol tissues and respond to invading pathogens. Macrophages and dendritic cells function as antigen-presenting cells, initiating adaptive immune responses by interacting with lymphocytes. In tissues like the gastrointestinal tract, the presence of gut-associated lymphoid tissue (GALT) provides a robust defense mechanism. Any deficiencies in the recruitment or function of these immune cells can significantly impair the ability to fend off infections.
