Fruit-only diet improves bats’ immune response to viruses

Fruit bats generate more diverse antibodies than mice, but overall have a weaker antibody response, according to a new study published September 24^th in the open-access journal PLOS Biology by Dan Crowley from Cornell University, USA, and colleagues.

Bats are well-known reservoirs for viruses with pandemic potential. While these viruses typically do not cause disease in bats, they can prove deadly in humans. Spillover events—transmission of a virus from a reservoir population (eg, bats) to a new host population (eg, humans)—have been linked to environmental changes such as food shortages, which may impact immune responses.

While previous studies have demonstrated that bats typically generate weaker antibody responses to viruses than other mammals, these studies used viruses that co-evolved with bats. Understanding the bat immune system, including antibody responses to well-characterized antigens, can lead to better understanding of the circumstances that lead to spillover and inform efforts to prevent future events.

In this study, researchers exposed fruit bats and mice to well-studied antigens. They found that bats generated a weaker, more diverse antibody response than mice. Because the antigens were designed to elicit specific types of immune responses, the results provide some insight on the mechanism behind the immune response, which could be explored in future studies.

The researchers also looked at how changes in diet impacted the bats’ antibody responses to an influenza A-like virus and a pseudotyped Nipah virus. Surprisingly, bats fed a fruit-only diet had a stronger antibody response—demonstrated by higher antibody levels and better binding antibodies—compared to those fed a protein-supplemented diet.

The findings demonstrate that fruit bats generate a less robust antibody response than mice that can be improved by changes in diet. Future studies could inform whether this is generalizable across other bat species.

The authors add, “Bats, known reservoirs of zoonotic viruses, can produce weak antibody responses to infections. Our research shows that changing the dietary protein of Jamaican fruit bats can enhance their antibody response to certain viruses.”

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In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3002800

Citation: Crowley DE, Falvo CA, Benson E, Hedges J, Jutila M, Ezzatpour S, et al. (2024) Bats generate lower affinity but higher diversity antibody responses than those of mice, but pathogen-binding capacity increases if protein is restricted in their diet. PLoS Biol 22(9): e3002800. https://doi.org/10.1371/journal.pbio.3002800

Author Countries: United States

Funding: This work was supported by National Science Foundation (Rules of Life scheme EF-2133763/EF-2231624 to ARA and RKP, Coupled Natural Human Systems DEB-1716698 to RKP), Defense Advanced Research Projects Agency (PREEMPT program Cooperative Agreement D18AC00031 to RKP, ARA, TS), National Institutes of Health (R01 AI134768 to WM & TS and R01 AI109022 to HCA). The content of the information does not necessarily reflect the position or the policy of the U.S. government, and no official endorsement should be inferred. Funders played no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.