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Whiting-Fawcett F, Blomberg AS, Troitsky T, Meierhofer MB, Field KA, Puechmaille SJ, Lilley TM. A Palearctic view of a bat fungal disease. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024:e14265. [PMID: 38616727 DOI: 10.1111/cobi.14265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/02/2024] [Accepted: 01/20/2024] [Indexed: 04/16/2024]
Abstract
The fungal infection causing white-nose disease in hibernating bats in North America has resulted in dramatic population declines of affected species, since the introduction of the causative agent Pseudogymnoascus destructans. The fungus is native to the Palearctic, where it also infects several bat species, yet rarely causes severe pathology or the death of the host. Pseudogymnoascus destructans infects bats during hibernation by invading and digesting the skin tissue, resulting in the disruption of torpor patterns and consequent emaciation. Relations among pathogen, host, and environment are complex, and individuals, populations, and species respond to the fungal pathogen in different ways. For example, the Nearctic Myotis lucifugus responds to infection by mounting a robust immune response, leading to immunopathology often contributing to mortality. In contrast, the Palearctic M. myotis shows no significant immunological response to infection. This lack of a strong response, resulting from the long coevolution between the hosts and the pathogen in the pathogen's native range, likely contributes to survival in tolerant species. After more than 15 years since the initial introduction of the fungus to North America, some of the affected populations are showing signs of recovery, suggesting that the fungus, hosts, or both are undergoing processes that may eventually lead to coexistence. The suggested or implemented management methods of the disease in North America have encompassed, for example, the use of probiotics and fungicides, vaccinations, and modifying the environmental conditions of the hibernation sites to limit the growth of the pathogen, intensity of infection, or the hosts' responses to it. Based on current knowledge from Eurasia, policy makers and conservation managers should refrain from disrupting the ongoing evolutionary processes and adopt a holistic approach to managing the epizootic.
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Affiliation(s)
- F Whiting-Fawcett
- Department of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool, UK
- BatLab Finland, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - A S Blomberg
- BatLab Finland, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - T Troitsky
- BatLab Finland, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - M B Meierhofer
- BatLab Finland, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - K A Field
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, USA
| | - S J Puechmaille
- Institut des Sciences de l'Évolution Montpellier (ISEM), University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
- Institut Universitaire de France, Paris, France
| | - T M Lilley
- BatLab Finland, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
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2
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Kadamani KL, Logan SM, Pamenter ME. Does hypometabolism constrain innate immune defense? Acta Physiol (Oxf) 2024; 240:e14091. [PMID: 38288574 DOI: 10.1111/apha.14091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 11/30/2023] [Accepted: 01/01/2024] [Indexed: 02/24/2024]
Abstract
Many animals routinely make energetic trade-offs to adjust to environmental demands and these trade-offs often have significant implications for survival. For example, environmental hypoxia is commonly experienced by many organisms and is an energetically challenging condition because reduced oxygen availability constrains aerobic energy production, which can be lethal. Many hypoxia-tolerant species downregulate metabolic demands when oxygen is limited; however, certain physiological functions are obligatory and must be maintained despite the need to conserve energy in hypoxia. Of particular interest is immunity (including both constitutive and induced immune functions) because mounting an immune response is among the most energetically expensive physiological processes but maintaining immune function is critical for survival in most environments. Intriguingly, physiological responses to hypoxia and pathogens share key molecular regulators such as hypoxia-inducible factor-1α, through which hypoxia can directly activate an immune response. This raises an interesting question: do hypoxia-tolerant species mount an immune response during periods of hypoxia-induced hypometabolism? Unfortunately, surprisingly few studies have examined interactions between immunity and hypometabolism in such species. Therefore, in this review, we consider mechanistic interactions between metabolism and immunity, as well as energetic trade-offs between these two systems, in hypoxia-tolerant animals but also in other models of hypometabolism, including neonates and hibernators. Specifically, we explore the hypothesis that such species have blunted immune responses in hypometabolic conditions and/or use alternative immune pathways when in a hypometabolic state. Evidence to date suggests that hypoxia-tolerant animals do maintain immunity in low oxygen conditions, but that the sensitivity of immune responses may be blunted.
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Affiliation(s)
- Karen L Kadamani
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Samantha M Logan
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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3
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Wang Y, Wang X, Chen Y, Du J, Xiao Y, Guo D, Liu S. Adapting to stress: The effects of hibernation and hibernacula temperature on the hepatic transcriptome of Rhinolophus pusillus. FASEB J 2024; 38:e23462. [PMID: 38318662 DOI: 10.1096/fj.202301646r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/11/2023] [Accepted: 01/19/2024] [Indexed: 02/07/2024]
Abstract
Hibernation, a survival strategy in mammals for extreme climates, induces physiological phenomena such as ischemia-reperfusion and metabolic shifts that hold great potential for advancements in modern medicine. Despite this, the molecular mechanisms underpinning hibernation remain largely unclear. This study used RNA-seq and Iso-seq techniques to investigate the changes in liver transcriptome expression of Rhinolophus pusillus during hibernation and active periods, as well as under different microhabitat temperatures. We identified 11 457 differentially expressed genes during hibernation and active periods, of which 395 showed significant differential expression. Genes associated with fatty acid catabolism were significantly upregulated during hibernation, whereas genes related to carbohydrate metabolism and glycogen synthesis were downregulated. Conversely, immune-related genes displayed differential expression patterns: genes tied to innate immunity were significantly upregulated, while those linked to adaptive immunity and inflammatory response were downregulated. The analysis of transcriptomic data obtained from different microhabitat temperatures revealed that R. pusillus exhibited an upregulation of genes associated with lipid metabolism in lower microhabitat temperature. This upregulation facilitated an enhanced utilization rate of triglyceride, ultimately resulting in increased energy provision for the organism. Additionally, R. pusillus upregulated gluconeogenesis-related genes regardless of the microhabitat temperature, demonstrating the importance of maintaining blood glucose levels during hibernation. Our transcriptomic data reveal that these changes in liver gene expression optimize energy allocation during hibernation, suggesting that liver tissue adaptively responds to the inherent stress of its function during hibernation. This study sheds light on the role of differential gene expression in promoting more efficient energy allocation during hibernation. It contributes to our understanding of how liver tissue adapts to the stressors associated with this state.
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Affiliation(s)
- Ying Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Xufan Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yu Chen
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Jianying Du
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yanhong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Dongge Guo
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Sen Liu
- College of Life Sciences, Henan Normal University, Xinxiang, China
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Pikula J, Brichta J, Seidlova V, Piacek V, Zukal J. Higher antibody titres against Pseudogymnoascus destructans are associated with less white-nose syndrome skin lesions in Palearctic bats. Front Immunol 2023; 14:1269526. [PMID: 38143741 PMCID: PMC10739372 DOI: 10.3389/fimmu.2023.1269526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 11/28/2023] [Indexed: 12/26/2023] Open
Abstract
Introduction Serological tests can be used to test whether an animal has been exposed to an infectious agent, and whether its immune system has recognized and produced antibodies against it. Paired samples taken several weeks apart then document an ongoing infection and/or seroconversion. Methods In the absence of a commercial kit, we developed an indirect enzyme-linked immunosorbent assay (ELISA) to detect the fungus-specific antibodies for Pseudogymnoascus destructans, the agent of white-nose syndrome in bats. Results and Discussion Samples collected from European Myotis myotis (n=35) and Asian Myotis dasycneme (n=11) in their hibernacula at the end of the hibernation period displayed 100% seroprevalence of antibodies against P. destructans, demonstrating a high rate of exposure. Our results showed that the higher the titre of antibodies against P. destructans, the lower the infection intensity, suggesting that a degree of protection is provided by this arm of adaptive immunity in Palearctic bats. Moreover, P. destructans infection appears to be a seasonally self-limiting disease of Palearctic bats showing seroconversion as the WNS skin lesions heal in the early post-hibernation period.
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Affiliation(s)
- Jiri Pikula
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Brno, Czechia
- CEITEC: Central European Institute of Technology, University of Veterinary Sciences Brno, Brno, Czechia
| | - Jiri Brichta
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Brno, Czechia
| | - Veronika Seidlova
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Brno, Czechia
| | - Vladimir Piacek
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Brno, Czechia
| | - Jan Zukal
- Institute of Vertebrate Biology, Czech Academy of Sciences, Brno, Czechia
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Costantini D, Schad J, Czirják GÁ, Voigt CC. Oxidative damage varies in response to bacterial, fungal and viral antigen challenges in bats. J Exp Biol 2023; 226:jeb246332. [PMID: 37823235 DOI: 10.1242/jeb.246332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023]
Abstract
The immune system plays an important role in defending against pathogens and regulating physiological homeostasis, but the strength of the immune responses depends on the type of pathogen. The immune system of bats shows a high variability in responsiveness towards various pathogens; they can safely harbor certain pathogens that are highly lethal to other mammals. Oxidative stress may act as a pathophysiological cellular mechanism mediating the immunological function of bats because of its potentially detrimental effects on physiological homeostasis, fertility and longevity. By experimentally exposing greater mouse-eared bats (Myotis myotis) to three antigens, it was previously shown that animals reacted immunologically most strongly to bacterial and viral antigens, but not to fungal ones. As a follow up, in this study we observed that both bacterial and fungal antigens induced a significant increase of plasma oxidative damage, whereas viral antigens did not cause any increase of plasma oxidative damage at all albeit the mild immune response. Thus, experimental bats were able to avoid oxidative stress only in the face of a viral antigen, possibly by dampening inflammatory signalling. Bats may be able to handle viral infections and live well beyond expectations by reducing the detrimental effects of molecular oxidation.
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Affiliation(s)
- David Costantini
- Department of Ecological and Biological Sciences, Tuscia University, Largo dell'Università snc, 01100 Viterbo, Italy
| | - Julia Schad
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Gábor Á Czirják
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Christian C Voigt
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
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Harazim M, Perrot J, Varet H, Bourhy H, Lannoy J, Pikula J, Seidlová V, Dacheux L, Martínková N. Transcriptomic responses of bat cells to European bat lyssavirus 1 infection under conditions simulating euthermia and hibernation. BMC Immunol 2023; 24:7. [PMID: 37085747 PMCID: PMC10120247 DOI: 10.1186/s12865-023-00542-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/31/2023] [Indexed: 04/23/2023] Open
Abstract
BACKGROUND Coevolution between pathogens and their hosts decreases host morbidity and mortality. Bats host and can tolerate viruses which can be lethal to other vertebrate orders, including humans. Bat adaptations to infection include localized immune response, early pathogen sensing, high interferon expression without pathogen stimulation, and regulated inflammatory response. The immune reaction is costly, and bats suppress high-cost metabolism during torpor. In the temperate zone, bats hibernate in winter, utilizing a specific behavioural adaptation to survive detrimental environmental conditions and lack of energy resources. Hibernation torpor involves major physiological changes that pose an additional challenge to bat-pathogen coexistence. Here, we compared bat cellular reaction to viral challenge under conditions simulating hibernation, evaluating the changes between torpor and euthermia. RESULTS We infected the olfactory nerve-derived cell culture of Myotis myotis with an endemic bat pathogen, European bat lyssavirus 1 (EBLV-1). After infection, the bat cells were cultivated at two different temperatures, 37 °C and 5 °C, to examine the cell response during conditions simulating euthermia and torpor, respectively. The mRNA isolated from the cells was sequenced and analysed for differential gene expression attributable to the temperature and/or infection treatment. In conditions simulating euthermia, infected bat cells produce an excess signalling by multitude of pathways involved in apoptosis and immune regulation influencing proliferation of regulatory cell types which can, in synergy with other produced cytokines, contribute to viral tolerance. We found no up- or down-regulated genes expressed in infected cells cultivated at conditions simulating torpor compared to non-infected cells cultivated under the same conditions. When studying the reaction of uninfected cells to the temperature treatment, bat cells show an increased production of heat shock proteins (HSPs) with chaperone activity, improving the bat's ability to repair molecular structures damaged due to the stress related to the temperature change. CONCLUSIONS The lack of bat cell reaction to infection in conditions simulating hibernation may contribute to the virus tolerance or persistence in bats. Together with the cell damage repair mechanisms induced in response to hibernation, the immune regulation may promote bats' ability to act as reservoirs of zoonotic viruses such as lyssaviruses.
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Affiliation(s)
- Markéta Harazim
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 60300, Brno, Czechia.
- Department of Botany and Zoology, Masaryk University, Kotlářská 2, 61137, Brno, Czechia.
| | - Juliette Perrot
- Institut Pasteur, Université Paris Cité Lyssavirus, Epidemiology and Neuropathology Unit, 28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Hugo Varet
- Institut Pasteur, Université Paris Cité Bioinformatics and Biostatistics Hub, 28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Hervé Bourhy
- Institut Pasteur, Université Paris Cité Lyssavirus, Epidemiology and Neuropathology Unit, 28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Julien Lannoy
- Institut Pasteur, Université Paris Cité Lyssavirus, Epidemiology and Neuropathology Unit, 28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Jiri Pikula
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Palackého třída 1946/1, 61242, Brno, Czechia
| | - Veronika Seidlová
- Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences Brno, Palackého třída 1946/1, 61242, Brno, Czechia
| | - Laurent Dacheux
- Institut Pasteur, Université Paris Cité Lyssavirus, Epidemiology and Neuropathology Unit, 28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Natália Martínková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 60300, Brno, Czechia
- RECETOX, Masaryk University, Kotlářská 2, 61137, Brno, Czechia
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Differences in acute phase response to bacterial, fungal and viral antigens in greater mouse-eared bats (Myotis myotis). Sci Rep 2022; 12:15259. [PMID: 36088405 PMCID: PMC9464231 DOI: 10.1038/s41598-022-18240-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 08/08/2022] [Indexed: 11/15/2022] Open
Abstract
The acute phase response (APR) is an evolutionarily well-conserved part of the innate immune defense against pathogens. However, recent studies in bats yielded surprisingly diverse results compared to previous APR studies on both vertebrate and invertebrate species. This is especially interesting due to the known role of bats as reservoirs for viruses and other intracellular pathogens, while being susceptible to extracellular microorganisms such as some bacteria and fungi. To better understand these discrepancies and the reservoir-competence of bats, we mimicked bacterial, viral and fungal infections in greater mouse-eared bats (Myotis myotis) and quantified different aspects of the APR over a two-day period. Individuals reacted most strongly to a viral (PolyI:C) and a bacterial (LPS) antigen, reflected by an increase of haptoglobin levels (LPS) and an increase of the neutrophil-to-lymphocyte-ratio (PolyI:C and LPS). We did not detect fever, leukocytosis, body mass loss, or a change in the overall functioning of the innate immunity upon challenge with any antigen. We add evidence that bats respond selectively with APR to specific pathogens and that the activation of different parts of the immune system is species-specific.
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Shokrani H, Shokrani A, Jouyandeh M, Seidi F, Gholami F, Kar S, Munir MT, Kowalkowska-Zedler D, Zarrintaj P, Rabiee N, Saeb MR. Green Polymer Nanocomposites for Skin Tissue Engineering. ACS APPLIED BIO MATERIALS 2022; 5:2107-2121. [PMID: 35504039 DOI: 10.1021/acsabm.2c00313] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fabrication of an appropriate skin scaffold needs to meet several standards related to the mechanical and biological properties. Fully natural/green scaffolds with acceptable biodegradability, biocompatibility, and physiological properties quite often suffer from poor mechanical properties. Therefore, for appropriate skin tissue engineering and to mimic the real functions, we need to use synthetic polymers and/or additives as complements to green polymers. Green nanocomposites (either nanoscale natural macromolecules or biopolymers containing nanoparticles) are a class of scaffolds with acceptable biomedical properties window (drug delivery and cardiac, nerve, bone, cartilage as well as skin tissue engineering), enabling one to achieve the required level of skin regeneration and wound healing. In this review, we have collected, summarized, screened, analyzed, and interpreted the properties of green nanocomposites used in skin tissue engineering and wound dressing. We particularly emphasize the mechanical and biological properties that skin cells need to meet when seeded on the scaffold. In this regard, the latest state of the art studies directed at fabrication of skin tissue and bionanocomposites as well as their mechanistic features are discussed, whereas some unspoken complexities and challenges for future developments are highlighted.
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Affiliation(s)
- Hanieh Shokrani
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, 210037 Nanjing, China
| | - Amirhossein Shokrani
- Department of Mechanical Engineering, Sharif University of Technology, 11155-9567 Tehran, Iran
| | - Maryam Jouyandeh
- Center of Excellence in Electrochemistry, School of Chemistry, College of Science, University of Tehran, 11155-4563 Tehran, Iran
| | - Farzad Seidi
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, 210037 Nanjing, China
| | - Fatemeh Gholami
- New Technologies - Research Centre, University of West Bohemia, Veleslavínova 42, 301 00 Plzeň, Czech Republic
| | - Saptarshi Kar
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait
| | - Muhammad Tajammal Munir
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait
| | - Daria Kowalkowska-Zedler
- Department of Inorganic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, G. Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Payam Zarrintaj
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, United States
| | - Navid Rabiee
- Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran 145888-9694, Iran.,School of Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Mohammad Reza Saeb
- Department of Polymer Technology, Faculty of Chemistry, Gdańsk University of Technology, G. Narutowicza 11/12, 80-233 Gdańsk, Poland
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Costantini D. A meta-analysis of impacts of immune response and infection on oxidative status in vertebrates. CONSERVATION PHYSIOLOGY 2022; 10:coac018. [PMID: 35492421 PMCID: PMC9040321 DOI: 10.1093/conphys/coac018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/24/2022] [Accepted: 03/11/2022] [Indexed: 05/06/2023]
Abstract
Inferring from patterns observed in biomedical research, ecoimmunological theory predicts that oxidative stress is a ubiquitous physiological cost that contributes to generating variation in immune function between individuals or species. This prediction is, however, often challenged by empirical studies testing the relationship between immune response or infection and oxidative status markers. This points out the importance of combining ecological immunology and oxidative stress ecology to further our understanding of the proximate causes and fitness consequences of individual variation in health, and adaptability to natural and anthropogenic environmental changes. I reviewed evidence and performed phylogenetic meta-analyses of changes in oxidative status markers owing to either injection of an antigen or infection in captive and free-living vertebrates (141 studies, 1262 effect sizes, 97 species). The dataset was dominated by studies on fish, birds and mammals, which provided 95.8% of effect sizes. Both antigen injection and parasite exposure were associated with changes of oxidative status. There were significant effects of taxonomic class and experimental environment (captivity vs. wild). In contrast with my predictions, age category (young vs. adult), study design (correlational vs. experimental) and proxies of pace of life (clutch size, litter size, and body mass; for birds and mammals only) were negligible in this dataset. Several methodological aspects (type of immunostimulant, laboratory assay, tissue analysed) showed significant effects on both strength and direction of effect. My results suggest that alterations of oxidative status are a widespread consequence of immune function across vertebrates. However, this work also identified heterogeneity in strength and direction of effect sizes, which suggests that immune function does not necessarily result in oxidative stress. Finally, this work identifies methodological caveats that might be relevant for the interpretation and comparability of results and for the application in conservation programs.
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Affiliation(s)
- David Costantini
- Unité Physiologie Moléculaire et Adaptation, UMR 7221, Muséum National d’Histoire Naturelle, CNRS, CP32, 57 rue Cuvier 75005 Paris, France
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10
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Costantini D, Weinberg M, Jordán L, Moreno KR, Yovel Y, Czirják GÁ. Induced bacterial sickness causes inflammation but not blood oxidative stress in Egyptian fruit bats ( Rousettus aegyptiacus). CONSERVATION PHYSIOLOGY 2022; 10:coac028. [PMID: 35492418 PMCID: PMC9042053 DOI: 10.1093/conphys/coac028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/09/2022] [Accepted: 04/05/2022] [Indexed: 05/14/2023]
Abstract
Bats are particularly interesting vertebrates in their response to pathogens owing to extremes in terms of tolerance and resistance. Oxidation is often a by-product of processes involved in the acute phase response, which may result in antimicrobial or self-damaging effects. We measured the immunological and oxidative status responses of Egyptian fruit bats (Rousettus aegyptiacus) to a simulated bacterial infection using lipopolysaccharide injection. As expected, experimental bats exhibited increases in two humoral immunological markers. However, they surprisingly did not show any effects across two markers of oxidative damage and four antioxidant markers. We propose that this lack of effects on oxidative status may be due to a reduction in cell metabolism through sickness behaviours or given life history traits, such as a long lifespan and a frugivorous diet. Finally, the consistency in the pattern of elevation in haptoglobin and lysozyme between current and previous findings highlights their utility as diagnostic markers for extracellular infections in bats.
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Affiliation(s)
- David Costantini
- Corresponding author: Unité Physiologie Moléculaire et Adaptation, UMR 7221, Muséum National d’Histoire Naturelle, CNRS, CP32, 57 rue Cuvier 75005 Paris, France. Tel: 0033(0)140795374,
| | - Maya Weinberg
- Department of Zoology, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Lilla Jordán
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany
- Behavioural Ecology Group, Department of Systematic Zoology and Ecology, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary
| | - Kelsey R Moreno
- Department of Zoology, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Yossi Yovel
- Department of Zoology, Tel Aviv University, 6997801 Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany
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11
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Butler MW, Stierhoff EN, Carpenetti JM, Bertone MA, Addesso AM, Knutie SA. Oxidative damage increases with degree of simulated bacterial infection, but not ectoparasitism, in tree swallow nestlings. J Exp Biol 2021; 224:272162. [PMID: 34427672 DOI: 10.1242/jeb.243116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/18/2021] [Indexed: 11/20/2022]
Abstract
The purpose of mounting an immune response is to destroy pathogens, but this response comes at a physiological cost, including the generation of oxidative damage. However, many studies on the effects of immune challenges employ a single high dose of a simulated infection, meaning that the consequences of more mild immune challenges are poorly understood. We tested whether the degree of immunological challenge in tree swallows (Tachycineta bicolor) affects oxidative physiology and body mass, and whether these metrics correlate with parasitic nest mite load. We injected 14 day old nestlings with 0, 0.01, 0.1 or 1 mg lipopolysaccharide (LPS) per kg body mass, then collected a blood sample 24 h later to quantify multiple physiological metrics, including oxidative damage (i.e. d-ROMs), circulating amounts of triglyceride and glycerol, and levels of the acute phase protein haptoglobin. After birds had fledged, we identified and counted parasitic nest mites (Dermanyssus spp. and Ornithonyssus spp.). We found that only nestlings injected with 1 mg LPS kg-1 body mass, which is a common dosage in ecoimmunological studies, lost more body mass than individuals from other treatment groups. However, every dose of LPS resulted in a commensurate increase in oxidative damage. Parasitic mite abundance had no effect on oxidative damage across treatments. The amount of oxidative damage correlated with haptoglobin levels, suggesting compensatory mechanisms to limit self-damage during an immune response. We conclude that while only the highest-intensity immune challenges resulted in costs related to body mass, even low-intensity immune challenges result in detectable increases in oxidative damage.
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Affiliation(s)
| | | | | | - Matthew A Bertone
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Alyssa M Addesso
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Sarah A Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA.,Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
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12
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Eskew EA, Fraser D, Vonhof MJ, Pinsky ML, Maslo B. Host gene expression in wildlife disease: making sense of species-level responses. Mol Ecol 2021; 30:6517-6530. [PMID: 34516689 DOI: 10.1111/mec.16172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 08/16/2021] [Accepted: 08/31/2021] [Indexed: 12/11/2022]
Abstract
Emerging infectious diseases are significant threats to wildlife conservation, yet the impacts of pathogen exposure and infection can vary widely among host species. As such, conservation biologists and disease ecologists have increasingly aimed to understand species-specific host susceptibility using molecular methods. In particular, comparative gene expression assays have been used to contrast the transcriptomic responses of disease-resistant and disease-susceptible hosts to pathogen exposure. This work usually assumes that the gene expression responses of disease-resistant species will reveal the activation of molecular pathways contributing to host defence. However, results often show that disease-resistant hosts undergo little gene expression change following pathogen challenge. Here, we discuss the mechanistic implications of these "null" findings and offer methodological suggestions for future molecular studies of wildlife disease. First, we highlight that muted transcriptomic responses with minimal immune system recruitment may indeed be protective for nonsusceptible hosts if they limit immunopathology and promote pathogen tolerance in systems where susceptible hosts suffer from genetic dysregulation. Second, we argue that overly narrow investigation of responses to pathogen exposure may overlook important, constitutively active molecular pathways that underlie species-specific defences. Finally, we outline alternative study designs and approaches that complement interspecific transcriptomic comparisons, including intraspecific gene expression studies and genomic methods to detect signatures of selection. Collectively, these insights will help ecologists extract maximal information from conservation-relevant transcriptomic data sets, leading to a deeper understanding of host defences and, ultimately, the implementation of successful conservation interventions.
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Affiliation(s)
- Evan A Eskew
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Department of Biology, Pacific Lutheran University, Tacoma, Washington, USA
| | - Devaughn Fraser
- Wildlife Genetics Research Laboratory, California Department of Fish and Wildlife, Sacramento, California, USA
| | - Maarten J Vonhof
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA
| | - Malin L Pinsky
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Brooke Maslo
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
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13
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Hudson SB, Virgin EE, Kepas ME, French SS. Energy expenditure across immune challenge severities in a lizard: consequences for innate immunity, locomotor performance and oxidative status. J Exp Biol 2021; 224:271845. [PMID: 34402514 DOI: 10.1242/jeb.242608] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/11/2021] [Indexed: 12/15/2022]
Abstract
Reptiles, like other vertebrates, rely on immunity to defend themselves from infection. The energetic cost of an immune response is liable to scale with infection severity, prompting constraints on other self-maintenance traits if immune prioritization exceeds energy budget. In this study, adult male side-blotched lizards (Uta stansburiana) were injected with saline (control) or high (20 µg g-1 body mass) or low (10 µg g-1 body mass) concentrations of lipopolysaccharide (LPS) to simulate bacterial infections of discrete severities. The costs and consequences of the immune response were assessed through comparisons of change in resting metabolic rate (RMR), energy metabolites (glucose, glycerol, triglycerides), innate immunity (bactericidal ability), sprint speed and oxidative status (antioxidant capacity, reactive oxygen metabolites). High-LPS lizards had the lowest glucose levels and greatest sprint reductions, while their RMR and bactericidal ability were similar to those of control lizards. Low-LPS lizards had elevated RMR and bactericidal ability, but glucose levels and sprint speed changes between those of high-LPS and control lizards. Levels of glycerol, triglycerides, reactive oxygen metabolites and antioxidant capacity did not differ by treatment. Taken together, energy expenditure for the immune response varies in a non-linear fashion with challenge severity, posing consequences for performance and self-maintenance processes in a reptile.
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Affiliation(s)
- Spencer B Hudson
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Emily E Virgin
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Megen E Kepas
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
| | - Susannah S French
- Department of Biology, Utah State University, Logan, UT 84322-5205, USA.,Ecology Center, Utah State University, Logan, UT 84322-5205, USA
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14
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Moreno KR, Weinberg M, Harten L, Salinas Ramos VB, Herrera M LG, Czirják GÁ, Yovel Y. Sick bats stay home alone: fruit bats practice social distancing when faced with an immunological challenge. Ann N Y Acad Sci 2021; 1505:178-190. [PMID: 33876431 PMCID: PMC9290741 DOI: 10.1111/nyas.14600] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 12/21/2022]
Abstract
Along with its many advantages, social roosting imposes a major risk of pathogen transmission. How social animals reduce this risk is poorly documented. We used lipopolysaccharide challenge to imitate bacterial infection in both a captive and a free‐living colony of an extremely social, long‐lived mammal—the Egyptian fruit bat. We monitored behavioral and physiological responses using an arsenal of methods, including onboard GPS to track foraging, acceleration sensors to monitor movement, infrared video to record social behavior, and blood samples to measure immune markers. Sick‐like (immune‐challenged) bats exhibited an increased immune response, as well as classic illness symptoms, including fever, weight loss, anorexia, and lethargy. Notably, the bats also exhibited behaviors that would reduce pathogen transfer. They perched alone and appeared to voluntarily isolate themselves from the group by leaving the social cluster, which is extremely atypical for this species. The sick‐like individuals in the open colony ceased foraging outdoors for at least two nights, thus reducing transmission to neighboring colonies. Together, these sickness behaviors demonstrate a strong, integrative immune response that promotes recovery of infected individuals while reducing pathogen transmission inside and outside the roost, including spillover events to other species, such as humans.
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Affiliation(s)
- Kelsey R Moreno
- Department of Zoology, Tel Aviv University, Tel Aviv, Israel
| | - Maya Weinberg
- Department of Zoology, Tel Aviv University, Tel Aviv, Israel
| | - Lee Harten
- Department of Zoology, Tel Aviv University, Tel Aviv, Israel
| | - Valeria B Salinas Ramos
- Department of Agriculture, University of Naples Federico II, Naples, Italy.,Estación de Biología Chamela, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - L Gerardo Herrera M
- Estación de Biología Chamela, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Yossi Yovel
- Department of Zoology, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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15
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Associating physiological functions with genomic variability in hibernating bats. Evol Ecol 2021. [DOI: 10.1007/s10682-020-10096-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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The immune response of bats differs between pre-migration and migration seasons. Sci Rep 2020; 10:17384. [PMID: 33060711 PMCID: PMC7562910 DOI: 10.1038/s41598-020-74473-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/03/2020] [Indexed: 12/21/2022] Open
Abstract
Maintaining a competent immune system is energetically costly and thus immunity may be traded against other costly traits such as seasonal migration. Here, we tested in long-distance migratory Nathusius’ pipistrelles (Pipistrellus nathusii), if selected branches of immunity are expressed differently in response to the energy demands and oxidative stress of aerial migration. During the migration period, we observed higher baseline lymphocyte and lower neutrophil levels than during the pre-migration period, but no stronger response of cellular effectors to an antigen challenge. Baseline plasma haptoglobin, as a component of the humoral innate immunity, remained similar during both seasons, yet baseline plasma haptoglobin levels increased by a factor of 7.8 in migratory bats during an immune challenge, whereas they did not change during the pre-migration period. Oxidative stress was higher during migration than during pre-migration, yet there was no association between blood oxidative status and immune parameters, and immune challenge did not trigger any changes in oxidative stress, irrespective of season. Our findings suggest that humoral effectors of the acute phase response may play a stronger role in the first-line defense against infections for migrating bats compared to non-migrating bats. We conclude that Nathusius’ pipistrelles allocate resources differently into the branches of their immune system, most likely following current demands resulting from tight energy budgets during migration.
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17
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Hecht-Höger AM, Braun BC, Krause E, Meschede A, Krahe R, Voigt CC, Greenwood AD, Czirják GÁ. Plasma proteomic profiles differ between European and North American myotid bats colonized by Pseudogymnoascus destructans. Mol Ecol 2020; 29:1745-1755. [PMID: 32279365 DOI: 10.1111/mec.15437] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/18/2022]
Abstract
Emerging fungal diseases have become challenges for wildlife health and conservation. North American hibernating bat species are threatened by the psychrophilic fungus Pseudogymnoascus destructans (Pd) causing the disease called white-nose syndrome (WNS) with unprecedented mortality rates. The fungus is widespread in North America and Europe, however, disease is not manifested in European bats. Differences in epidemiology and pathology indicate an evolution of resistance or tolerance mechanisms towards Pd in European bats. We compared the proteomic profile of blood plasma in healthy and Pd-colonized European Myotis myotis and North American Myotis lucifugus in order to identify pathophysiological changes associated with Pd colonization, which might also explain the differences in bat survival. Expression analyses of plasma proteins revealed differences in healthy and Pd-colonized M. lucifugus, but not in M. myotis. We identified differentially expressed proteins for acute phase response, constitutive and adaptive immunity, oxidative stress defence, metabolism and structural proteins of exosomes and desmosomes, suggesting a systemic response against Pd in North American M. lucifugus but not European M. myotis. The differences in plasma proteomic profiles between European and North American bat species colonized by Pd suggest European bats have evolved tolerance mechanisms towards Pd infection.
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Affiliation(s)
| | - Beate C Braun
- Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Eberhard Krause
- Leibniz Institute for Molecular Pharmacology, Berlin, Germany
| | - Angelika Meschede
- Institute of Zoology II, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - Christian C Voigt
- Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.,Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Alex D Greenwood
- Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.,Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Gábor Á Czirják
- Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
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18
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Armour EM, Bruner TL, Hines JK, Butler MW. Low-dose immune challenges result in detectable levels of oxidative damage. J Exp Biol 2020; 223:jeb220095. [PMID: 32054680 DOI: 10.1242/jeb.220095] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/10/2020] [Indexed: 08/26/2023]
Abstract
Infection can result in substantial costs to animals, so they frequently respond by removing infectious agents with an immune response. However, immune responses entail their own costs, including upregulation of processes that destroy pathogens (e.g. the production of reactive oxygen species) and processes that limit the extent of self-damage during the immune response (e.g. production of anti-inflammatory proteins such as haptoglobin). Here, we simulated bacterial infection across a 1000-fold range using lipopolysaccharide (LPS) administered to northern bobwhite quail (Colinus virginianus), and quantified metrics related to pro-inflammatory conditions [i.e. generation of oxidative damage (d-ROMs), depletion of antioxidant capacity], anti-inflammatory mechanisms (i.e. production of haptoglobin, expression of the enzyme heme oxygenase, production of the organic molecule biliverdin) and nutritional physiology (e.g. circulating triglyceride levels, maintenance of body mass). We detected increases in levels of haptoglobin and d-ROMs even at LPS doses that are 1/1000th the concentration of doses frequently used in ecoimmunological studies, while loss of body mass and decreases in circulating triglycerides manifested only in individuals receiving the highest dose of LPS (1 mg LPS kg-1 body mass), highlighting variation among dose-dependent responses. Additionally, individuals that lost body mass during the course of the experiment had lower levels of circulating triglycerides, and those with more oxidative damage had greater levels of heme oxygenase expression, which highlights the complex interplay between pro- and anti-inflammatory processes. Because low doses of LPS may simulate natural infection levels, variation in dose-dependent physiological responses may be particularly important in modeling how free-living animals navigate immune challenges.
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Affiliation(s)
- Ellen M Armour
- Department of Biology, Lafayette College, Easton, PA 18042, USA
| | - Taylor L Bruner
- Department of Chemistry, Lafayette College, Easton, PA 18042, USA
| | - Justin K Hines
- Department of Chemistry, Lafayette College, Easton, PA 18042, USA
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