No abstract

Patients infected with SARS-CoV-2 variants lacking open reading frame 8 (ORF8) have been associated with milder infection and disease outcome, but the molecular mechanism behind how this viral accessory protein mediates disease pathogenesis is not yet known. In our study, we revealed that secreted ORF8 protein mimics host IL-17 to activate IL-17 receptors A and C (IL-17RA/C) and induces a significantly stronger inflammatory response than host IL-17A, providing molecular insights into the role of ORF8 in COVID-19 pathogenesis and serving as a potential therapeutic target.

While pregnancy increases the risk for severe COVID19, the clinical and immunological implications of COVID19 on maternal-fetal health remain unknown. Here, we present the clinical and immunological landscapes of 93 COVID19 mothers and 45 of their SARS-CoV-2-exposed infants through comprehensive serum proteomics profiling for >1400 cytokines of their peripheral and cord blood specimens. Prenatal SARS-CoV-2 infection triggers NF-κB-dependent proinflammatory immune activation. Pregnant women with severe COVID19 show increased inflammation and unique IFNλ antiviral signaling, with elevated levels of IFNL1 and IFNLR1. Furthermore, SARS-CoV-2 infection re-shapes maternal immunity at delivery altering the expression of pregnancy complication-associated cytokines, inducing MMP7, MDK, ESM1, and reducing BGN and CD209. Finally, COVID19-exposed infants exhibit induction of T cell-associated cytokines (IL33, NFATC3 and CCL21), while some undergo IL-1β/IL-18/CASP1 axis-driven neonatal respiratory distress despite birth at term. Our findings demonstrate COVID19-induced immune rewiring in both mothers and neonates, warranting long-term clinical follow-up to mitigate potential health risks.