Bioaerosols and innate immune responses in airway diseases

Abstract

Purpose of review: We review the role of bioaerosols in the pathogenesis of inflammatory airway disease. The focus is on recent discoveries in innate immune responses induced by common components of bioaerosols.

Recent findings: Common components of bioaerosols include endotoxin, peptidoglycan and beta-glucan; all of which have been associated with inflammatory airway disease. Endotoxin signaling through toll-like receptor 4 is well characterized and updated. Peptidoglycan is now known to signal through three types of molecules: toll-like receptor 2; peptidoglycan recognition proteins; and nucleotide-binding oligomerization domain molecules. Beta-glucan, a common fungal cell wall component, signals through the newly discovered receptor, dectin-1. Emerging data indicate that genetic polymorphisms influence the response to bioaerosols.

Summary: Activation of the innate immune system by bioaerosols is becoming better understood. This knowledge provides an opportunity to better prevent and treat airway diseases that result from environmental exposure.