Multisystem Inflammation and Susceptibility to Viral infections in Human ZNFX1 Deficiency

Abstract

BACKGROUND The recognition of viral nucleic acids is one of the primary triggers for a type I interferon-mediated antiviral immune response. Inborn errors of type I interferon immunity can be associated with increased inflammation and/or increased susceptibility to viral infections, as a result of dysbalanced interferon production. NFX1-type zinc-finger-containing 1 (ZNFX1) is an interferon-stimulated double-strand RNA sensor that restricts the replication of RNA viruses in mice. ZNFX1's role in the human immune response is not known. OBJECTIVE We studied 15 patients from 8 families with an autosomal recessive immunodeficiency characterized by severe infections by both RNA and DNA viruses and virally triggered inflammatory episodes with hemophagocytic-lymphohistiocytosis-like disease, early-onset seizures, as well as renal and lung disease. METHODS Whole exome sequencing was performed on 13 patients from 8 families. We investigated the transcriptome, post-transcriptional regulation of interferon-stimulated genes (ISGs) and predisposition to viral infections in primary cells from patients and controls stimulated with synthetic double-stranded nucleic acids. RESULTS Deleterious homozygous and compound heterozygous ZNFX1 variants were identified in all 13 patients. Stimulation of patient-derived primary cells with synthetic double-stranded nucleic acids was associated with a deregulated pattern of expression of ISGs and alterations in the half-life of ISGs mRNA and was associated with poorer clearance of virus infections by monocytes. CONCLUSION ZNFX1 is an important regulator of the response to double-stranded nucleic acids stimuli following viral infections. ZNFX1 deficiency predisposes to severe viral infections and a multisystem inflammatory disease