Discovery of the CARDIB Protein in Sea Anemones
Research led by doctoral student Tom Sharoni and Professor Yehu Moran from the Hebrew University of Jerusalem, in collaboration with colleagues at the University of North Carolina at Charlotte, challenges the long-held belief that all animals share a single antiviral defense system. Published in the journal Nature Ecology & Evolution, the study identifies a novel protein called CARDIB found in sea anemones. Unlike the MAVS protein, which serves as a critical immune defender in humans and other vertebrates, CARDIB functions as an immune suppressor. This finding reshapes our understanding of how immune systems have evolved across different species.
How CARDIB Works
The scientists examined sea anemones, which split from the human evolutionary lineage over 600 million years ago. While the CARDIB protein resembles human MAVS in structure, its role is markedly different. The team discovered that CARDIB acts as a brake on the immune response, helping anemones maintain a delicate balance between fighting off pathogens and tolerating viruses.
To test CARDIB's function, the researchers used CRISPR gene-editing technology to remove the protein's gene from anemones. Experiments revealed that without the CARDIB gene, these animals became more susceptible to infections, as viruses replicated faster inside them. The modified anemones were placed in natural estuarine water in South Carolina, and within days, individuals lacking CARDIB had accumulated significantly more viruses than their normal counterparts.
These results indicate that antiviral systems evolved independently across different animal groups, highlighting the diversity and complexity of immune responses in living organisms. The study opens new avenues for understanding the evolutionary mechanisms of immunity and could inform future scientific research in this field.
“Studying the CARDIB protein in sea anemones could fundamentally change how we view immunity, not only in invertebrates but also in vertebrates, including humans.”
Researchers
The findings underscore the importance of evolutionary biology in developing novel antiviral strategies and therapies. They may also enhance our ability to combat viral diseases in the future by providing valuable new data for research in this area.