Stress modulates intestinal secretory immunoglobulin A

Area of Science:

• Neuroimmunology
• Gastroenterology
• Stress Physiology

Background:

• Stress responses involve the central nervous system, activating hormonal and neural axes that modulate the gut immune system.
• Psychological stress impacts intestinal immunity, primarily studied using rodent models, leading to variable changes in secretory IgA (SIgA) levels.
• Secretory IgA (SIgA), crucial for gut defense, is formed by immunoglobulin A (IgA) and a secretory component (SC) derived from the polymeric immunoglobulin receptor (pIgR).

Purpose of the Study:

• To review the impact of stress on the generation of SIgA, pIgR, and other immune components within the intestinal environment.
• To analyze the molecular and biochemical mechanisms underlying stress-induced alterations in intestinal immunity, moving beyond systemic focus.
• To provide insights for developing therapies that protect against pathogens and mitigate stress-related epithelial damage.

Main Methods:

• Review of existing literature, primarily focusing on rodent models of restraint/immobilization stress.
• Analysis of studies investigating the modulation of SIgA, pIgR, and other humoral and cellular immune factors in response to stress.
• Examination of the role of the hypothalamus-pituitary-adrenal axis, sympathetic axis, and gut-brain axis in mediating stress effects on intestinal immunity.

Main Results:

• Stress exposure, particularly immobilization, can lead to either an increase or decrease in SIgA levels, contingent on stress intensity and duration.
• Reduced SIgA levels are associated with compromised intestinal integrity, facilitating pathogen adhesion and increasing intestinal permeability.
• The review highlights that most research has focused on systemic immunity, necessitating a greater focus on stress effects on the gut-specific immune system.

Conclusions:

• Stress-induced down-modulation of SIgA poses significant risks to intestinal function and defense mechanisms.
• Understanding the intricate mechanisms of stress on intestinal immunity is essential for developing novel therapeutic strategies.
• Targeting these stress-mediated pathways could offer new avenues for preventing gut infections and managing inflammatory conditions.