BMC Biology· 2026Q1
Harnessing variation in Drosophila melanogaster reveals different routes to increased infection susceptibility over age and sex-dependent association with lifespan
- 0citations
- Q1SCImago
- 2026year
Short summary
In fruit flies, increased susceptibility to infection with age is driven more by reduced disease tolerance than immune system decline, and this susceptibility predicts lifespan in males but not females.
AI-generated from the title and abstract; the full text is not read.
Key points
- Infection susceptibility increases early in life and is widespread across different fruit fly populations and infections.
- Reduced disease tolerance, rather than impaired immune resistance (immunosenescence), is the more frequent cause of increased susceptibility at old age.
- Increased susceptibility at old age predicts shorter lifespan in males but not in females.
- Infection susceptibility follows a power-law (Weibull) pattern with age, unlike the typical exponential (Gompertz) pattern for mortality.
AI-generated from the title and abstract; the full text is not read.
Abstract
Abstract Background It is widely accepted that susceptibility to infection increases with age, usually attributed to immune system dysregulation. However, factors beyond decreased resistance mechanisms may increase susceptibility, such as changes to physiological or metabolic processes determining overall tolerance, and this may differ between individuals. We hypothesised that age-related increases in susceptibility reflect changes in both immune system function and disease tolerance, with their relative importance varying by population and sex. Results We assessed age-related susceptibility to bacterial pathogens in an outbred Drosophila melanogaster population and 22 isolines. We leveraged this variation to investigate age-related infection susceptibility and lifespan and to estimate frequencies of declines in resistance or tolerance mechanisms. Susceptibility increased early in life and was widespread across infections and populations. Despite strong correlation between the sexes in baseline susceptibility and its decrease over age, susceptibility at old age did not correlate. Increased susceptibility was associated with impaired resistance ( bona fide immunosenescence), but more frequently with reduced tolerance, which could be detected early in life, and remained low. We find susceptibility at old age predicts lifespan in males only. Conclusions Increased infection susceptibility is an early-arising ageing phenotype occurring in both sexes and driving male mortality. Infection susceptibility followed a power-law (Weibull) rather than the exponential (Gompertz) pattern typical of mortality, with each doubling of age approximately doubling susceptibility. We argue that the term “immunosenescence” should be limited to dysregulation of resistance mechanisms, and consideration of population variation, sex, and ageing of non-immune functions is critical to fully understand age-related loss of pathogen control.
The authors' abstract, as published at the source. BMC Biology, 2026 · DOI ↗
Continue with a free account
Ask the paper: 3 free questions a day about this paper; save it, get its citation, new summaries every day for your field. Takeaways are Premium.
Continue free on the webSign in with Google or Apple; no card needed. You come back to this paper.
On your phone:
AgingBiochemistry, Genetics and Molecular Biology