Murine-β-coronavirus-induced neuropathogenesis sheds light on CNS pathobiology of SARS-CoV2

The pandemic caused by SARS-CoV-2 has caused widespread infection and significant mortality across the globe. Combined virology perspective of SARS-CoV-2 with a deep-rooted understanding of pathophysiological and immunological processes underlying the clinical manifestations of COVID-19 is of prime importance. The characteristic symptom of COVID-19 is respiratory distress with diffused alveolar damage, but emerging evidence suggests COVID-19 might also have neurologic consequences. Dysregulated homeostasis in the lungs has proven to be fatal, but one cannot ignore that the inability to breathe might be due to defects in the respiratory control center of the brainstem. While the mechanism of pulmonary distress has been documented in the literature, awareness of neurological features and their pathophysiology is still in the nascent state. This review makes references to the neuro-immune axis and neuro-invasive potential of SARS-CoV and SARS-CoV2, as well as the prototypic H-CoV strains in human brains. Simultaneously, considerable discussion on relevant experimental evidence of mild to severe neurological manifestations of fellow neurotropic murine-β-CoVs (m-CoVs) in the mouse model will help understand the underpinning mechanisms of Neuro-COVID. In this review, we have highlighted the neuroimmunopathological processes in murine CoVs. While MHV infection in mice and SARS-CoV-2 infection in humans share numerous parallels, there are critical differences in viral recognition and viral entry. These similarities are highlighted in this review, while differences have also been emphasized. Though CoV-2 Spike does not favorably interact with murine ACE2 receptor, modification of murine SARS-CoV2 binding domain or development of transgenic ACE-2 knock-in mice might help in mediating consequential infection and understanding human CoV2 pathogenesis in murine models. While a global animal model that can replicate all aspects of the human disease remains elusive, prior insights and further experiments with fellow m-β-CoV-induced cause-effect experimental models and current human COVID-19 patients data may help to mitigate the SARS-CoV-2-induced multifactorial multi-organ failure