VAPB is a negative regulator of STING-mediated innate immune signaling.

Abstract

Stimulator of IFN genes (STING) is an endoplasmic reticulum (ER) signaling receptor involved in the type I interferon response to pathogen- or self-derived cytosolic double-stranded DNA. Excessive activation of STING is associated with many diseases, but the regulatory mechanism of STING activation remains to be further elucidated. Here, we identify VAPB as a negative regulator of STING-mediated innate immune response. VAPB deficiency increases the expression of type I interferons under resting conditions or upon stimulation. Mechanistically, VAPB associates and translocates with STING, thereby regulating STING translocation, oligomerization, and recruitment of TBK1. In vivo, deficiency of VAPB enhances the expression of type I interferons and prevents lethality following HSV-1 infection. Furthermore, VAPB P56S, a pathogenic mutation causing amyotrophic lateral sclerosis (ALS), can promote STING-mediated innate immune response under resting conditions, which might contribute to further understanding of the relationship between cGAS-STING pathway and ALS. Our study identifies VAPB as a critical regulating factor in cGAS-STING-mediated innate immune responses.