Endothelial cells are not productively infected by SARS-CoV-2

Primary human endothelial cells express very low levels of ACE2 and TMPRSS2, both of which are important for SARS-CoV-2 infection. For the establishment of viral infection in the endothelial cells, very high concentration of SARS-CoV-2 virions is needed. Although it is likely that the endothelial cells do not contribute to the amplification of viral burden, these cells sense adjacent infection and produce pro-inflammatory cytokines, which may be involved in the acceleration of COVID-19 pathogenesis.