Bat antiviral mechanisms reveal unique defenses against viruses

Research into bat biology is uncovering unique mechanisms that allow these animals to act as reservoirs for zoonotic viruses, such as coronaviruses, without succumbing to illness.

One study indicates that bat cells utilize the Dicer enzyme to process viral genomic RNAs during SARS-CoV-2 infection. By generating small-interfering RNA (siRNA)-like fragments, bats may be able to limit viral replication in a manner not observed in other mammals. This process involves the upregulation of OAS1 and MX1, suggesting an antiviral defense strategy that differs from the common PKR-based systems found in other species.

Complementary research has focused on the development of primary cell cultures from New World bat species, including Sturnira parvidens, Glossophaga mutica, Molossus nigricans, and Tadarida brasiliensis. These studies aim to understand how physiological stressors, such as cortisol, influence immunity and viral replication. While cortisol did not significantly alter viral replication in certain tests, it was found to modulate antiviral gene expression in a species-dependent manner, providing new models for studying how viruses might spill over from bats to other species.