Microbiota Composition and the Integration of Exogenous and Endogenous Signals in Reactive Nasal Inflammation

Abstract

The prevalence of reactive nasal inflammatory conditions, for example, allergic rhinitis and chronic rhinosinusitis, is steadily increasing in parallel with significant environmental changes worldwide. Allergens and as yet undefined environmental agents may trigger these conditions via the involvement of host intrinsic factors, including the innate and adaptive immune system, the nasal epithelium, and the nasal nervous system. The critical role of the nasal microbiota in coordinating these components has emerged in recent studies documenting a significant association between microbial composition and the onset and progression of allergic or nonallergic inflammation. It is now clear that the local microbiota is a major player in the development of the mucosa-associated lymphoid tissue and in the regulation of such adaptive responses as IgA production and the function of effector and regulatory T cells. Microbial components also play a major role in the regulation of epithelial barrier functions, including mucus production and the control of paracellular transport across tight junctions. Bacterial components, including lipopolysaccharide, have also been shown to induce or amplify neuroinflammatory responses by engaging specific nociceptors. Finally, bacterial products may promote tissue remodeling processes, including nasal polyp formation, by interacting with formyl peptide receptors and inducing the expression of angiogenic factors and matrix-degrading enzymes.

Dual and Triple Epithelial Coculture Model Systems with Donor-Derived Microbiota and THP-1 Macrophages To Mimic Host-Microbe Interactions in the Human Sinonasal Cavities

“…Another important parameter to consider for inclusion in upper respiratory tract model systems is the endogenous microbiota. Microbial populations in and on the sinonasal cavity and epithelium play an important role in immune priming and epithelial development (reviewed in Belkaid and Hand [13] and Salzano et al [14]) and have been proposed to play a modulating role in chronic airway diseases such as chronic rhinosinusitis (15,16). Jain et al (17) discovered functional and structural differences in the paranasal sinus epithelium between germfree and specific-pathogenfree mice, suggesting the importance of a healthy microbiota in normal epithelial development.…”

Diagnosis of Obstructive Sleep Apnea in Patients with Allergic and Non-Allergic Rhinitis

“…OSA disease is a common disorder characterized by the of repeated upper airway collapse during sleep, leading to oxygen desaturation and disrupted sleep. It involves about 1 billion people with prevalence exceeding 50% in some countries [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

Lacticaseibacillus casei AMBR2 modulates the epithelial barrier function and immune response in a donor-derived nasal microbiota manner

“…The human upper respiratory tract (URT), and more specifically the sinonasal cavities are in constant contact with the outside environment and its physical, chemical and infectious agents. The epithelium is however not alone in facing these potentially harmful external compounds; the human sinonasal cavities are colonised by a diverse microbial community that, in health, aids in maturation of the epithelium, immune priming, and can act as a colonisation barrier towards incoming infectious agents 1 – 7 . Loss of the balance in microbial composition or functionality (e.g.…”