The effects of SARS-CoV-2 on susceptible human cells

The biological consequences of viral infection result from biochemical, physiological, structural, morphological and genetic changes in infected cells. In productive infections, virus-induced biological changes in cells may be closely related to the efficiency of viral replication or to the recognition of these cells by the immune system. These changes are usually associated with cytocidal viruses, as in the case of the pandemic coronavirus SARS-CoV-2, which causes COVID-19. Many of these changes are required for effective viral replication. The physiological state of living cells has a significant impact on the outcome of viral infection, as the host cell provides the synthetic machinery, key regulatory molecules and precursors for newly synthesised viral proteins and nucleic acids. This review focuses on novel target cell types for SARS-CoV-2 exposure outside the respiratory tract. Findings and examples are collected that provide information on virus-cell interactions. The identification of unusual target cells for SARS-CoV-2 may help to explain the diverse symptoms in COVID-19 patients and the long-lasting effects after infection. In particular, the discovery of previously undescribed target cells for SARS-CoV-2 action needs to be considered to improve treatment of patients and prevention of infection.