Aggravating mechanisms from COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces immune-mediated diseases. The pathophysiology of COVID-19 uses the following three mechanisms: (1) inflammasome activation mechanism; (2) cGAS–STING signaling mechanism; and (3) SAMHD1 tetramerization mechanism, which leads to IFN-I production. Interactions between the host and virus govern induction, resulting in multiorgan impacts. The NLRP3 with cGAS–STING constitutes the primary immune response. The expression of SARS-CoV-2 ORF3a, NSP6, NSP7, and NSP8 blocks innate immune activation and facilitates virus replication by targeting the RIG-I/MDA5, TRIF, and cGAS–STING signaling. SAMHD1 has a target motif for CDK1 to protect virion assembly, threonine 592 to modulate a catalytically active tetramer, and antiviral IFN responses to block retroviral infection. Plastic and allosteric nucleic acid binding of SAMHD1 modulates the antiretroviral activity of SAMHD1. Therefore, inflammasome activation, cGAS–STING signaling, and SAMHD1 tetramerization explain acute kidney injury, hepatic, cardiac, neurological, and gastrointestinal injury of COVID-19. It might be necessary to effectively block the pathological courses of diverse diseases. Highlights: 1. DNA-driven immune response connects with NLRP3 and controls its inflammasome activity, which leads to IFN-I production via STING. The NLRP3 with cGAS-STING constitutes the primary immune response. 2. The expression of SARS-CoV-2 ORF3a, NSP6, NSP7, and NSP8 blocks innate immune activation and facilitates virus replication by targeting the RIG-I/MDA5, TRIF, and cGAS-STING signaling. 3. Plastic and allosteric nucleic acid binding of SAMHD1 reduces the magnitude of IFN and induction of virus-specific cytotoxic T cells. SAMHD1-deficient cells detect and activate IFN-I-mediated self ISG gene expression via cGAS–STING. 4. SAMHD1 autonomously controls viral infection through innate and adaptive immunity at the level of the infected cell. [ABSTRACT FROM AUTHOR]