Defining the molecular role of gp91phox in the immune manifestation of acute allergic asthma using a preclinical murine model

Ena Ray Banerjee,William R Henderson

doi:10.1186/1476-7961-10-2

Ena Ray Banerjee, William R Henderson

Open Access

https://doi.org/10.1186/1476-7961-10-2

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Abstract

ObjectiveThe phenomena manifested during inflammation require interplay between circulating effector cells, local resident cells, soluble mediators and genetic host factors to establish, develop and maintain itself. Of the molecues involed in the initiation and perpetuation of acute allergic inflammation in asthma, the involvement of effector cells in redox reactions for producing O2- (superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them.Materials and Methods and TreatmentTo clarify the role of gp91phox subunit of NADPH oxidase in the development and progression of an acute allergic asthma phenotype, we induced allergen dependent inflammation in a gp91phox-/- single knockout and a gp91phox-/-MMP-12-/- double knockout mouse models.ResultsIn the knockout mice, both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma. While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway (comparing data from gp91phox-/- and gp91phox-/-MMP-12-/- mice).

Highlights

Asthma is a complex syndrome with well described pathology
OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and bronchoalveolar lavage fluid (BALf), accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma
While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway

Summary

Results

Cellularity in bone marrow, blood, lungs and airways Cellularity was increased in post-OVA mice compared to saline treated mice. Recruitment index (Table 2) was increased in B cells, monocytes, PMNs, Eosinophils and basophils in both KO mice post-OVA compared to post-OVA WT. Inflammation in the lungs Histopathology showed a marked increase in peribronchiolar and perivascular infiltration of inflammatory cells post-OVA in both KO mice compared to control (Figure 5A-C).

Introduction

Materials and methods

Discussion

14. Henderson WR

17. Ena Ray Banerjee