The Impact of Age on Response to Infection in Drosophila

Abstract

This review outlines the known cellular pathways and mechanisms involved in Drosophila age-dependent immunity to pathogenic microorganisms such as bacteria and fungi. We discuss the implication of host signaling pathways such as the Toll, Immune Deficiency (IMD), Janus kinase signal transducer and activator of transcription (JAK/STAT), and Insulin/Insulin Growth Factor/Target of Rapamycin (IIS/TOR) on immune function with aging. Additionally, we review the effects that factors such as sexual dimorphism, environmental stress, and cellular physiology exert on age-dependent immunity in Drosophila. We discuss potential tradeoffs between heightened immune function and longevity in the absence of infection, and we provide detailed tables outlining the various assays and pathogens used in the cited studies, as well as the age, sex, and strains of Drosophila used. We also discuss the overlapping effects these pathways and mechanisms have on one another. We highlight the great utility of Drosophila as a model organism and the importance of a greater focus on age-dependent antiviral immunity for future studies.

Host condition and pathogen identity influence bacterial infection survival in the common eastern firefly,Photinus pyralis

“…This likely reflects the age of fireflies collected at each time in the season, as fireflies collected earlier in the season are all newly eclosed and young while later collections have a mix of older and younger fireflies. The interaction that we observed between infection and season day is reminiscent of the aging effect seen across the animal kingdom including in other insect species where older individuals are generally more susceptible to infection (Armitage et al, 2003;Armitage & Boomsma, 2010;Fisher & Hajek, 2016;Khan et al, 2016;Lourenço et al, 2019;Park et al, 2011;Pu et al, 2021;Roberts & Hughes, 2014;Sciambra & Chtarbanova, 2021;Zerofsky et al, 2005).…”

“…Although work in fruit flies and other lab-adapted insect species has uncovered many mechanisms that contribute to immunosenescence (Sciambra & Chtarbanova, 2021), aging studies in non-model systems will be incredibly important to our understanding of the interaction between infection and aging (Guo et al, 2020).…”

Fly immunity comes of age: The utility of Drosophila as a model for studying variation in immunosenescence

“…Here, we have briefly detailed the contributions of the model to three, interconnected disciplines. The power, we argue, in using Drosophila as a model in immunosenescence, which shares many similarities with that of mammals and has been reviewed elsewhere (Flatt and Garschall, 2018;Min and Tatar, 2018;Sciambra and Chtarbanova, 2021), comes from the conceptual and technical convergence of these fields on the system (Figure 1). Coupling the genetic and technical approaches possible in Drosophila with an evolutionary biology approach to address different forms of variation in immune responses will not only provide mechanistic insights into immunosenescence, but will also guide our ultimate goal of treating it.…”

RNA virus-mediated changes in organismal oxygen consumption rate in young and old Drosophila melanogaster males

“…Subsequently, 20 out of 40 flies from each of the 3 groups of 2 vials were subjected to one of the three treatment protocols, resulting in 20 Non-injected (Ni), 20 Tris-injected (Tris) and 20 FHV-injected (FHV) flies. Anesthetized flies were sequentially placed in randomly labeled vials (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) for the corresponding treatment (FHV, Tris or Ni). Numbered treatment labels were subsequently replaced with a random vial identification number (e.g., v1 -v60) (Figure 1A and Supplementary Table 1).…”