Lipin-2 regulates the antiviral and anti-inflammatory responses to interferon

Interferons (IFN) are crucial antiviral and immunomodulatory cytokines that exert their function through the regulation of a myriad of genes, many of which are not yet characterized. Here, we reveal that lipin-2, a phosphatidic acid phosphatase whose mutations produce an autoinflammatory syndrome known as Majeed syndrome in humans, is regulated by IFN in a STAT-1-dependent manner. Lipin-2 inhibits viral replication both in vitro and in vivo. Moreover, lipin-2 also acts as a regulator of inflammation in a viral context by reducing the signaling through TLR3 and the generation of ROS and release of mtDNA that ultimately activate the NLRP3 inflammasome. Inhibitors of mtDNA release from mitochondria restrict IL-1 beta production in lipin-2-deficient animals in a model of viral infection. Finally, analyses of databases from COVID-19 patients show that LPIN2 expression levels negatively correlate with the severity of the disease. Overall, these results uncover novel regulatory mechanisms of the IFN response driven by lipin-2 and open new perspectives for the future management of patients with LPIN2 mutations. imageLipin-2 expression is controlled by interferons, reducing cytomegalovirus replication and inflammasome activation. Patients with decreased LPIN2 expression experience increased inflammatory responses during SARS-CoV-2 infection.Lipin-2 expression is regulated by interferons through STAT-1 activation.Lipin-2 controls cytomegalovirus replication.Lipin-2 restricts inflammasome activation and Il-1 beta production during viral encounters.Lipin-2 expression is reduced in symptomatic vs. asymptomatic COVID-19 patients. Lipin-2 expression is controlled by interferons, reducing cytomegalovirus replication and inflammasome activation. Patients with decreased LPIN2 expression experience increased inflammatory responses during SARS-CoV-2 infection.image