April 24, 2020 / Modern Healthcare
Researchers have found two types of cells inside the nose express high levels of the genes encoding proteins the SARS-CoV-2 uses to enter cells, suggesting they are the likely entry points for the virus.
SARS-CoV-2, the virus that causes COVID-19, uses its spike protein to bind to cellular receptors in the human body. The virus relies on the ACE2 receptor protein and the TMPRSS2 protease to enter cells, but which cells are initially infected has been unclear. 
An international team of researchers used single-cell RNA sequencing datasets put together by the Human Cell Atlas consortium to search for cell types that express both the ACE2 and TMPRSS2 genes. As they reported in Nature Medicine on Thursday, they found a number of cells in different organs express the genes encoding these proteins, but they homed in on cells of the respiratory system, especially goblet cells and ciliated cells in the nose.