Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged at the end of 2019 and caused the pandemic of coronavirus disease 2019 (COVID-19). Basic and clinical investigations indicate that severe forms of COVID-19 are due in part to dysregulated immune responses to virus infection. The innate immune system is the first line of host defense against most virus infections, with pathogen recognition receptors detecting SARS-CoV-2 RNA and protein components and initiating pro-inflammatory and antiviral responses. Notwithstanding this response, SARS-CoV-2 proteins evade, inhibit, and skew innate immune signaling early in infection. In this review, we highlight the components of cell-based recognition of SARS-CoV-2 infection and the mechanisms employed by the virus to modulate these innate immune host defense pathways.
