Kenyan Bat Coronavirus Identified Using Human Lung Receptor CEACAM6 for Potential Zoonotic Spillover

Researchers find a Kenyan bat coronavirus that binds to human lung receptors, raising new concerns about animal-to-human viral spillover.

By: AXL Media

Published: Apr 24, 2026, 5:53 AM EDT

Source: Information for this report was sourced from Nature

New Path for Viral Entry into Human Respiratory Systems

A study published in the journal Nature has identified a novel mechanism by which a bat-borne alpha-coronavirus, specifically BtCoV-KY43, can infect human cells. Unlike the better-known SARS-CoV-2, which uses the ACE2 receptor, this virus from Kenyan heart-nosed bats utilizes the human carcinoembryonic antigen cell adhesion molecule 6, or CEACAM6, to gain entry. This discovery is significant because it demonstrates that the barriers preventing animal viruses from jumping to humans are more porous than previously understood, particularly through receptors that are highly prevalent in human respiratory tissues.

Screening the Diversity of Alpha-Coronavirus Spike Proteins

To evaluate the risk of various viruses, the research team utilized a greedy algorithm to select 40 spike protein sequences that represented over half of the known phylogenetic diversity of alpha-coronaviruses. Many of these sequences originated from poorly characterized bat species. By creating synthetic versions of these proteins and testing them against libraries of mammalian receptors, the scientists found that the majority did not use common receptors like ACE2 or APN. This prompted a deeper investigation into which specific human molecules might be vulnerable to these less-studied viral threats.

Mapping CEACAM6 Expression Across Human Tissues

Using data from the Human Cell Atlas, researchers determined that CEACAM6 is expressed more ubiquitously in the human lung than any other known proteinaceous coronavirus receptor. High concentrations of the molecule were found in lung epithelial cells, type 1 alveolar cells, and goblet cells, all of which are primary targets for respiratory infections. The study utilized crystallography to pinpoint exactly how the viral spike protein binds to the amino-terminal domain of CEACAM6, confirming a high-affinity interaction that facilitates efficient cell entry in experimental settings.