An international team of researchers has identified an East African bat coronavirus capable of entering human cells.
We found a new coronavirus receptor in human cells ahead of any virus spillover into the human population.
Giulia Gallo
The virus - Cardioderma cor coronavirus (CcCoV) KY43, or CcCoV-KY43 - can bind to a receptor cell found in the human lung, but testing in Kenya suggests it has not spilled over into the local human population.
Rather than work on 'live' viruses, the scientists used a public database of known genetic sequences, Genbank, to select and synthesise alphacoronavirus 'spike' proteins, including 27 viruses originally isolated in bats, and screened these against a library of coronavirus receptors found in human cells.
Spike proteins protrude from the surface of coronaviruses, including SARS-CoV-2, and bind to specific receptors on human cells, triggering infection.
Funded largely through UK Research and Innovation's Biotechnology and Biological Sciences Research Council (BBSRC) and Kenya Government's National Research Fund, the study brought together UK and Kenyan expertise to show CcCoV-KY43 binds to the human glycoprotein CEACAM6.
Writing in the journal Nature, the team from The Pirbright Institute, the University of Cambridge, the KEMRI-Wellcome Trust Research Programme, the University of York and the National Museums of Kenya say their findings show alphacoronaviruses (alphaCovs) can use various receptors to enter human cells.
"Viral spike proteins are keys that fit into locks (host receptors) to open the door and enter a cell. So far, we have identified one alphaCov receptor. The challenge now is to find the others," said Professor Stephen Graham in the Department of Pathology at the University of Cambridge, joint senior author of the paper.
"Before our study, it was assumed all alphacoronaviruses used just one of two possible receptors to enter their host, and the only difference was which species they could enter. We now know alphaCovs might use a whole variety of different receptors to open cells," said Dr Dalan Bailey, Group Leader at the Pirbright Institute and joint senior author of the paper.
"Not only did we find the new coronavirus receptor in human cells ahead of any virus spillover into the human population, but the study was performed using just a piece of the virus (the spike) rather than the whole pathogen, negating the need to import a live virus into the UK," said Dr Giulia Gallo, lead author of the paper who conducted the work at both the Pirbright Institute and the University of Cambridge.
CcCoV-KY43 is found in heart-nosed bats, Cardioderma cor, an ecologically important species found mainly in eastern Africa including in eastern Sudan and northern Tanzania.
The researchers say the zoonotic (animal-to-human) and pandemic potential of alphaCoVs has remained relatively unchartered - to date, only two cellular receptors have been characterized for alphaCoVs.
The work identifies the need for further study in East Africa to better understand the risk from the family of viruses that can use this receptor to enter human cells. This will help scientists to be better prepared for any spillover of the virus into humans in the future, and potentially begin to start developing human vaccines and antivirals. The team wants to apply the same computational technology used in this study to find other potential human pathogens, and also to understand the wider drivers of zoonotic potential.
Graham added: "We hope our findings will help better understand the risk from the family of viruses we identified that can use the human receptor: for example, by mapping the prevalence of the virus in bats and looking to see if it has already spilled over in at-risk populations."
Reference: Gallo, G. et al: 'Heart-nosed bat alphacoronaviruses use human CEACAM6 to enter cells.' Nature, April 2026.
Adapted from a press release by The Pirbright Institute.
