The role of innate immunity in the pathogenesis of chronic rhinosinusitis

Abstract

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory condition with a multifactorial basis. Infectious triggers of CRS have been proposed, but demonstration remains elusive. Evolving research suggests that abnormal host mucosal immune responses, rather than specific pathogens themselves, may underlie the chronic inflammatory state. Despite constant contact with airborne particulates and microorganisms, the sinonasal epithelium maintains mucosal homeostasis through innate and adaptive immune mechanisms that eliminate potential threats. Innate immunity encompasses a broad collection of constitutive and inducible processes that can be nonspecific or pathogen directed. Some innate immune pathways are closely intertwined with tissue growth and repair. The persistent inflammation observed in CRS may result from a pathologic imbalance in innate immune interactions between the host and the environment. Impairment of critical innate immune protection renders the sinonasal mucosal surface susceptible to colonization and potential injury, stimulating the prominent adaptive immune response that characterizes CRS.

Natural Killer Cell Deficits Aggravate Allergic Rhinosinusitis in a Murine Model

“…Because the pathogenesis of CRS remains incompletely understood, imbalances in the innate immune system have been proposed as a mechanism to explain these persistent sinonasal inflammations [1]. Eosinophilic CRS can be particularly unresponsive to medical and surgical treatment [9,17,18,19].…”

“…Innate immunity provides multiple first lines of defense against airborne microorganisms and particulates, and adaptive immunity develops on the foundation of innate immunity [1,2]. The innate and adaptive immune systems cooperatively identify and eliminate infectious agents from the sinonasal cavity [3].…”

“…The innate and adaptive immune systems cooperatively identify and eliminate infectious agents from the sinonasal cavity [3]. Defects in the innate immune system regulation of inflammation and restoration of homeostasis have recently been proposed as important pathogenic factors of persistent sinonasal inflammation of chronic rhinosinusitis (CRS) [1,4,5]. Although the pathognomonic features of CRS are mainly attributed to sustained inflammation associated with an activated local adaptive immune system [1], CRS-induced inflammation has multifactorial causes that are related to overlapping host reaction and environmental triggers [3].…”

“…Defects in the innate immune system regulation of inflammation and restoration of homeostasis have recently been proposed as important pathogenic factors of persistent sinonasal inflammation of chronic rhinosinusitis (CRS) [1,4,5]. Although the pathognomonic features of CRS are mainly attributed to sustained inflammation associated with an activated local adaptive immune system [1], CRS-induced inflammation has multifactorial causes that are related to overlapping host reaction and environmental triggers [3]. The complex interaction between the environment and the mucosal immune system is magnified by factors that drive persistent sinonasal inflammation [1,3].…”

“…Although the pathognomonic features of CRS are mainly attributed to sustained inflammation associated with an activated local adaptive immune system [1], CRS-induced inflammation has multifactorial causes that are related to overlapping host reaction and environmental triggers [3]. The complex interaction between the environment and the mucosal immune system is magnified by factors that drive persistent sinonasal inflammation [1,3]. …”