Innate immune response to SARS-CoV-2 infection contributes to neuronal damage in human iPSC-derived peripheral neurons

Abstract

AbstractSevere acute respiratory coronavirus 2 (SARS-CoV-2) infection causes neurological disease in some patients suggesting that infection can affect both the peripheral and central nervous system (PNS and CNS, respectively). It is not clear whether the outcome of SARS-CoV-2 infection of PNS and CNS neurons is similar, and which are the key factors that cause neurological disease: SARS-CoV-2 infection or the subsequent immune response. Here, we addressed these questions by infecting human induced-pluripotent stem cell-derived CNS and PNS neurons with the β strain of SARS-CoV-2. Our results show that SARS-CoV-2 infects PNS neurons more efficiently than CNS neurons, despite lower expression levels of angiotensin converting enzyme 2. Infected PNS neurons produced interferon λ1, several interferon stimulated genes and proinflammatory cytokines. They also displayed neurodegenerative-like alterations, as indicated by increased levels of sterile alpha and Toll/interleukin receptor motif-containing protein 1, amyloid precursor protein and α-synuclein and lower levels of nicotinamide mononucleotide adenylyltransferase 2 and β-III-tubulin. Interestingly, blockade of the Janus kinase and signal transducer and activator of transcription pathway by Ruxolitinib did not increase SARS-CoV-2 infection, but reduced neurodegeneration, suggesting that an exacerbated neuronal innate immune response contributes to pathogenesis in the PNS.