Final answer:
Specialized M cells and dendritic cells in the Peyer's patches of the small intestine play a key role in the early immune response to ingested pathogens, with phagocytic cells like macrophages also contributing to engulfing invaders.
Step-by-step explanation:
The cells that participate in the early immune response to ingested pathogens in food are specialized cells called microfold or M cells and dendritic cells. M cells are found in the mucosal tissues such as the Peyer's patches in the small intestine. They function by taking up particulate antigens from the intestinal lumen, which allows the body to sample potential pathogens. Following this, dendritic cells take the sampled antigen to the regional lymph nodes, where an early induced immune response is mounted, involving other immune cells such as lymphocytes and macrophages.
Phagocytic cells like macrophages also play a key role in the innate immune response by engulfing invading pathogens. When the innate immune barriers such as skin and mucus are breached, an inflammation response is triggered, causing various immune cells, including natural killer (NK) cells and white blood cells, to become active against the pathogens.