Independent and inter-dependent immunoregulatory effects of NCF1 and NOS2 in experimental autoimmune encephalomyelitis

Jianghong Zhong,Rikard Holmdahl,Anthony C Y Yau

doi:10.1186/s12974-020-01789-2

Abstract

BackgroundIncreasing evidence has suggested that a single nucleotide polymorphism in the Ncf1 gene is associated with experimental autoimmune encephalomyelitis (EAE). However, the mechanisms of NCF1-induced immunoregulatory effects remain poorly understood. In this study, we focus on NCF1 deficiency-mediated effects on EAE in NOS2 dependent and independent ways.MethodsTo determine the effects of NCF1 and NOS2 during EAE development, we have established recombinant mouse strains deficient at NCF1 and/or NOS2 in a crossbreeding system. Different strains allow us to examine the entire course of the disease in the Nos2-null mice bearing a Ncf1 gene that encodes a mutated NCF1, deficient in triggering oxidative burst, after immunization with recombinant myelin oligodendrocyte glycoprotein (MOG)79-96 peptides. The peptide-induced innate and adaptive immune responses were analyzed by flow cytometry.ResultsNCF1-deficient mice developed a reduced susceptibility to EAE, whereas NCF1-NOS2 double-deficient mice developed an enhanced EAE, as compared with NOS2-deficient mice. Flow cytometry analyses show that double deficiencies resulted in an increase of neutrophils in the spleen, accompanied with higher release of interleukin-1β in neutrophils prior to EAE onset. The additional deficiency in NCF1 had no added effect on either interleukin-17 or interferon-γ secretion of T cells during the priming phase.ConclusionsThese studies show that NCF1 and NOS2 interact to regulate peptide-induced EAE.

Highlights

Increasing evidence has suggested that a single nucleotide polymorphism in the Ncf1 gene is associated with experimental autoimmune encephalomyelitis (EAE)
It has been shown that the H-2b mice that were deficient in neutrophil cytosol factor 1 (NCF1) and CYBB subunits of the NOX2 complex were partially protected from EAE when induced by the rat MOG1-125 protein or mouse MOG35-55 peptide [14, 15]
Based on oxidative burst products generated by the NCF1-NOX2 complex, it is difficult to determine the exact level of peroxynitrite among superoxide, nitric oxide (NO), peroxynitrite, and hydrogen peroxide

Summary

Introduction

Increasing evidence has suggested that a single nucleotide polymorphism in the Ncf gene is associated with experimental autoimmune encephalomyelitis (EAE). In the rat model of EAE, the Ncf polymorphism leading to a reduction but not deficiency in superoxide production enhanced the disease severity [11, 12]. A mutation in Ncf gene, leading to a nearly deficient superoxide production by the NOX2 complex, resulted in an enhanced EAE, in a model that was induced by recombinant rat myelin oligodendrocyte glycoprotein (MOG)125 protein; in contrast, immunization with a mouse MOG79-96 peptide led to reduced EAE [5]. It has been shown that the H-2b mice that were deficient in NCF1 and CYBB subunits of the NOX2 complex were partially protected from EAE when induced by the rat MOG1-125 protein or mouse MOG35-55 peptide [14, 15]

Methods

Results

Conclusion