Interactions of the immune and sensory nervous systems in atopy

Abstract

A striking feature underlying all atopic disorders, such as asthma, atopic dermatitis, and food allergy, is the presence of pathologic sensory responses, reflexes, and behaviors. These symptoms, exemplified by chronic airway irritation and cough, chronic itch and scratching, as well as gastrointestinal discomfort and dysfunction, are often cited as the most debilitating aspects of atopic disorders. Emerging studies have highlighted how the immune system shapes the scope and intensity of sensory responses by directly modulating the sensory nervous system. Additionally, factors produced by neurons have demonstrated novel functions in propagating atopic inflammation at barrier surfaces. In this review, we highlight new studies that have changed our understanding of atopy through advances in characterizing the reciprocal interactions between the immune and sensory nervous systems.

The Neuropeptide Y Y2 Receptor Is Coexpressed with Nppb in Primary Afferent Neurons and Y2 Activation Reduces Histaminergic and IL-31-Induced Itch

“…Thus, although the NPY/Y 2 system can reduce scratching induced by IL-31, an interleukin involved in atopic dermatitis, the NPY/Y 2 system did not have a clear effect in reducing scratch behavior in a translational model of atopy. Atopic dermatitis is also associated with IL-4, IL-5, and IL-13 (Oetjen and Kim, 2018), which may be reflected in the different treatment outcomes.…”

Neuro-immune crosstalk and allergic inflammation

“…SP, substance P. stance P-positive nerve fibers, with increased mast cells expressing substance P's receptor (NK-1R) compared with nonlesional skin. This finding implies that innervation and neuropeptides play a role in the pathogenesis of AD (30)(31)(32). Sensory nervederived substance P induces mast cell degranulation and release of histamine, TNF-α, leukotriene B 4 , and vascular endothelial growth factor (VEGF) (ref.…”

SnapshotDx Quiz: September 2020

“…Type 2 cytokines (including IL-4 and IL-13) activate type 2 cellular immune responses that are responsible for the inflammation and itch associated with AD (Oetjen and Kim, 2018;Trier and Kim, 2018). Dupilumab, an antieIL-4 mAb, is a relatively new therapy for AD, which has been effective in reducing itch symptoms (Beck et al, 2014;Guttman-Yassky et al, 2019;Simpson et al, 2016;Thaçi et al, 2016).…”