Laboratory of Innate Immunity and Cell Death Publication


Synergism of TNF-α and IFN-γ Triggers Inflammatory Cell Death, Tissue Damage, and Mortality in SARS-CoV-2 Infection and Cytokine Shock Syndromes
Rajendra Karki, Bhesh Raj Sharma, Shraddha Tuladhar, Evan Peter Williams, Lillian Zalduondo, Parimal Samir, Min Zheng, Balamurugan Sundaram, Balaji Banoth, R K Subbarao Malireddi, Patrick Schreiner, Geoffrey Neale, Peter Vogel , Richard Webby, Colleen Bet
Cell. 2021 Jan

COVID-19 is characterized by excessive production of pro-inflammatory cytokines and acute lung damage associated with patient mortality. While multiple inflammatory cytokines are produced by innate immune cells during SARS-CoV-2 infection, we found that only the combination of TNF-α and IFN-γ induced inflammatory cell death characterized by inflammatory cell death, PANoptosis. Mechanistically, TNF-α and IFN-γ co-treatment activated the JAK/STAT1/IRF1 axis, inducing nitric oxide production and driving caspase-8/FADD-mediated PANoptosis. TNF-α and IFN-γ caused a lethal cytokine shock in mice that mirrors the tissue damage and inflammation of COVID-19, and inhibiting PANoptosis protected mice from this pathology and death. Furthermore, treating with neutralizing antibodies against TNF-α and IFN-γ protected mice from mortality during SARS-CoV-2 infection, sepsis, hemophagocytic lymphohistiocytosis, and cytokine shock. Collectively, our findings suggest that blocking the cytokine-mediated inflammatory cell death signaling pathway identified here may benefit patients with COVID-19 or other infectious and autoinflammatory diseases by limiting tissue damage/inflammation. Keywords: COVID-19, SARS-CoV-2, inflammation, cytokine storm, TNF-α, IFN-γ, pyroptosis, apoptosis, necroptosis, PANoptosis