Immunosenescence and the ability to survive @entity2348 in the XXXX @entity5399 .

@entity281 @entity11137 @entity2348 @entity5399
UNASSIGNED: In most animals, ageing is associated with a decline in immune function (immune senescence). However, different components of the immune system seem to age differentially, and many studies do not measure the ultimate fitness consequences of immune function after @entity281 . Previous work shows that immune function may be traded off with other fitness components such as reproduction. It is possible that age alters the nature of these trade-offs, particularly in conjunction with factors such as gender and mating that can also affect investment in immune function. We tested the impact of age, sex and mating on post- @entity281 survivorship in @entity5399 flour beetles, as well as the components of baseline constitutive innate immunity and external (secreted) immune function in uninfected individuals. We also tested whether the reproductive ability of uninfected females is traded off with immune function (baseline innate and external immunity) and post- @entity281 survivorship across age groups. We found that age, sex and mating significantly affected immune components and @entity281 outcome, although the magnitude and nature of the impact varied in each case. We found that older beetles were more susceptible to @entity281 by the pathogen @entity11137 even though major components of the constitutive innate immune defence (antibacterial and phenoloxidase activity) remained unchanged or improved with age. Thus, these aspects of innate immunity cannot explain the observed decline in post- @entity281 survival of older beetles. We did not find trade-offs between the reproductive ability of uninfected females and their immune function. In contrast to innate immunity, external immunity showed an overall decline with age but was also affected by sex and mating. Finally, we show that @entity2348 alters external immunity via complex interactions between age, sex and mating status. Our work uncovers novel interactions between age, sex and mating that can determine the evolution and outcome of immunosenescence by affecting the time course of relative investment in different immune and fitness components.
