A trade‐off model for immunocompetence: The potential contribution of immunological regulation in invasive vertebrate success. Issue 9 (7th August 2019)

• Record Type: Journal Article
• Authors: Poirier, Marie‐Véronique
• Is Part Of: Journal of experimental zoology. Volume 331:Issue 9(2019)
• Page Start: 478
• Page End: 484
• Publication Date: 2019-08-07
• Subjects: adaptive -- cell‐mediated -- ecoimmunology -- enemy‐release hypothesis -- fitness trade‐offs -- humoral -- immunocompetence -- inflammatory response -- innate -- invasive species; Zoology -- Periodicals; Zoology; Animal Population Groups -- physiology; Zoology; Electronic journals; Periodical; Periodicals; 590
• DOI: 10.1002/jez.2314
• Languages: English
• ISSNs: 2471-5646

Abstract

Abstract: Invasive species have become a prolific environmental issue, second only to climate change, yet many of the phenomena that facilitate invasive success are not well understood (Phillip & Shine, Proc. Roy. Soc. B, 273, 1545‐1550). The combination of several generalist life‐history traits, certain physiological mechanisms, and environmental conditions is thought to play a significant role in invasion success. The ability to undergo fitness trade‐offs—to reallocate nutritional and energetic resources towards processes that increase reproduction, growth, and dispersal—is also thought to be an adaptive quality of many invasive species. Due to their inherent flexibility, phenotypically plastic traits in particular are often targeted for fitness reallocations. Immune function, for example, is determined by a highly plastic phenotype, which is crucial for combating a diverse array of pathogens. When active, immune function also demands extensive resources from the host. Laboratory and field studies suggest that certain aspects of the immune system are more costly than others, though, and that its components can be regulated independent of one another. In invasive species undergoing fitness trade‐offs, costly innate inflammatory responses are often downregulated, while antibody‐mediated responses may be enhanced. A combination of fixed physiological responses and environmentally induced trade‐offs are thought to regulate the immune system, though the relationship between these facets of regulation is still an area of active research. The field of ecoimmunology, then, has emerged in effort to understand the phenomena by which individual immune regulation can drive (and be driven by) species‐level ecology and evolution, and therefore be linked to invasive success (Downs et al., 2014. Integr. Compar. Biol., 54, 340–352). Abstract : The ability to reallocate resources towards processes that drive reproduction, growth, and dispersal is thought to be an adaptive quality shared by many invasive species. Vertebrate immunity is characterized by high phenoplasticity and functions to promote survival against a diverse array foreign pathogens; however, non‐specific inflammatory processes can also be maladaptive. Different components of the immune system (innate, cell‐mediated, and humoral) are thought to require varying degrees of nutritional and energetic investment. In general, innate immunity is associated with the induction of costly inflammatory responses, whereas the antibody‐mediated humoral system is less resource‐intensive in its method of pathogenic attack (Lee & Klasing, 2004). Recent cross‐taxa studies suggest that selective regulation of immune system components ‐wherein more costly immune functions are down‐regulated in favor of up‐regulating more energetically‐efficient processes‐ may be contributing to invasive success. Research Highlights: Cross‐taxa studies suggest that selective regulation of immune system components ‐wherein more costly immune functions are down‐regulated in favor of up‐regulating more energetically‐efficient processes‐ may be contributing to invasive success.