Allergen tolerance is an active physiological process opposite to
adaptive immune response. Nowadays, understanding of allergen tolerance
mechanisms is extremely critical in the course of allergen-specific
immunotherapy (ASIT) in atopic diseases [Akdis M, Akdis CA, 2014].
The induction of tolerance involves the multiple regulatory networks of
cells and molecules. There are natural T regulatory (nTreg) cells,
allergen-specific Treg cells, tolerogenic dendritic (tDC) cells and
IL10, IL35, TGF, neurotransmitters, etc. In this review, immune
tolerance is initially considered at a glance [Klimov VV, 2019].
Then the review focuses on mechanisms of physiological induction of
allergen tolerance throughout the body, and pathogenesis of allergen
tolerance breakdown with particular emphasis on both systemic and
autonomous starting-off, taking into account two diverse atopic entities
(endotypes), conventional allergic rhinitis and local allergic rhinitis