Well-Controlled Mucosal Exudation of Undiluted Plasma Proteins Serves Innate and Adaptive Immunity

Area of Science:

• Immunology
• Respiratory Medicine
• Microcirculation Physiology

Background:

• The human respiratory mucosa has unique, superficial systemic microcirculations distinct from pulmonary circulation.
• Traditionally, plasma exudation into the mucosa during infection was thought to require epithelial injury.
• Recent in vivo studies challenge this view, suggesting a physiological process.

Purpose of the Study:

• To investigate the role of plasma exudation in respiratory mucosal immunity.
• To determine if plasma exudation is an injurious or protective mechanism during infection.
• To explore the potential of plasma exudation in preventing lower airway infections and severe respiratory disease.

Main Methods:

• The study synthesizes findings from well-controlled human in vivo observations.
• Analysis focuses on the early symptomatic phase of mucosal infections.
• Literature review and synthesis of existing data on plasma exudation and respiratory infections.

Main Results:

• Plasma exudation is a non-injurious physiological process involving microvascular-epithelial cooperation.
• It facilitates the transport of unfiltered plasma solutes to the mucosal surface without compromising the epithelial barrier.
• Exudation increases during infection resolution and aids in delivering antibodies to the upper airways.

Conclusions:

• Plasma exudation is a crucial component of human respiratory mucosal antimicrobial immunity.
• It has the potential to prevent the progression of infections to pneumonia and severe disease.
• Targeting plasma exudation could lead to new treatments for respiratory infections by enhancing innate and adaptive immunity.