The phagocyte oxidative burst, mediated by Nox2 NADPH oxidase-derived reactive oxygen species, confers host defense against a broad spectrum of bacterial and fungal pathogens. Loss-of-function mutations that impair function of the Nox2 complex result in a life-threatening immunodeficiency, and genetic variants of Nox2 subunits have been implicated in pathogenesis of inflammatory bowel disease (IBD). Thus, alterations in the oxidative burst can profoundly impact host defense, yet little is known about regulatory mechanisms that fine-tune this response. Here we report the discovery of regulatory nodes controlling oxidative burst by functional screening of genes within loci linked to human inflammatory disease. Implementing a multi-omics approach, we define transcriptional, metabolic and ubiquitin-cycling nodes controlled by Rbpj, Pfkl and Rnf145, respectively. Furthermore, we implicate Rnf145 in proteostasis of the Nox2 complex by endoplasmic reticulum-associated degradation. Consequently, ablation of Rnf145 in murine macrophages enhances bacterial clearance, and rescues the oxidative burst defects associated with Ncf4 haploinsufficiency.
Bibliographical noteFunding Information:
We are grateful to Dr Agnès Gardet for her help in designing, optimizing and completing the screen, and Bihua Li for technical assistance. We thank Drs Jeffrey Silva and Matthew Stokes at Cell Signaling Technology for expert assistance with proteomics. In addition, we thank Drs Moran Yassour, Isabel Latorre and Natalia Nedelsky for critical comments and advice. R.J.X. was supported by funding from The Leona M. and Harry B. Helmsley Charitable Trust, the Crohn’s and Colitis Foundation of America Genetics Initiative and the National Institutes of Health grant DK043351.