IMMUNOLOGY

Detailed explanation-1: -In general, a patient that presents with a type I hypersensitivity usually develops a reaction within one hour after exposure to an antigen. The signs and symptoms exhibited in this type of reaction involve vasoactive mediators that are released by IgE bound mast cells and basophils.

Detailed explanation-2: -Mast cells are now thought to exert critical proinflammatory functions, as well as potential immunoregulatory roles, in various immune disorders through the release of mediators such as histamine, leukotrienes, cytokines chemokines, and neutral proteases (chymase and tryptase).

Detailed explanation-3: -Innate and Adaptive Immunity Most commonly the receptors on the mast cells are TLRs and receptors for complement. Once the antigen binds to the receptors on the mast cell, it causes the release of inflammatory mediators, which helps to eliminate the pathogen that activated it.