Final answer:
The immune system is typically tolerant to 'self-antigens,' a term used to describe the body's own tissues and cells. Immune tolerance is mediated by antigen-presenting cells and regulatory T cells to prevent harmful immune responses against these self-antigens while maintaining readiness against actual pathogens.
Step-by-step explanation:
The general name for the antigen to which the immune system is normally tolerant is a self-antigen. Immune tolerance is the process by which the immune system is trained to recognize and not mount a defensive response against these self-antigens or harmless foreign substances, such as food proteins.
This is essential to maintaining homeostasis and preventing an immune reaction that could be harmful to the host body. Specialized antigen-presenting cells (APCs) and regulatory T cells (Treg cells) play critical roles in this process.
APCs in the liver, lymph nodes, small intestine, and lung present non-threatening antigens to Treg cells which suppress local inflammation and inhibit the secretion of stimulatory immune factors. This helps to prevent immunologic activation in undesired areas and allows the immune system to focus on actual pathogens, preserving the integrity of host tissue.