Public health: Broad reception for coronavirus

Abstract

The discovery that a new coronavirus associated with lethal respiratory infections binds to an evolutionarily conserved receptor on airway cells suggests that direct transmission from bats to humans may occur. See Letter p.251

Figure 1. Interspecies transmission pathways for coronaviruses.

Raj and colleagues have identified the cell-surface protein DPP4 as the receptor for hCoV-EMC, a new coronavirus that causes severe respiratory infections in humans. DPP4 is expressed on non-ciliated cells in the human airway. The virus is also able to use the homologous protein in bats for infection, which suggests that direct and reversible transmission of the virus between bats and humans may occur (although transmission through an intermediate host remains a possibility). By contrast, another pathogenic coronavirus (SARS-CoV), which binds to the ACE2 receptor on ciliated airway cells, probably cannot be transmitted directly and is likely to have jumped from bats to humans through evolutionary processes in intermediate hosts, such as civet cats. Open arrows indicate putative routes of transmission, crosses indicate evidence against transmission and a question mark indicates speculation on transmission.