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Weston K, Fulton JE, Owen J. Antigen specificity affects analysis of natural antibodies. Front Immunol 2024; 15:1448320. [PMID: 39170611 PMCID: PMC11335478 DOI: 10.3389/fimmu.2024.1448320] [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: 06/13/2024] [Accepted: 07/22/2024] [Indexed: 08/23/2024] Open
Abstract
Natural antibodies are used to compare immune systems across taxa, to study wildlife disease ecology, and as selection markers in livestock breeding. These immunoglobulins are present prior to immune stimulation. They are described as having low antigen specificity or polyreactive binding and are measured by binding to self-antigens or novel exogenous proteins. Most studies use only one or two antigens to measure natural antibodies and ignore potential effects of antigen specificity in analyses. It remains unclear how different antigen-specific natural antibodies are related or how diversity among natural antibodies may affect analyses of these immunoglobulins. Using genetically distinct lines of chickens as a model system, we tested the hypotheses that (1) antigen-specific natural antibodies are independent of each other and (2) antigen specificity affects the comparison of natural antibodies among animals. We used blood cell agglutination and enzyme-linked immunosorbent assays to measure levels of natural antibodies binding to four antigens: (i) rabbit erythrocytes, (ii) keyhole limpet hemocyanin, (iii) phytohemagglutinin, or (iv) ovalbumin. We observed that levels of antigen specific natural antibodies were not correlated. There were significant differences in levels of natural antibodies among lines of chickens, indicating genetic variation for natural antibody production. However, line distinctions were not consistent among antigen specific natural antibodies. These data show that natural antibodies are a pool of relatively distinct immunoglobulins, and that antigen specificity may affect interpretation of natural antibody function and comparative immunology.
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Affiliation(s)
- Kendra Weston
- Department of Entomology, Washington State University, Pullman, WA, United States
| | | | - Jeb Owen
- Department of Entomology, Washington State University, Pullman, WA, United States
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2
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Ravindran S, Underwood SL, Dorrens J, Seeker LA, Watt K, Wilbourn RV, Sparks AM, Sinclair R, Chen Z, Pilkington JG, McNeilly TN, Harrington L, Pemberton JM, Nussey DH, Froy H. No correlative evidence of costs of infection or immunity on leucocyte telomere length in a wild population of Soay sheep. Proc Biol Sci 2024; 291:20232946. [PMID: 38565156 PMCID: PMC10987235 DOI: 10.1098/rspb.2023.2946] [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: 12/29/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Telomere length (TL) is a biomarker hypothesized to capture evolutionarily and ecologically important physiological costs of reproduction, infection and immunity. Few studies have estimated the relationships among infection status, immunity, TL and fitness in natural systems. The hypothesis that short telomeres predict reduced survival because they reflect costly consequences of infection and immune investment remains largely untested. Using longitudinal data from a free-living Soay sheep population, we tested whether leucocyte TL was predicted by infection with nematode parasites and antibody levels against those parasites. Helminth parasite burdens were positively associated with leucocyte TL in both lambs and adults, which is not consistent with TL reflecting infection costs. We found no association between TL and helminth-specific IgG levels in either young or old individuals which suggests TL does not reflect costs of an activated immune response or immunosenescence. Furthermore, we found no support for TL acting as a mediator of trade-offs between infection, immunity and subsequent survival in the wild. Our results suggest that while variation in TL could reflect short-term variation in resource investment or environmental conditions, it does not capture costs of infection and immunity, nor does it behave like a marker of an individual's helminth-specific antibody immune response.
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Affiliation(s)
- Sanjana Ravindran
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Sarah L. Underwood
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Jennifer Dorrens
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Luise A. Seeker
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Kathryn Watt
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Rachael V. Wilbourn
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Alexandra M. Sparks
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Rona Sinclair
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Zhulin Chen
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Jill G. Pilkington
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Tom N. McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik EH26 0PZ, UK
| | - Lea Harrington
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada H3C 3J7
| | - Josephine M. Pemberton
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Daniel H. Nussey
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Hannah Froy
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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3
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Nelson-Flower MJ, Grieves LA, Reid JM, Germain RR, Lazic S, Taylor SS, MacDougall-Shackleton EA, Arcese P. Immune genotypes, immune responses, and survival in a wild bird population. Mol Ecol 2023. [PMID: 36919652 DOI: 10.1111/mec.16923] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 02/18/2023] [Accepted: 03/02/2023] [Indexed: 03/16/2023]
Abstract
Individuals vary in their immune genotype, inbreeding coefficient f, immune responses, survival to adulthood, and adult longevity. However, whether immune genes predict survival or longevity, whether such relationships are mediated through immune responses, and how f affects immune genotype remain unclear. We use a wild song sparrow (Melospiza melodia) population in which survival to adulthood, adult longevity, and f were measured precisely, and in which immune responses have previously been assessed. We investigate four toll-like receptor (TLR) and the major histocompatibility complex (MHC) class IIB exon 2 genes. We test whether immune genes predict fitness (survival to adulthood or adult longevity); whether immune genes predict immune response; whether immune response predicts fitness and whether fitness, immune responses, or immune genotypes are correlated with f. We find that survival to adulthood is not associated with immune gene variation, but adult longevity is decreased by high MHC allele diversity (especially in birds that were relatively outbred), and by the presence of a specific MHC supertype. Immune responses were affected by specific immune genotypes. Survival to adulthood and adult longevity were not predicted by immune response, implying caution in the use of immune response as a predictor for fitness. We also found no relationship between f and immune genotype. This finding indicates that immune gene associations with longevity and immune response are not artefacts of f, and suggests that pathogen-mediated selection at functional loci can slow the loss of genetic variation arising from genetic drift and small population size.
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Affiliation(s)
- Martha J Nelson-Flower
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biology, Langara College, Vancouver, British Columbia, Canada
| | - Leanne A Grieves
- Department of Biology, University of Western Ontario, London, Ontario, Canada
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Jane M Reid
- Centre for Biodiversity Dynamics, Institut for Biologi, NTNU, Trondheim, Norway
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Ryan R Germain
- Center for Macroecology, Evolution and Climate, GLOBE Institute, University of Copenhagen, Kobenhavn, Denmark
| | - Savo Lazic
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Sabrina S Taylor
- School of Renewable Natural Resources, Louisiana State University and AgCenter, Baton Rouge, Louisiana, USA
| | | | - Peter Arcese
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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4
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Taylor CH, Friberg IM, Jackson JA, Arriero E, Begon M, Wanelik KM, Paterson S, Bradley JE. Living with chronic infection: Persistent immunomodulation during avirulent haemoparasitic infection in a wild rodent. Mol Ecol 2023; 32:1197-1210. [PMID: 36478482 DOI: 10.1111/mec.16819] [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: 06/10/2022] [Revised: 10/07/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022]
Abstract
Apicomplexans are a protozoan phylum of obligate parasites which may be highly virulent during acute infections, but may also persist as chronic infections which appear to have little fitness cost. Babesia microti is an apicomplexan haemoparasite that, in immunocompromised individuals, can cause severe, potentially fatal disease. However, in its natural host, wild field voles (Microtus agrestis), it exhibits chronic infections that have no detectable impact on survival or female fecundity. How is damage minimized, and what is the impact on the host's immune state and health? We examine the differences in immune state (here represented by expression of immune-related genes in multiple tissues) associated with several common chronic infections in a population of wild field voles. While some infections show little impact on immune state, we find strong associations between immune state and B. microti. These include indications of clearance of infected erythrocytes (increased macrophage activity in the spleen) and activity likely associated with minimizing damage from the infection (anti-inflammatory and antioxidant activity in the blood). By analysing gene expression from the same individuals at multiple time points, we show that the observed changes are a response to infection, rather than a risk factor. Our results point towards continual investment to minimize the damage caused by the infection. Thus, we shed light on how wild animals can tolerate some chronic infections, but emphasize that this tolerance does not come without a cost.
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Affiliation(s)
| | - Ida M Friberg
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | - Joseph A Jackson
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | - Elena Arriero
- School of Life Sciences, University of Nottingham, Nottingham, UK.,Department of Biodiversity, Ecology and Evolution, Complutense University of Madrid, Madrid, Spain
| | - Mike Begon
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Klara M Wanelik
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK.,Department of Zoology, University of Oxford, Oxford, UK
| | - Steve Paterson
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
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5
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Liu W, McNeilly TN, Mitchell M, Burgess STG, Nisbet AJ, Matthews JB, Babayan SA. Vaccine-induced time- and age-dependent mucosal immunity to gastrointestinal parasite infection. NPJ Vaccines 2022; 7:78. [PMID: 35798788 PMCID: PMC9262902 DOI: 10.1038/s41541-022-00501-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 06/13/2022] [Indexed: 11/10/2022] Open
Abstract
Individuals vary broadly in their response to vaccination and subsequent challenge infection, with poor vaccine responders causing persistence of both infection and transmission in populations. Yet despite having substantial economic and societal impact, the immune mechanisms that underlie such variability, especially in infected tissues, remain poorly understood. Here, to characterise how antihelminthic immunity at the mucosal site of infection developed in vaccinated lambs, we inserted gastric cannulae into the abomasa of three-month- and six-month-old lambs and longitudinally analysed their local immune response during subsequent challenge infection. The vaccine induced broad changes in pre-challenge abomasal immune profiles and reduced parasite burden and egg output post-challenge, regardless of age. However, age affected how vaccinated lambs responded to infection across multiple immune pathways: adaptive immune pathways were typically age-dependent. Identification of age-dependent and age-independent protective immune pathways may help refine the formulation of vaccines, and indicate specificities of pathogen-specific immunity more generally.
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Affiliation(s)
- Wei Liu
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Tom N McNeilly
- The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK.
| | - Mairi Mitchell
- The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK
| | - Stewart T G Burgess
- The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK
| | - Alasdair J Nisbet
- The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK
| | - Jacqueline B Matthews
- The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK.,Roslin Technologies Limited, Roslin Innovation Centre, University of Edinburgh, Easter Bush, Scotland, EH25 9RG, UK
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK. .,The Moredun Research Institute, Pentlands Science Park, Scotland, EH26 0PZ, UK.
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6
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Bovenhuis H, Berghof TVL, Visker MHPW, Arts JAJ, Visscher J, van der Poel JJ, Parmentier HK. Divergent selection for natural antibodies in poultry in the presence of a major gene. Genet Sel Evol 2022; 54:24. [PMID: 35313798 PMCID: PMC8939063 DOI: 10.1186/s12711-022-00715-9] [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: 09/09/2021] [Accepted: 03/08/2022] [Indexed: 11/21/2022] Open
Abstract
Background Natural antibodies (NAb) are antibodies that are present in a healthy individual without requiring previous exposure to an exogenous antigen. Selection for high NAb levels might contribute to improved general disease resistance. Our aim was to analyse the genetic background of NAb based on a divergent selection experiment in poultry, and in particular the effect of a polymorphism in the TLR1A gene. Methods The study population consisted of a base population from a commercial pure-bred elite white leghorn layer line and seven generations of birds from a High and Low selection line. Birds were selected for total KLH-binding NAb titer (IgTotal). An enzyme-linked immunosorbent assay was performed to determine NAb titers in blood plasma for IgTotal and the antibody isotypes IgM and IgG. NAb titers were available for 10,878 birds. Genotypes for a polymorphism in TLR1A were determined for chickens in generations 5, 6 and 7. The data were analysed using mixed linear animal models. Results The heritability estimate for IgM was 0.30 and higher than that for IgG and IgTotal (0.12). Maternal environmental effects explained 2 to 3% of the phenotypic variation in NAb. Selection for IgTotal resulted in a genetic difference between the High and Low line of 2.4 titer points (5.1 genetic standard deviation) in generation 7. For IgM, the selection response was asymmetrical and higher in the Low than the High line. The frequency of the TLR1A C allele was 0.45 in the base population and 0.66 and 0.04 in generation 7 of the High and Low line, respectively. The TLR1A polymorphism had large and significant effects on IgTotal and IgM. Estimated genotypic effects suggest full dominance of the TLR1A C allele. Significant TLR1A by generation interactions were detected for IgM and IgTotal. Conclusions The effect of a polymorphism in the TLR1A gene on IgTotal and IgM NAb was confirmed. Furthermore, we provide experimental verification of changes in allele frequencies at a major gene with dominant gene action on a quantitative trait that is subjected to mass selection. TLR1A by generation interactions indicate sensitivity to environmental factors. Supplementary Information The online version contains supplementary material available at 10.1186/s12711-022-00715-9.
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Affiliation(s)
- Henk Bovenhuis
- Animal Breeding and Genomics Centre, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands.
| | - Tom V L Berghof
- Animal Breeding and Genomics Centre, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands.,Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands.,Reproductive Biotechnology, TUM School of Life Sciences, Technical University of Munich, Liesel-Beckmann-Strasse 1, 85354, Freising, Germany
| | - Marleen H P W Visker
- Animal Breeding and Genomics Centre, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Joop A J Arts
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Jeroen Visscher
- Hendrix Genetics Research Technology & Service B.V, P.O. Box 114, 5830 AC, Boxmeer, The Netherlands
| | - Jan J van der Poel
- Animal Breeding and Genomics Centre, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Henk K Parmentier
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
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7
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Benedict BM, Barboza PS. Adverse effects of Diptera flies on northern ungulates:
Rangifer
,
Alces
, and
Bison. Mamm Rev 2022. [DOI: 10.1111/mam.12287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bridgett M. Benedict
- Department of Ecology and Conservation Biology Texas A&M University 2258 TAMU, 534 John Kimbrough Blvd College Station TX77843USA
| | - Perry S. Barboza
- Department of Ecology and Conservation Biology Texas A&M University 2258 TAMU, 534 John Kimbrough Blvd College Station TX77843USA
- Department of Rangelands Wildlife and Fisheries Management Texas A&M University 2258 TAMU, 534 John Kimbrough Blvd College Station TX77843USA
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8
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Huang W, Dicks KL, Ballingall KT, Johnston SE, Sparks AM, Watt K, Pilkington JG, Pemberton JM. Associations between MHC class II variation and phenotypic traits in a free-living sheep population. Mol Ecol 2021; 31:902-915. [PMID: 34748666 DOI: 10.1111/mec.16265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 10/22/2021] [Accepted: 11/03/2021] [Indexed: 01/03/2023]
Abstract
Pathogen-mediated selection (PMS) is thought to maintain the high level of allelic diversity observed in the major histocompatibility complex (MHC) class II genes. A comprehensive way to demonstrate contemporary selection is to examine associations between MHC variation and individual fitness. As individual fitness is hard to measure, many studies examine associations between MHC variation and phenotypic traits, including direct or indirect measures of adaptive immunity thought to contribute to fitness. Here, we tested associations between MHC class II variation and five phenotypic traits measured in free-living sheep captured in August: weight, strongyle faecal egg count, and plasma IgA, IgE and IgG immunoglobulin titres against the gastrointestinal nematode parasite Teladorsagia circumcincta. We found no association between MHC class II variation and weight or strongyle faecal egg count. We did, however, find associations between MHC class II variation and immunoglobulin levels which varied with isotype, age and sex. Our results suggest associations between MHC and phenotypic traits are more likely to be found for traits more closely associated with pathogen defence than integrative traits such as bodyweight and highlight the association between MHC variation and antibodies in wild populations.
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Affiliation(s)
- Wei Huang
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Kara L Dicks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Alexandra M Sparks
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,School of Biology, University of Leeds, Leeds, UK
| | - Kathryn Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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9
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Behringer V, Müller-Klein N, Strube C, Schülke O, Heistermann M, Ostner J. Responsiveness of fecal immunoglobulin A to HPA-axis activation limits its use for mucosal immunity assessment. Am J Primatol 2021; 83:e23329. [PMID: 34554596 DOI: 10.1002/ajp.23329] [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: 06/04/2021] [Revised: 08/30/2021] [Accepted: 09/04/2021] [Indexed: 11/11/2022]
Abstract
The assessment of mucosal immunity as a component of animal health is an important aspect for the understanding of variation in host immunity, and its tradeoff against other life-history traits. We investigated immunoglobulin A (IgA), the major type of antibody associated with mucosal immunity, in relation to changes in parasitic burden following anthelminthic treatment in noninvasively collected fecal samples in a semi-free ranging group of Barbary macaques (Macaca sylvanus). We measured IgA in 340 fecal samples of fourteen females and nine males. As IgA has been found to be responsive to stressors, we also related fecal IgA (fIgA) levels to fecal glucocorticoid metabolites (fGCM) measured in the same samples as part of a previous study. We found a high variability within and between individual fIgA levels over time. Running generalized additive mixed models, we found that fIgA levels were higher in males than in females, but did not change in response to the anthelmintic treatment and the resulting reduction in worm burden. Instead, fIgA level changes were significantly correlated to changes in fGCM levels. Our findings indicate that due to the strong responsiveness of fIgA to HPA-axis activity, the measurement of fIgA may have certain limitations with respect to reflecting gastrointestinal parasitic burden. Moreover, the responsiveness of fIgA to stressors interferes with the interpretation of IgA levels in fecal samples as a measure of mucosal immunity, at least in our study population of the Barbary macaques.
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Affiliation(s)
- Verena Behringer
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Nadine Müller-Klein
- Institute for Evolutionary Ecology and Conservation Genomics, Ulm University, Ulm, Germany.,Research Group Social Evolution in Primates, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Oliver Schülke
- Research Group Social Evolution in Primates, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,Department of Behavioral Ecology, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany.,Leibniz ScienceCampus Primate Cognition, Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Julia Ostner
- Research Group Social Evolution in Primates, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,Department of Behavioral Ecology, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany.,Leibniz ScienceCampus Primate Cognition, Göttingen, Germany
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10
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Gauzere J, Walling CA, Pick JL, Watt K, Jack P, Morris A, Morris S, Pemberton JM. The role of maternally transferred antibodies in maternal performance in red deer. Ecol Lett 2021; 24:2065-2076. [PMID: 34245475 DOI: 10.1111/ele.13834] [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: 02/15/2021] [Revised: 03/25/2021] [Accepted: 06/04/2021] [Indexed: 11/28/2022]
Abstract
Maternal effects are ubiquitous. Yet, the pathways through which maternal effects occur in wild mammals remain largely unknown. We hypothesise that maternal immune transfer is a key mechanism by which mothers can affect their offspring fitness, and that individual variation in maternally derived antibodies mainly depends on a mother's characteristics and the environmental conditions she experiences. To test this, we assayed six colostrum-derived antibodies in the plasma of 1447 neonates in a wild red deer population. Neonatal antibody levels were mainly affected by maternal genes, environmental variation and costs of prior reproductive investment. We found consistent heterogeneity in maternal performance across traits, with mothers producing the heaviest calves also having calves with more antibodies. Unexpectedly, antibody levels were not associated with calf survival. We provide a unique example of how evolutionary theory on maternal effects can be used to gain insight into the causes of maternal effects in wild populations.
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Affiliation(s)
- Julie Gauzere
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Craig A Walling
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Joel L Pick
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Kathryn Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Penny Jack
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Alison Morris
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Sean Morris
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
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11
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Ferreira SCM, Veiga MM, Hofer H, East ML, Czirják GÁ. Noninvasively measured immune responses reflect current parasite infections in a wild carnivore and are linked to longevity. Ecol Evol 2021; 11:7685-7699. [PMID: 34188844 PMCID: PMC8216923 DOI: 10.1002/ece3.7602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 01/03/2023] Open
Abstract
Host immune defenses are important components of host-parasite interactions that affect the outcome of infection and may have fitness consequences for hosts when increased allocation of resources to immune responses undermines other essential life processes. Research on host-parasite interactions in large free-ranging wild mammals is currently hampered by a lack of verified noninvasive assays. We successfully adapted existing assays to measure innate and adaptive immune responses produced by the gastrointestinal mucosa in spotted hyena (Crocuta crocuta) feces, including enzyme-linked immunosorbent assays (ELISAs), to quantify fecal immunoglobulins (total IgA, total IgG) and total fecal O-linked oligosaccharides (mucin). We investigated the effect of infection load by an energetically costly hookworm (Ancylostoma), parasite richness, host age, sex, year of sampling, and clan membership on immune responses and asked whether high investment in immune responses during early life affects longevity in individually known spotted hyenas in the Serengeti National Park, Tanzania. Fecal concentrations of IgA, IgG, and mucin increased with Ancylostoma egg load and were higher in juveniles than in adults. Females had higher mucin concentrations than males. Juvenile females had higher IgG concentrations than juvenile males, whereas adult females had lower IgG concentrations than adult males. High IgA concentrations during the first year of life were linked to reduced longevity after controlling for age at sampling and Ancylostoma egg load. Our study demonstrates that the use of noninvasive methods can increase knowledge on the complex relationship between gastrointestinal parasites and host local immune responses in wild large mammals and reveal fitness-relevant effects of these responses.
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Affiliation(s)
- Susana C. M. Ferreira
- Department of Ecological DynamicsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
- Present address:
Division of Computational Systems BiologyCentre for Microbiology and Environmental Systems ScienceViennaAustria
| | - Miguel M. Veiga
- Department of Ecological DynamicsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
| | - Heribert Hofer
- Department of Ecological DynamicsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
- Department of Veterinary MedicineFreie Universität BerlinBerlinGermany
- Department of Biology, Chemistry and PharmacyFreie Universität BerlinBerlinGermany
| | - Marion L. East
- Department of Ecological DynamicsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
| | - Gábor Á. Czirják
- Department of Wildlife DiseasesLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
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12
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Ohmer MEB, Costantini D, Czirják GÁ, Downs CJ, Ferguson LV, Flies A, Franklin CE, Kayigwe AN, Knutie S, Richards-Zawacki CL, Cramp RL. Applied ecoimmunology: using immunological tools to improve conservation efforts in a changing world. CONSERVATION PHYSIOLOGY 2021; 9:coab074. [PMID: 34512994 PMCID: PMC8422949 DOI: 10.1093/conphys/coab074] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/27/2021] [Accepted: 08/09/2021] [Indexed: 05/11/2023]
Abstract
Ecoimmunology is a rapidly developing field that explores how the environment shapes immune function, which in turn influences host-parasite relationships and disease outcomes. Host immune defence is a key fitness determinant because it underlies the capacity of animals to resist or tolerate potential infections. Importantly, immune function can be suppressed, depressed, reconfigured or stimulated by exposure to rapidly changing environmental drivers like temperature, pollutants and food availability. Thus, hosts may experience trade-offs resulting from altered investment in immune function under environmental stressors. As such, approaches in ecoimmunology can provide powerful tools to assist in the conservation of wildlife. Here, we provide case studies that explore the diverse ways that ecoimmunology can inform and advance conservation efforts, from understanding how Galapagos finches will fare with introduced parasites, to using methods from human oncology to design vaccines against a transmissible cancer in Tasmanian devils. In addition, we discuss the future of ecoimmunology and present 10 questions that can help guide this emerging field to better inform conservation decisions and biodiversity protection. From better linking changes in immune function to disease outcomes under different environmental conditions, to understanding how individual variation contributes to disease dynamics in wild populations, there is immense potential for ecoimmunology to inform the conservation of imperilled hosts in the face of new and re-emerging pathogens, in addition to improving the detection and management of emerging potential zoonoses.
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Affiliation(s)
- Michel E B Ohmer
- Living Earth Collaborative, Washington University in St. Louis, MO 63130, USA
| | - David Costantini
- Unité Physiologie Moléculaire et Adaptation (PhyMA), Muséum National d’Histoire Naturelle, CNRS, 57 Rue Cuvier, CP32, 75005, Paris, France
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Cynthia J Downs
- Department of Environmental Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Laura V Ferguson
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andy Flies
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
| | - Ahab N Kayigwe
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Sarah Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06268, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268, USA
| | | | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Queensland 4072, Australia.
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13
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Roast MJ, Aranzamendi NH, Fan M, Teunissen N, Hall MD, Peters A. Fitness outcomes in relation to individual variation in constitutive innate immune function. Proc Biol Sci 2020; 287:20201997. [PMID: 33143586 DOI: 10.1098/rspb.2020.1997] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Although crucial for host survival when facing persistent parasite pressure, costly immune functions will inevitably compete for resources with other energetically expensive traits such as reproduction. Optimizing, but not necessarily maximizing, immune function might therefore provide net benefit to overall host fitness. Evidence for associations between fitness and immune function is relatively rare, limiting our potential to understand ultimate fitness costs of immune investment. Here, we assess how measures of constitutive immune function (haptoglobin, natural antibodies, complement activity) relate to subsequent fitness outcomes (survival, reproductive success, dominance acquisition) in a wild passerine (Malurus coronatus). Surprisingly, survival probability was not positively linearly predicted by any immune index. Instead, both low and high values of complement activity (quadratic effect) were associated with higher survival, suggesting that different immune investment strategies might reflect a dynamic disease environment. Positive linear relationships between immune indices and reproductive success suggest that individual heterogeneity overrides potential resource reallocation trade-offs within individuals. Controlling for body condition (size-adjusted body mass) and chronic stress (heterophil-lymphocyte ratio) did not alter our findings in a sample subset with available data. Overall, our results suggest that constitutive immune components have limited net costs for fitness and that variation in immune maintenance relates to individual differences more closely.
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Affiliation(s)
- Michael J Roast
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | | | - Marie Fan
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Niki Teunissen
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Matthew D Hall
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| | - Anne Peters
- School of Biological Sciences, Monash University, Victoria 3800, Australia
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14
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Reyneveld GIJ, Savelkoul HFJ, Parmentier HK. Current Understanding of Natural Antibodies and Exploring the Possibilities of Modulation Using Veterinary Models. A Review. Front Immunol 2020; 11:2139. [PMID: 33013904 PMCID: PMC7511776 DOI: 10.3389/fimmu.2020.02139] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/06/2020] [Indexed: 12/20/2022] Open
Abstract
Natural antibodies (NAb) are defined as germline encoded immunoglobulins found in individuals without (known) prior antigenic experience. NAb bind exogenous (e.g., bacterial) and self-components and have been found in every vertebrate species tested. NAb likely act as a first-line immune defense against infections. A large part of NAb, so called natural autoantibodies (NAAb) bind to and clear (self) neo-epitopes, apoptotic, and necrotic cells. Such self-binding antibodies cannot, however, be considered as pathogenic autoantibodies in the classical sense. IgM and IgG NAb and NAAb and their implications in health and disease are relatively well-described in humans and mice. NAb are present in veterinary (and wildlife) species, but their relation with diseases and disorders in veterinary species are much less known. Also, there is little known of IgA NAb. IgA is the most abundant immunoglobulin with essential pro-inflammatory and homeostatic properties urging for more research on the importance of IgA NAb. Since NAb in humans were indicated to fulfill important functions in health and disease, their role in health of veterinary species should be investigated more often. Furthermore, it is unknown whether levels of NAb-isotypes and/or idiotypes can and should be modulated. Veterinary species as models of choice fill in a niche between mice and (non-human) primates, and the study of NAb in veterinary species may provide valuable new insights that will likely improve health management. Below, examples of the involvement of NAb in several diseases in mostly humans are shown. Possibilities of intravenous immunoglobulin administration, targeted immunotherapy, immunization, diet, and genetic modulation are discussed, all of which could be well-studied using animal models. Arguments are given why veterinary immunology should obtain inspiration from human studies and why human immunology would benefit from veterinary models. Within the One Health concept, findings from veterinary (and wildlife) studies can be related to human studies and vice versa so that both fields will mutually benefit. This will lead to a better understanding of NAb: their origin, activation mechanisms, and their implications in health and disease, and will lead to novel health management strategies for both human and veterinary species.
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Affiliation(s)
- G. IJsbrand Reyneveld
- Faculty of Science, VU University, Amsterdam, Netherlands
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, Netherlands
| | - Huub F. J. Savelkoul
- Cell Biology and Immunology Group, Department of Animal Sciences, Wageningen University, Wageningen, Netherlands
| | - Henk K. Parmentier
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen University, Wageningen, Netherlands
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15
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Tombak KJ, Budischak SA, Hauck S, Martinez LA, Rubenstein DI. The non-invasive measurement of faecal immunoglobulin in African equids. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2020; 12:105-112. [PMID: 32528845 PMCID: PMC7283094 DOI: 10.1016/j.ijppaw.2020.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/08/2020] [Accepted: 05/09/2020] [Indexed: 12/16/2022]
Abstract
Eco-immunological research is encumbered by a lack of basic research in a wild context and by the availability of few non-invasive tools to measure the internal state of wild animals. The recent development of an enzyme-linked immunosorbent assay for measuring immunoglobulins in faecal samples from Soay sheep prompted us to optimize such an assay to measure immunoglobulin A (IgA: an antibody associated with parasitic nematode fecundity) in faecal samples from equids. We measured total IgA in domestic donkeys, wild plains zebras, and wild Grevy's zebras sharing the same landscape in central Kenya over two field seasons. Attempts to measure anti-nematode IgA more specifically, using a homogenized extract from a mixture of excreted nematodes, failed to clear background. However, we found that total IgA positively correlated with strongyle nematode faecal egg counts (FECs) in donkeys sampled during the wetter field season - a time when the donkeys were in good condition. Further, this relationship appeared among donkeys with high body condition but not among those with low body condition. Time lags of 1–4 days introduced between IgA and FEC measurements in repeatedly sampled donkeys did not yield correlations, suggesting that IgA and FEC roughly tracked one another without much delay in the wet field season. Such a direct IgA-FEC relationship did not appear for zebras in either the wet or dry field season, possibly due to higher interindividual variation in body condition among the free-roaming zebras than in the donkeys. However, Grevy's zebras had higher overall levels of IgA than either plains zebras or donkeys, potentially associated with their reportedly lower FECs at the population level. Our results suggest that equids may mount an IgA response to nematode egg production when the host is in good condition and that equid species may differ in baseline levels of mucosal IgA. We optimized an immunosorbent assay to non-invasively measure total IgA in faeces from equids. IgA positively correlated with nematode faecal egg count (FEC) in donkeys in good body condition. IgA and FEC were not correlated in a dry year for donkeys or in any year for wild plains and Grevy's zebras. IgA may relate to FECs at the population level only when body condition is uniformly good. IgA was higher in Grevy's than plains zebras or donkeys, suggesting differences in immune strategy.
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Affiliation(s)
- Kaia J Tombak
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
| | - Sarah A Budischak
- Keck Science Department of Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, United States
| | - Stephanie Hauck
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
| | - Lindsay A Martinez
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
| | - Daniel I Rubenstein
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
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16
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Froy H, Sparks AM, Watt K, Sinclair R, Bach F, Pilkington JG, Pemberton JM, McNeilly TN, Nussey DH. Senescence in immunity against helminth parasites predicts adult mortality in a wild mammal. Science 2020; 365:1296-1298. [PMID: 31604239 DOI: 10.1126/science.aaw5822] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 07/30/2019] [Indexed: 12/14/2022]
Abstract
Our understanding of the deterioration in immune function in old age-immunosenescence-derives principally from studies of modern human populations and laboratory animals. The generality and significance of this process for systems experiencing complex, natural infections and environmental challenges are unknown. Here, we show that late-life declines in an important immune marker of resistance to helminth parasites in wild Soay sheep predict overwinter mortality. We found senescence in circulating antibody levels against a highly prevalent nematode worm, which was associated with reduced adult survival probability, independent of changes in body weight. These findings establish a role for immunosenescence in the ecology and evolution of natural populations.
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Affiliation(s)
- H Froy
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK. .,Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - A M Sparks
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.,School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - K Watt
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - R Sinclair
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - F Bach
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, UK
| | - J G Pilkington
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - J M Pemberton
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - T N McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
| | - D H Nussey
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
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17
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Bruijning M, Metcalf CJE, Jongejans E, Ayroles JF. The Evolution of Variance Control. Trends Ecol Evol 2020; 35:22-33. [PMID: 31519463 PMCID: PMC7482585 DOI: 10.1016/j.tree.2019.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/08/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
Genetically identical individuals can be phenotypically variable, even in constant environmental conditions. The ubiquity of this phenomenon, known as 'intra-genotypic variability', is increasingly evident and the relevant mechanistic underpinnings are beginning to be understood. In parallel, theory has delineated a number of formal expectations for contexts in which such a feature would be adaptive. Here, we review empirical evidence across biological systems and theoretical expectations, including nonlinear averaging and bet hedging. We synthesize existing results to illustrate the dependence of selection outcomes both on trait characteristics, features of environmental variability, and species' demographic context. We conclude by discussing ways to bridge the gap between empirical evidence of intra-genotypic variability, studies demonstrating its genetic component, and evidence that it is adaptive.
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Affiliation(s)
- Marjolein Bruijning
- Department of Animal Ecology and Physiology, Radboud University, 6500, GL, Nijmegen, The Netherlands; Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA
| | - C Jessica E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA
| | - Eelke Jongejans
- Department of Animal Ecology and Physiology, Radboud University, 6500, GL, Nijmegen, The Netherlands
| | - Julien F Ayroles
- Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA.
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18
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Sparks AM, Watt K, Sinclair R, Pilkington JG, Pemberton JM, McNeilly TN, Nussey DH, Johnston SE. The genetic architecture of helminth-specific immune responses in a wild population of Soay sheep (Ovis aries). PLoS Genet 2019; 15:e1008461. [PMID: 31697674 PMCID: PMC6863570 DOI: 10.1371/journal.pgen.1008461] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 11/19/2019] [Accepted: 10/04/2019] [Indexed: 12/22/2022] Open
Abstract
Much of our knowledge of the drivers of immune variation, and how these responses vary over time, comes from humans, domesticated livestock or laboratory organisms. While the genetic basis of variation in immune responses have been investigated in these systems, there is a poor understanding of how genetic variation influences immunity in natural, untreated populations living in complex environments. Here, we examine the genetic architecture of variation in immune traits in the Soay sheep of St Kilda, an unmanaged population of sheep infected with strongyle gastrointestinal nematodes. We assayed IgA, IgE and IgG antibodies against the prevalent nematode Teladorsagia circumcincta in the blood plasma of > 3,000 sheep collected over 26 years. Antibody levels were significantly heritable (h2 = 0.21 to 0.57) and highly stable over an individual’s lifespan. IgA levels were strongly associated with a region on chromosome 24 explaining 21.1% and 24.5% of heritable variation in lambs and adults, respectively. This region was adjacent to two candidate loci, Class II Major Histocompatibility Complex Transactivator (CIITA) and C-Type Lectin Domain Containing 16A (CLEC16A). Lamb IgA levels were also associated with the immunoglobulin heavy constant loci (IGH) complex, and adult IgE levels and lamb IgA and IgG levels were associated with the major histocompatibility complex (MHC). This study provides evidence of high heritability of a complex immunological trait under natural conditions and provides the first evidence from a genome-wide study that large effect genes located outside the MHC region exist for immune traits in the wild. Understanding how immune responses vary in natural populations can give an insight into how infection affects the ability of hosts and parasites to survive and reproduce, and how this drives evolutionary and ecological dynamics. Yet, very little is known about how immune responses vary over an individual’s lifetime and how genes contribute to this variation under natural conditions. Our study investigates the genetic architecture of variation in three antibody types, IgA, IgE and IgG in a wild population of Soay sheep on the St Kilda archipelago in North-West Scotland. Using data collected over 26 years, we show that antibody levels have a heritable basis in lambs and adults and are stable over an individual’s lifetime. We also identify several genomic regions with large effects on immune responses. Our study offers the first insights into the genetic control of immunity in a wild population, which is essential to understand how immune profiles vary in challenging natural conditions and how natural selection maintains genetic variation in complex immune traits.
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Affiliation(s)
- Alexandra M. Sparks
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Biological Sciences, School of Biology, University of Leeds, Leeds, United Kingdom
- * E-mail:
| | - Kathryn Watt
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Rona Sinclair
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jill G. Pilkington
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Josephine M. Pemberton
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Tom N. McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Midlothian, United Kingdom
| | - Daniel H. Nussey
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Susan E. Johnston
- Institutes of Evolutionary Biology and Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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19
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Seguel M, Beechler BR, Coon CC, Snyder PW, Spaan JM, Jolles AE, Ezenwa VO. Immune stability predicts tuberculosis infection risk in a wild mammal. Proc Biol Sci 2019; 286:20191401. [PMID: 31575363 DOI: 10.1098/rspb.2019.1401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Immunity is one of the most variable phenotypic traits in animals; however, some individuals may show less fluctuation in immune traits, resulting in stable patterns of immune variation over time. It is currently unknown whether immune variation has consequences for infectious disease risk. In this study, we identified moderately stable immune traits in wild African buffalo and asked whether the stability of these traits affected bovine tuberculosis (TB) infection risk. We found that adaptive immune traits such as the level of interferon-γ (IFN-γ) released after white blood cell stimulation, the number of circulating lymphocytes and the level of antibodies against bovine adenovirus-3 were moderately repeatable (i.e. stable) over time, whereas parameters related to innate immunity either had low repeatability (circulating eosinophil numbers) or were not repeatable (e.g. neutrophil numbers, plasma bacteria killing capacity). Intriguingly, individuals with more repeatable IFN-γ and lymphocyte levels were at a significantly higher risk of acquiring TB infection. In stark contrast, average IFN-γ and lymphocyte levels were poor predictors of TB risk, indicating that immune variability rather than absolute response level better captured variation in disease susceptibility. This work highlights the important and under-appreciated role of immune variability as a predictor of infection risk.
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Affiliation(s)
- Mauricio Seguel
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Brianna R Beechler
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Courtney C Coon
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa.,Felidae Conservation Fund, Mill Valley, CA, USA
| | - Paul W Snyder
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Johannie M Spaan
- College of Osteopathic Medicine of the Pacific Northwest, Western University of Health Sciences, Lebanon, OR, USA
| | - Anna E Jolles
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA.,Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Vanessa O Ezenwa
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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20
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Hayward AD, Pilkington JG, Wilson K, McNeilly TN, Watt KA. Reproductive effort influences intra‐seasonal variation in parasite‐specific antibody responses in wild Soay sheep. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adam D. Hayward
- Moredun Research Institute Penicuik UK
- Department of Biological and Environmental Sciences University of Stirling Stirling UK
| | | | - Kenneth Wilson
- Lancaster Environment Centre Lancaster University Lancaster UK
| | | | - Kathryn A. Watt
- Institute of Evolutionary Biology Ashworth Laboratories Edinburgh UK
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21
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Woods GM, Fox S, Flies AS, Tovar CD, Jones M, Hamede R, Pemberton D, Lyons AB, Bettiol SS. Two Decades of the Impact of Tasmanian Devil Facial Tumor Disease. Integr Comp Biol 2019; 58:1043-1054. [PMID: 30252058 DOI: 10.1093/icb/icy118] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Tasmanian devil, a marsupial carnivore, has been restricted to the island state of Tasmania since its extinction on the Australian mainland about 3000 years ago. In the past two decades, this species has experienced severe population decline due to the emergence of devil facial tumor disease (DFTD), a transmissible cancer. During these 20 years, scientists have puzzled over the immunological and evolutionary responses by the Tasmanian devil to this transmissible cancer. Targeted strategies in population management and disease control have been developed as well as comparative processes to identify variation in tumor and host genetics. A multi-disciplinary approach with multi-institutional teams has produced considerable advances over the last decade. This has led to a greater understanding of the molecular pathogenesis and genomic classification of this cancer. New and promising developments in the Tasmanian devil's story include evidence that most immunized, and some wild devils, can produce an immune response to DFTD. Furthermore, epidemiology combined with genomic studies suggest a rapid evolution to the disease and that DFTD will become an endemic disease. Since 1998 there have been more than 350 publications, distributed over 37 Web of Science categories. A unique endemic island species has become an international curiosity that is in the spotlight of integrative and comparative biology research.
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Affiliation(s)
- Gregory M Woods
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - Samantha Fox
- Save the Tasmanian Devil Program, DPIPWE, GPO Box 44, Hobart, Tasmania 7001, Australia.,Toledo Zoo, 2605 Broadway, Toledo, OH 43609, USA
| | - Andrew S Flies
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - Cesar D Tovar
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7005, Australia.,School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - Menna Jones
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - David Pemberton
- Save the Tasmanian Devil Program, DPIPWE, GPO Box 44, Hobart, Tasmania 7001, Australia
| | - A Bruce Lyons
- School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - Silvana S Bettiol
- School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania 7005, Australia
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22
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Clerc M, Babayan SA, Fenton A, Pedersen AB. Age affects antibody levels and anthelmintic treatment efficacy in a wild rodent. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 8:240-247. [PMID: 30923672 PMCID: PMC6423487 DOI: 10.1016/j.ijppaw.2019.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/25/2019] [Accepted: 03/09/2019] [Indexed: 12/22/2022]
Abstract
The role of the host immune system in determining parasite burdens and mediating within-host parasite interactions has traditionally been studied in highly controlled laboratory conditions. This does, however, not reflect the diversity of individuals living in nature, which is often characterised by significant variation in host demography, such as host age, sex, and infection history. Whilst studies using wild hosts and parasites are beginning to give insights into the complex relationships between immunity, parasites and host demography, the cause-and-effect relationships often remain unknown due to a lack of high resolution, longitudinal data. We investigated the infection dynamics of two interacting gastrointestinal parasites of wild wood mice (Apodemus sylvaticus), the nematode Heligmosomoides polygyrus and the coccidian Eimeria hungaryensis, in order to assess the links between infection, coinfection, and the immunological dynamics of two antibodies (IgG1 and IgA). In an anthelmintic treatment experiment, mice were given a single oral dose of an anthelmintic treatment, or control dose, and then subsequently followed longitudinally over a period of 7–15 days to measure parasite burdens and antibody levels. Anthelmintic treatment successfully reduced burdens of H. polygyrus, but had no significant impact on E. hungaryensis. Treatment efficacy was driven by host age, with adult mice showing stronger reductions in burdens compared to younger mice. We also found that the relationship between H. polygyrus-specific IgG1 and nematode burden changed from positive in young mice to negative in adult mice. Our results highlight that a key host demographic factor like age could account for large parts of the variation in nematode burden and nematode-specific antibody levels observed in a naturally infected host population, possibly due to different immune responses in young vs. old animals. Given the variable success in community-wide de-worming programmes in animals and humans, accounting for the age-structure of a population could increase overall efficacy. Anthelmintic treatment reveals strong force of infection for H. polygyrus in wild wood mice. Anthelmintic treatment is more successful in younger compared to older mice. Relationship between IgG1 and H. polygyrus burden reverts with host age.
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Affiliation(s)
- Melanie Clerc
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK.,MRC Centre for Inflammation Research, Queen´s Medical Research Institute, University of Edinburgh UK, EH16 4TJ, UK
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andy Fenton
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Amy B Pedersen
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
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Sylvester TT, Parsons SDC, van Helden PD, Miller MA, Loxton AG. A pilot study evaluating the utility of commercially available antibodies for flow cytometric analysis of Panthera species lymphocytes. BMC Vet Res 2018; 14:410. [PMID: 30567560 PMCID: PMC6299994 DOI: 10.1186/s12917-018-1717-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 11/26/2018] [Indexed: 11/25/2022] Open
Abstract
Background The immune response against tuberculosis in lions is still poorly defined and our understanding is hampered by the lack of lion specific reagents. The process for producing antibodies against a specific antigen is laborious and not available to many research laboratories. As the search for antibody cross-reactivity is an important strategy for immunological studies in veterinary medicine, we have investigated the use of commercially available antibodies to characterize T cell subsets in African lions (Panthera leo). Results Commercially available antibodies were screened and investigated the influence of two different sample processing methods, as well as the effect of time delay on cell surface marker expression on lion lymphocytes. Using commercially available antibodies, we were able to identify CD4+, CD5+, CD8+, CD14+, CD25+, CD44+ and CD45+ T lymphocytes in samples obtained by density gradient centrifugation as well as red cell lysis of lion whole blood. Two distinct lymphocyte populations, which differed in size and phenotype, were observed in the samples processed by density gradient centrifugation. Conclusion Commercially available antibodies are able to differentiate between T lymphocyte subsets including immune effector cells in African lion whole blood, and possibly give insight into unique specie phenotypes. Electronic supplementary material The online version of this article (10.1186/s12917-018-1717-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tashnica Taime Sylvester
- NRF/DST Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
| | - Sven David Charles Parsons
- NRF/DST Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Paul David van Helden
- NRF/DST Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Michele Ann Miller
- NRF/DST Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Andre Gareth Loxton
- NRF/DST Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Sparks AM, Watt K, Sinclair R, Pilkington JG, Pemberton JM, Johnston SE, McNeilly TN, Nussey DH. Natural Selection on Antihelminth Antibodies in a Wild Mammal Population. Am Nat 2018; 192:745-760. [PMID: 30444657 DOI: 10.1086/700115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
An effective immune response is expected to confer fitness benefits through improved resistance to parasites but also incur energetic costs that negatively impact fitness-related traits, such as reproduction. The fitness costs and benefits of an immune response are likely to depend on host age, sex, and levels of parasite exposure. Few studies have examined the full extent to which patterns of natural selection on immune phenotypes vary across demographic groups and environments in the wild. Here, we assessed natural selection on plasma levels of three functionally distinct isotypes (IgA, IgE, and IgG) of antibodies against a prevalent nematode parasite measured in a wild Soay sheep population over 26 years. We found little support for environment-dependent selection or reproductive costs. However, antibody levels were negatively associated with parasite egg counts and positively associated with subsequent survival, albeit in a highly age- and isotype-dependent manner. Raised levels of antiparasite IgA best predicted reduced egg counts, but this did not predict survival in lambs. In adults increased antiparasite IgG predicted reduced egg counts, and in adult females IgG levels also positively predicted overwinter survival. Our results highlight the potential importance of age- and sex-dependent selection on immune phenotypes in nature and show that patterns of selection can vary even among functionally related immune markers.
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Abolins S, Lazarou L, Weldon L, Hughes L, King EC, Drescher P, Pocock MJO, Hafalla JCR, Riley EM, Viney M. The ecology of immune state in a wild mammal, Mus musculus domesticus. PLoS Biol 2018; 16:e2003538. [PMID: 29652925 PMCID: PMC5919074 DOI: 10.1371/journal.pbio.2003538] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 04/25/2018] [Accepted: 03/09/2018] [Indexed: 01/08/2023] Open
Abstract
The immune state of wild animals is largely unknown. Knowing this and what affects it is important in understanding how infection and disease affects wild animals. The immune state of wild animals is also important in understanding the biology of their pathogens, which is directly relevant to explaining pathogen spillover among species, including to humans. The paucity of knowledge about wild animals' immune state is in stark contrast to our exquisitely detailed understanding of the immunobiology of laboratory animals. Making an immune response is costly, and many factors (such as age, sex, infection status, and body condition) have individually been shown to constrain or promote immune responses. But, whether or not these factors affect immune responses and immune state in wild animals, their relative importance, and how they interact (or do not) are unknown. Here, we have investigated the immune ecology of wild house mice-the same species as the laboratory mouse-as an example of a wild mammal, characterising their adaptive humoral, adaptive cellular, and innate immune state. Firstly, we show how immune variation is structured among mouse populations, finding that there can be extensive immune discordance among neighbouring populations. Secondly, we identify the principal factors that underlie the immunological differences among mice, showing that body condition promotes and age constrains individuals' immune state, while factors such as microparasite infection and season are comparatively unimportant. By applying a multifactorial analysis to an immune system-wide analysis, our results bring a new and unified understanding of the immunobiology of a wild mammal.
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Affiliation(s)
- Stephen Abolins
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Luke Lazarou
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Laura Weldon
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Louise Hughes
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Elizabeth C. King
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Paul Drescher
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | | | - Julius C. R. Hafalla
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Eleanor M. Riley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Mark Viney
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail:
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27
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Bayersdorf R, Fruscalzo A, Catania F. Linking autoimmunity to the origin of the adaptive immune system. EVOLUTION MEDICINE AND PUBLIC HEALTH 2018; 2018:2-12. [PMID: 29423226 PMCID: PMC5793817 DOI: 10.1093/emph/eoy001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In jawed vertebrates, the adaptive immune system (AIS) cooperates with the innate immune system (IIS) to protect hosts from infections. Although targeting non-self-components, the AIS also generates self-reactive antibodies which, when inadequately counter-selected, can give rise to autoimmune diseases (ADs). ADs are on the rise in western countries. Why haven’t ADs been eliminated during the evolution of a ∼500 million-year old system? And why have they become more frequent in recent decades? Self-recognition is an attribute of the phylogenetically more ancient IIS and empirical data compellingly show that some self-reactive antibodies, which are classifiable as elements of the IIS rather then the AIS, may protect from (rather than cause) ADs. Here, we propose that the IIS’s self-recognition system originally fathered the AIS and, as a consequence of this relationship, its activity is dampened in hygienic environments. Rather than a mere breakdown or failure of the mechanisms of self-tolerance, ADs might thus arise from architectural constraints.
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Affiliation(s)
- Robert Bayersdorf
- Institute for Genome Stability in Aging and Disease, Medical Faculty, University of Cologne, 50931 Cologne, Germany.,Institute for Evolution and Biodiversity, University of Münster, 48149 Münster, Germany
| | - Arrigo Fruscalzo
- Clinic of Obstetrics and Gynecology, St Franziskus Hospital, 59227 Ahlen, Germany.,Department of Obstetrics and Gynecology, University Hospital of Münster, 48149 Münster, Germany
| | - Francesco Catania
- Institute for Evolution and Biodiversity, University of Münster, 48149 Münster, Germany
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28
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Monteith KL, Long RA, Stephenson TR, Bleich VC, Bowyer RT, Lasharr TN. Horn size and nutrition in mountain sheep: Can ewe handle the truth? J Wildl Manage 2017. [DOI: 10.1002/jwmg.21338] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kevin L. Monteith
- Haub School of Environment and Natural Resources, Wyoming Cooperative Fish and Wildlife Research UnitDepartment of Zoology and Physiology, University of Wyoming 804 East Fremont St. Laramie WY 82072 USA
| | - Ryan A. Long
- Department of Fish and Wildlife SciencesUniversity of Idaho 875 Perimeter Dr., MS 1142 Moscow ID 83844 USA
| | - Thomas R. Stephenson
- Sierra Nevada Bighorn Sheep Recovery ProgramCalifornia Department of Fish and Wildlife 787 North Main Street, Suite 220 Bishop CA 93514 USA
| | - Vernon C. Bleich
- Department of Natural Resources and Environmental ScienceUniversity of Nevada Reno Mail Stop 186, 1664 North Virginia Street Reno NV 89557 USA
| | - R. Terry Bowyer
- Institute of Arctic BiologyUniversity of Alaska Fairbanks Box 757000 Fairbanks AK 99775 USA
| | - Tayler N. Lasharr
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and PhysiologyUniversity of Wyoming Dept. 3166, 1000 E. University Ave Laramie WY 82071 USA
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29
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Physiological proteins in resource-limited herbivores experiencing a population die-off. Naturwissenschaften 2017; 104:68. [PMID: 28761976 PMCID: PMC5537310 DOI: 10.1007/s00114-017-1490-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 07/13/2017] [Accepted: 07/15/2017] [Indexed: 11/01/2022]
Abstract
Nutrient availability is predicted to interact with herbivore population densities. Competition for low quality food at high density may reduce summer food intake, and in turn winter survival. Conversely, low population density may favor physiological recovery through better access to better quality spring forage. Here, we take advantage of the long-term study of the Soay sheep population of St. Kilda (Scotland) to measure plasma protein markers and immunity in two consecutive summers with contrasting population densities. We show that, following a winter die-off resulting in a shift to low population density, albumin and total proteins increased, but only in adult sheep. The effect was not solely attributable to selective disappearance of malnourished sheep. Similarly, the concentration of antibodies was higher following the die-off, potentially indicating recovery of immune function. Overall, our results are consistent with the physiological recovery of surviving individuals after a harsh winter.
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30
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Caudron Q, Garnier R, Pilkington JG, Watt KA, Hansen C, Grenfell BT, Aboellail T, Graham AL. Robust extraction of quantitative structural information from high-variance histological images of livers from necropsied Soay sheep. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170111. [PMID: 28791138 PMCID: PMC5541533 DOI: 10.1098/rsos.170111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
Quantitative information is essential to the empirical analysis of biological systems. In many such systems, spatial relations between anatomical structures is of interest, making imaging a valuable data acquisition tool. However, image data can be difficult to analyse quantitatively. Many image processing algorithms are highly sensitive to variations in the image, limiting their current application to fields where sample and image quality may be very high. Here, we develop robust image processing algorithms for extracting structural information from a dataset of high-variance histological images of inflamed liver tissue obtained during necropsies of wild Soay sheep. We demonstrate that features of the data can be measured in a fully automated manner, providing quantitative information which can be readily used in statistical analysis. We show that these methods provide measures that correlate well with a manual, expert operator-led analysis of the same images, that they provide advantages in terms of sampling a wider range of information and that information can be extracted far more quickly than in manual analysis.
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Affiliation(s)
- Q. Caudron
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - R. Garnier
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - J. G. Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - K. A. Watt
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - C. Hansen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - B. T. Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - T. Aboellail
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA
| | - A. L. Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
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31
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Lobato E, Doutrelant C, Melo M, Reis S, Covas R. Insularity effects on bird immune parameters: A comparison between island and mainland populations in West Africa. Ecol Evol 2017; 7:3645-3656. [PMID: 28616162 PMCID: PMC5468148 DOI: 10.1002/ece3.2788] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 11/30/2016] [Accepted: 12/21/2016] [Indexed: 01/19/2023] Open
Abstract
Oceanic islands share several environmental characteristics that have been shown to drive convergent evolutionary changes in island organisms. One change that is often assumed but has seldom been examined is the evolution of weaker immune systems in island species. The reduction in species richness on islands is expected to lead to a reduced parasite pressure and, given that immune function is costly, island animals should show a reduced immune response. However, alternative hypotheses exist; for example, the slower pace of life on islands could favor the reorganization of the immune system components (innate vs. acquired immunity) on islands. Thus far, few island species have been studied and no general patterns have emerged. Here, we compared two immune parameters of birds from São Tomé and Príncipe islands to those of their close relatives at similar latitudes on the mainland (Gabon, West Africa). On islands, the acquired humoral component (total immunoglobulins) was lower for most species, whereas no clear pattern was detected for the innate component (haptoglobin levels). These different responses did not seem to arise from a reorganization of the two immune components, as both total immunoglobulins and haptoglobin levels were positively associated. This work adds to the few empirical studies conducted so far which suggest that changes in immune parameters in response to insularity are not as straightforward as initially thought.
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Affiliation(s)
- Elisa Lobato
- CIBIO/InBio Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,CEFE Centre d'Ecologie Fonctionnelle et Evolutive CNRS UMR 5175 Montpellier Cedex 5 France
| | - Claire Doutrelant
- CEFE Centre d'Ecologie Fonctionnelle et Evolutive CNRS UMR 5175 Montpellier Cedex 5 France
| | - Martim Melo
- CIBIO/InBio Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,Percy FitzPatrick Institute of African Ornithology DST-NRF Center of Excellence University of Cape Town Rondebosch South Africa
| | - Sandra Reis
- CIBIO/InBio Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal
| | - Rita Covas
- CIBIO/InBio Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,Percy FitzPatrick Institute of African Ornithology DST-NRF Center of Excellence University of Cape Town Rondebosch South Africa.,Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal
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32
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A candidate gene approach to study nematode resistance traits in naturally infected sheep. Vet Parasitol 2017; 243:71-74. [PMID: 28807314 PMCID: PMC5567408 DOI: 10.1016/j.vetpar.2017.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/27/2017] [Accepted: 06/09/2017] [Indexed: 01/31/2023]
Abstract
SNPs within genes associated with the development of nematode resistance were sequenced. The SNPs were segregating in two unrelated, domestic and feral, sheep breeds. More samples are required to determine significant associations between SNPs and traits.
Sheep naturally acquire a degree of resistant immunity to parasitic worm infection through repeated exposure. However, the immune response and clinical outcome vary greatly between animals. Genetic polymorphisms in genes integral to differential T helper cell polarization may contribute to variation in host response and disease outcome. A total of twelve single nucleotide polymorphisms (SNPs) were sequenced in IL23R, RORC2 and TBX21 from genomic DNA of Scottish Blackface lambs. Of the twelve SNPs, six were non-synonymous (missense), four were within the 3′ UTRs and two were intronic. The association between nine of these SNPs and the traits of body weight, faecal egg count (FEC) and relative T. circumcincta L3-specific IgA antibody levels was assessed in a population of domestic Scottish Blackface ewe lambs and a population of free-living Soay ewe lambs both naturally infected with a mixture of nematodes. There were no significant associations identified between any of the SNPs and phenotypes recorded in either of the populations after adjustment for multiple testing (Bonferroni corrected P value ≤ 0.002). In the Blackface lambs, there was a nominally significant association (P = 0.007) between IL23R p.V324M and weight at 20 weeks. This association may be worthy of further investigation in a larger sample of sheep.
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Zhao Y, Li M, Sun Y, Wu W, Kou G, Guo L, Xing D, Wu Y, Li D, Zhao B. Life-history dependent relationships between body condition and immunity, between immunity indices in male Eurasian tree sparrows. Comp Biochem Physiol A Mol Integr Physiol 2017; 210:7-13. [PMID: 28499964 DOI: 10.1016/j.cbpa.2017.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/04/2017] [Accepted: 05/04/2017] [Indexed: 01/30/2023]
Abstract
In free-living animals, recent evidence indicates that innate, and acquired, immunity varies with annual variation in the demand for, and availability of, food resources. However, little is known about how animals adjust the relationships between immunity and body condition, and between innate and acquired immunity to optimize survival over winter and reproductive success during the breeding stage. Here, we measured indices of body condition (size-corrected mass [SCM], and hematocrit [Hct]), constitutive innate immunity (plasma total complement hemolysis activity [CH50]) and acquired immunity (plasma immunoglobulin A [IgA]), plus heterophil/lymphocyte (H/L) ratios, in male Eurasian tree sparrows (Passer montanus) during the wintering and the breeding stages. We found that birds during the wintering stage had higher IgA levels than those from the breeding stage. Two indices of body condition were both negatively correlated with plasma CH50 activities, and positively with IgA levels in wintering birds, but this was not the case in the breeding birds. However, there was no correlation between CH50 activities and IgA levels in both stages. These results suggest that the relationships between body condition and immunity can vary across life-history stage, and there are no correlations between innate and acquired immunity independent of life-history stage, in male Eurasian tree sparrows. Therefore, body condition indices predict immunological state, especially during the non-breeding stage, which can be useful indicators of individual immunocompetences for understanding the variations in innate and acquired immunity in free-living animals.
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Affiliation(s)
- Yuliang Zhao
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Mo Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Yanfeng Sun
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China; Ocean College, Agricultural University of Hebei, Qinhuangdao 066003, People's Republic of China
| | - Wei Wu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Guanqun Kou
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Lingling Guo
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Danning Xing
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Yuefeng Wu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China
| | - Dongming Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China.
| | - Baohua Zhao
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, People's Republic of China.
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34
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Festa-Bianchet M, Douhard M, Gaillard JM, Pelletier F. Successes and challenges of long-term field studies of marked ungulates. J Mammal 2017. [DOI: 10.1093/jmammal/gyw227] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Garnier R, Cheung CK, Watt KA, Pilkington JG, Pemberton JM, Graham AL. Joint associations of blood plasma proteins with overwinter survival of a large mammal. Ecol Lett 2017; 20:175-183. [DOI: 10.1111/ele.12719] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 10/31/2016] [Accepted: 11/17/2016] [Indexed: 02/02/2023]
Affiliation(s)
- Romain Garnier
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton NJ USA
| | - Christopher K. Cheung
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton NJ USA
| | - Kathryn A. Watt
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Edinburgh UK
| | - Jill G. Pilkington
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Edinburgh UK
| | - Josephine M. Pemberton
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Edinburgh UK
| | - Andrea L. Graham
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton NJ USA
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36
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Watson RL, McNeilly TN, Watt KA, Pemberton JM, Pilkington JG, Waterfall M, Hopper PRT, Cooney D, Zamoyska R, Nussey DH. Cellular and humoral immunity in a wild mammal: Variation with age & sex and association with overwinter survival. Ecol Evol 2016; 6:8695-8705. [PMID: 28035261 PMCID: PMC5192870 DOI: 10.1002/ece3.2584] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/31/2022] Open
Abstract
Immune defenses are expected to be crucial for survival under the considerable parasite pressures experienced by wild animals. However, our understanding of the association between immunity and fitness in nature remains limited due to both the complexity of the vertebrate immune system and the often‐limited availability of immune reagents in nonmodel organisms. Here, we use methods and reagents developed by veterinary researchers for domestic ungulates on blood samples collected from a wild Soay sheep population, to evaluate an unusually broad panel of immune parameters. Our evaluation included different innate and acquired immune cell types as well as nematode parasite‐specific antibodies of different isotypes. We test how these markers correlate with one another, how they vary with age‐group and sex, and, crucially, whether they predict overwinter survival either within or among demographic groups. We found anticipated patterns of variation in markers with age, associated with immune development, and once these age trends were accounted for, correlations among our 11 immune markers were generally weak. We found that females had higher proportions of naïve T cells and gamma–delta T cells than males, independent of age, while our other markers did not differ between sexes. Only one of our 11 markers predicted overwinter survival: sheep with higher plasma levels of anti‐nematode IgG antibodies were significantly more likely to survive the subsequent high mortality winter, independent of age, sex, or weight. This supports a previous finding from this study system using a different set of samples and shows that circulating antibody levels against ecologically relevant parasites in natural systems represent an important parameter of immune function and may be under strong natural selection. Our data provide rare insights into patterns of variation among age‐ and sex groups in different T‐cell subsets and antibody levels in the wild, and suggest that certain types of immune response—notably those likely to be repeatable within individuals and linked to resistance to ecologically relevant parasites—may be most informative for research into the links between immunity and fitness under natural conditions.
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Affiliation(s)
- Rebecca L Watson
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | | | - Kathryn A Watt
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Josephine M Pemberton
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Jill G Pilkington
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Martin Waterfall
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Phoebe R T Hopper
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Daniel Cooney
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Rose Zamoyska
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
| | - Daniel H Nussey
- School of Biological Sciences Institutes of Evolutionary Biology & Immunology and Infection Research University of Edinburgh Edinburgh UK
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37
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Gibson AK, Jokela J, Lively CM. Fine-Scale Spatial Covariation between Infection Prevalence and Susceptibility in a Natural Population. Am Nat 2016; 188:1-14. [PMID: 27322117 DOI: 10.1086/686767] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The prevalence of infection varies dramatically on a fine spatial scale. Many evolutionary hypotheses are founded on the assumption that this variation is due to host genetics, such that sites with a high frequency of alleles conferring susceptibility are associated with higher infection prevalence. This assumption is largely untested and may be compromised at finer spatial scales where gene flow between sites is high. We put this assumption to the test in a natural snail-trematode interaction in which host susceptibility is known to have a strong genetic basis. A decade of field sampling revealed substantial spatial variation in infection prevalence between 13 sites around a small lake. Laboratory assays replicated over 3 years demonstrate striking variation in host susceptibility among sites in spite of high levels of gene flow between sites. We find that mean susceptibility can explain more than one-third of the observed variation in mean infection prevalence among sites. We estimate that variation in susceptibility and exposure together can explain the majority of variation in prevalence. Overall, our findings in this natural host-parasite system argue that spatial variation in infection prevalence covaries strongly with variation in the distribution of genetically based susceptibility, even at a fine spatial scale.
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38
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Kwok ABC, Wardle GM, Greenville AC, Dickman CR. Long‐term patterns of invertebrate abundance and relationships to environmental factors in arid Australia. AUSTRAL ECOL 2016. [DOI: 10.1111/aec.12334] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Alan B. C. Kwok
- Desert Ecology Research Group School of Biological Sciences University of Sydney Sydney New South Wales
- Long Term Ecological Research Network Terrestrial Ecosystem Research Network Brisbane Queensland Australia
| | - Glenda M. Wardle
- Desert Ecology Research Group School of Biological Sciences University of Sydney Sydney New South Wales
- Long Term Ecological Research Network Terrestrial Ecosystem Research Network Brisbane Queensland Australia
| | - Aaron C. Greenville
- Desert Ecology Research Group School of Biological Sciences University of Sydney Sydney New South Wales
- Long Term Ecological Research Network Terrestrial Ecosystem Research Network Brisbane Queensland Australia
| | - Chris R. Dickman
- Desert Ecology Research Group School of Biological Sciences University of Sydney Sydney New South Wales
- Long Term Ecological Research Network Terrestrial Ecosystem Research Network Brisbane Queensland Australia
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39
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Exposure to viral and bacterial pathogens among Soay sheep (Ovis aries) of the St Kilda archipelago. Epidemiol Infect 2016; 144:1879-88. [PMID: 26829883 PMCID: PMC4890341 DOI: 10.1017/s0950268816000017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure to Leptospira spp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor to Chlamydia abortus. Some sheep tested positive for antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen-host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.
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40
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Vitamin D status predicts reproductive fitness in a wild sheep population. Sci Rep 2016; 6:18986. [PMID: 26757805 PMCID: PMC4725927 DOI: 10.1038/srep18986] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/02/2015] [Indexed: 01/01/2023] Open
Abstract
Vitamin D deficiency has been associated with the development of many human diseases, and with poor reproductive performance in laboratory rodents. We currently have no idea how natural selection directly acts on variation in vitamin D metabolism due to a total lack of studies in wild animals. Here, we measured serum 25 hydroxyvitamin D (25(OH)D) concentrations in female Soay sheep that were part of a long-term field study on St Kilda. We found that total 25(OH)D was strongly influenced by age, and that light coloured sheep had higher 25(OH)D3 (but not 25(OH)D2) concentrations than dark sheep. The coat colour polymorphism in Soay sheep is controlled by a single locus, suggesting vitamin D status is heritable in this population. We also observed a very strong relationship between total 25(OH)D concentrations in summer and a ewe’s fecundity the following spring. This resulted in a positive association between total 25(OH)D and the number of lambs produced that survived their first year of life, an important component of female reproductive fitness. Our study provides the first insight into naturally-occurring variation in vitamin D metabolites, and offers the first evidence that vitamin D status is both heritable and under natural selection in the wild.
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41
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Robertson S, Bradley JE, MacColl ADC. Measuring the immune system of the three-spined stickleback - investigating natural variation by quantifying immune expression in the laboratory and the wild. Mol Ecol Resour 2015; 16:701-13. [PMID: 26646722 PMCID: PMC4991546 DOI: 10.1111/1755-0998.12497] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/23/2015] [Accepted: 11/26/2015] [Indexed: 11/28/2022]
Abstract
Current understanding of the immune system comes primarily from laboratory-based studies. There has been substantial interest in examining how it functions in the wild, but studies have been limited by a lack of appropriate assays and study species. The three-spined stickleback (Gasterosteus aculeatus L.) provides an ideal system in which to advance the study of wild immunology, but requires the development of suitable immune assays. We demonstrate that meaningful variation in the immune response of stickleback can be measured using real-time PCR to quantify the expression of eight genes, representing the innate response and Th1-, Th2- and Treg-type adaptive responses. Assays are validated by comparing the immune expression profiles of wild and laboratory-raised stickleback, and by examining variation across populations on North Uist, Scotland. We also compare the immune response potential of laboratory-raised individuals from two Icelandic populations by stimulating cells in culture. Immune profiles of wild fish differed from laboratory-raised fish from the same parental population, with immune expression patterns in the wild converging relative to those in the laboratory. Innate measures differed between wild populations, whilst the adaptive response was associated with variation in age, relative size of fish, reproductive status and S. solidus infection levels. Laboratory-raised individuals from different populations showed markedly different innate immune response potential. The ability to combine studies in the laboratory and in the wild underlines the potential of this toolkit to advance our understanding of the ecological and evolutionary relevance of immune system variation in a natural setting.
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Affiliation(s)
- Shaun Robertson
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Janette E Bradley
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Andrew D C MacColl
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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42
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Watt KA, Nussey DH, Maclellan R, Pilkington JG, McNeilly TN. Fecal antibody levels as a noninvasive method for measuring immunity to gastrointestinal nematodes in ecological studies. Ecol Evol 2015; 6:56-67. [PMID: 26811774 PMCID: PMC4716500 DOI: 10.1002/ece3.1858] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/21/2022] Open
Abstract
Among‐individual variation in antibody‐associated immunity to gastrointestinal nematode parasites (GIN) is known be associated with life‐history traits and vital rates in wild vertebrate systems. To date, measurement of levels of antibodies against GIN antigens in natural populations has exclusively been based on invasive blood sampling techniques. Previous work in laboratory rodents and ruminant livestock suggests that antibody measures from feces may provide a viable noninvasive approach. We measured total and anti‐GIN antibodies of different isotypes (immunoglobulin (Ig) G, IgA and IgE) from paired samples of plasma and feces from free‐living Soay sheep of different ages and sexes. We tested the correlations among these measures as well as their associations with body mass and Strongyle nematode fecal egg counts (FEC). Significant positive correlations were present among plasma and fecal anti‐GIN antibody levels for IgG and IgA. Generally, correlations between total antibody levels in plasma and feces were weaker and not significant. No significant relationships were found between any antibody measures and body mass; however, fecal anti‐GIN antibody levels were significantly negatively correlated with FEC. Our data clearly demonstrate the feasibility of measuring anti‐GIN antibodies from fecal samples collected in natural populations. Although associations of fecal antibody levels with their plasma counterparts and FEC were relatively weak, the presence of significant correlations in the predicted direction in a relatively small and heterogeneous sample suggests fecal antibody measures could be a useful, noninvasive addition to current eco‐immunological studies.
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Affiliation(s)
- Kathryn A Watt
- Institutes of Evolutionary Biology and Immunology and Infection Research School of Biological Sciences University of Edinburgh West Mains Road Edinburgh UK
| | - Daniel H Nussey
- Institutes of Evolutionary Biology and Immunology and Infection Research School of Biological Sciences University of Edinburgh West Mains Road Edinburgh UK
| | - Rachel Maclellan
- Institutes of Evolutionary Biology and Immunology and Infection Research School of Biological Sciences University of Edinburgh West Mains Road Edinburgh UK
| | - Jill G Pilkington
- Institutes of Evolutionary Biology and Immunology and Infection Research School of Biological Sciences University of Edinburgh West Mains Road Edinburgh UK
| | - Tom N McNeilly
- Moredun Research Institute Pentlands Science Park Bush Loan Midlothian UK
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43
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Metcalf CJE, Graham AL, Martinez-Bakker M, Childs DZ. Opportunities and challenges of Integral Projection Models for modelling host-parasite dynamics. J Anim Ecol 2015; 85:343-55. [PMID: 26620440 PMCID: PMC4991293 DOI: 10.1111/1365-2656.12456] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/29/2015] [Indexed: 11/28/2022]
Abstract
Epidemiological dynamics are shaped by and may in turn shape host demography. These feedbacks can result in hard to predict patterns of disease incidence. Mathematical models that integrate infection and demography are consequently a key tool for informing expectations for disease burden and identifying effective measures for control. A major challenge is capturing the details of infection within individuals and quantifying their downstream impacts to understand population‐scale outcomes. For example, parasite loads and antibody titres may vary over the course of an infection and contribute to differences in transmission at the scale of the population. To date, to capture these subtleties, models have mostly relied on complex mechanistic frameworks, discrete categorization and/or agent‐based approaches. Integral Projection Models (IPMs) allow variance in individual trajectories of quantitative traits and their population‐level outcomes to be captured in ways that directly reflect statistical models of trait–fate relationships. Given increasing data availability, and advances in modelling, there is considerable potential for extending this framework to traits of relevance for infectious disease dynamics. Here, we provide an overview of host and parasite natural history contexts where IPMs could strengthen inference of population dynamics, with examples of host species ranging from mice to sheep to humans, and parasites ranging from viruses to worms. We discuss models of both parasite and host traits, provide two case studies and conclude by reviewing potential for both ecological and evolutionary research.
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Affiliation(s)
- C Jessica E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.,Office of Population Research, The Woodrow Wilson School, Princeton University, Princeton, NJ, USA
| | - Andrea L Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | | | - Dylan Z Childs
- Department of Animal and Plant Sciences, Sheffield University, Sheffield, UK
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44
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Abstract
Gastrointestinal nematodes represent important sources of economic losses in farmed ruminants, and the increasing frequency of anthelmintic resistance requires an increased ability to explore alternative strategies. Theoretical approaches at the crossroads of immunology and epidemiology are valuable tools in that context. In the case of Teladorsagia circumcincta in sheep, the immunological mechanisms important for resistance are increasingly well-characterized. However, despite the existence of a wide range of theoretical models, there is no framework integrating the characteristic features of this immune response into a tractable phenomenological model. Here, we propose to bridge that gap by developing a flexible modelling framework that allows for variability in nematode larval intake which can be used to track the variations in worm burdens. We parameterize this model using data from trickle infection of sheep and show that using simple immunological assumptions, our model can capture the dynamics of both adult worm burdens and nematode fecal egg counts. In addition, our analysis reveals interesting dose-dependent effects on the immune response. Finally, we discuss potential developments of this model and highlight how an improved cross-talk between empiricists and theoreticians would facilitate important advances in the study of infectious diseases.
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45
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Downs CJ, Stewart KM, Dick BL. Investment in constitutive immune function by North American elk experimentally maintained at two different population densities. PLoS One 2015; 10:e0125586. [PMID: 25992627 PMCID: PMC4439091 DOI: 10.1371/journal.pone.0125586] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 03/25/2015] [Indexed: 02/03/2023] Open
Abstract
Natural selection favors individuals that respond with effective and appropriate immune responses to macro or microparasites. Animals living in populations close to ecological carrying capacity experience increased intraspecific competition, and as a result are often in poor nutritional condition. Nutritional condition, in turn, affects the amount of endogenous resources that are available for investment in immune function. Our objective was to understand the relationship between immune function and density dependence mediated by trade-offs between immune function, nutritional condition, and reproduction. To determine how immune function relates to density-dependent processes, we quantified bacteria killing ability, hemolytic-complement activity, and nutritional condition of North American elk (Cervus elaphus) from populations maintained at experimentally high- and low-population densities. When compared with elk from the low-density population, those from the high-density population had higher bacteria killing ability and hemolytic-complement activity despite their lower nutritional condition. Similarly, when compared with adults, yearlings had higher bacteria killing ability, higher hemolytic-complement activity, and lower nutritional condition. Pregnancy status and lactational status did not change either measure of constitutive immunity. Density-dependent processes affected both nutritional condition and investment in constitutive immune function. Although the mechanism for how density affects immunity is ambiguous, we hypothesize two possibilities: (i) individuals in higher population densities and in poorer nutritional condition invested more into constitutive immune defenses, or (ii) had higher parasite loads causing higher induced immune responses. Those explanations are not mutually exclusive, and might be synergistic, but overall our results provide stronger support for the hypothesis that animals in poorer nutritional condition invest more in constitutive immune defenses then animals in better nutritional condition. This intriguing hypothesis should be investigated further within the larger framework of the cost and benefit structure of immune responses.
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Affiliation(s)
- Cynthia J. Downs
- Department of Natural Resources and Environmental Sciences, University of Nevada, Reno, Nevada, United States of America
| | - Kelley M. Stewart
- Department of Natural Resources and Environmental Sciences, University of Nevada, Reno, Nevada, United States of America
| | - Brian L. Dick
- Pacific Northwest Research Station, United States Forest Service, La Grande, Oregon, United States of America
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46
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Jolles AE, Beechler BR, Dolan BP. Beyond mice and men: environmental change, immunity and infections in wild ungulates. Parasite Immunol 2015; 37:255-66. [PMID: 25354672 PMCID: PMC4414670 DOI: 10.1111/pim.12153] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023]
Abstract
In the face of rapid environmental change, anticipating shifts in microparasite and macroparasite dynamics, including emergence events, is an enormous challenge. We argue that immunological studies in natural populations are pivotal to meeting this challenge: many components of environmental change--shifts in biotic assemblages, altered climate patterns and reduced environmental predictability--may affect host immunity. We suggest that wild ungulates can serve as model systems aiding the discovery of immunological mechanisms that link environmental change with parasite transmission dynamics. Our review of eco-immunological studies in wild ungulates reveals progress in understanding how co-infections affect immunity and parasite transmission and how environmental and genetic factors interact to shape immunity. Changes in bioavailability of micronutrients have been linked to immunity and health in wild ungulates. Although physiological stress in response to environmental change has been assessed, downstream effects on immunity have not been studied. Moreover, the taxonomic range of ungulates studied is limited to bovids (bighorn sheep, Soay sheep, chamois, musk oxen, bison, African buffalo) and a few cervids (red deer, black-tailed deer). We discuss areas where future studies in ungulates could lead to significant contributions in understanding the patterns of immunity and infection in natural populations and across species.
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Affiliation(s)
- Anna E. Jolles
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331
| | - Brianna R. Beechler
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331
| | - Brian P. Dolan
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331
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47
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Demas GE, Carlton ED. Ecoimmunology for psychoneuroimmunologists: Considering context in neuroendocrine-immune-behavior interactions. Brain Behav Immun 2015; 44:9-16. [PMID: 25218837 PMCID: PMC4275338 DOI: 10.1016/j.bbi.2014.09.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/26/2014] [Accepted: 09/01/2014] [Indexed: 02/06/2023] Open
Abstract
The study of immunity has become an important area of investigation for researchers in a wide range of areas outside the traditional discipline of immunology. For the last several decades, psychoneuroimmunology (PNI) has strived to identify key interactions among the nervous, endocrine and immune systems and behavior. More recently, the field of ecological immunology (ecoimmunology) has been established within the perspectives of ecology and evolutionary biology, sharing with PNI an appreciation of the environmental influences on immune function. The primary goal of ecoimmunology is to understand immune function within a broadly integrative, organismal context, typically from an ultimate, evolutionary perspective. To accomplish this ecoimmunology, like PNI, has become a broadly integrative field of investigation, combining diverse approaches from evolution and ecology to endocrinology and neurobiology. The disciplines of PNI and ecoimmunology, with their unique yet complementary perspectives and methodologies, have much to offer one another. Researchers in both fields, however, remain largely unaware of each other's findings despite attempts at integration. The goal of this review is to share with psychoneuroimmunologists and other mechanistically-oriented researchers some of the core concepts and principles, as well as relevant recent findings, within ecoimmunology with the hope that this information will prove relevant to their own research programs. More broadly, our goal is to attempt to integrate both the proximate and ultimate perspectives offered by PNI and ecoimmunology respectively into a common theoretical framework for understanding neuro-endocrine-immune interactions and behavior in a larger ecological, evolutionary context.
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Affiliation(s)
- Gregory E Demas
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Elizabeth D Carlton
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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Ramos R, Garnier R, González-Solís J, Boulinier T. Long antibody persistence and transgenerational transfer of immunity in a long-lived vertebrate. Am Nat 2014; 184:764-76. [PMID: 25438176 DOI: 10.1086/678400] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although little studied in natural populations, the persistence of immunoglobulins may dramatically affect the dynamics of immunity and the ecology and evolution of host-pathogen interactions involving vertebrate hosts. By means of a multiple-year vaccination design against Newcastle disease virus, we experimentally addressed whether levels of specific antibodies can persist over several years in females of a long-lived procellariiform seabird-Cory's shearwater-and whether maternal antibodies against that antigen could persist over a long period in offspring several years after the mother was exposed. We found that a single vaccination led to high levels of antibodies for several years and that the females transmitted antibodies to their offspring that persisted for several weeks after hatching even 5 years after a single vaccination. The temporal persistence of maternally transferred antibodies in nestlings was highly dependent on the level at hatching. A second vaccination boosted efficiently the level of antibodies in females and thus their transfer to offspring. Overall, these results stress the need to consider the temporal dynamics of immune responses if we are to understand the evolutionary ecology of host-parasite interactions and trade-offs between immunity and other life-history characteristics, in particular in long-lived species. They also have strong implications for conservation when vaccination may be used in natural populations facing disease threats.
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Affiliation(s)
- Raül Ramos
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS-Université Montpellier Unité Mixte de Recherche 5175, 1919 Route de Mende, 34293 Montpellier, France
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Bowers EK, Hodges CJ, Forsman AM, Vogel LA, Masters BS, Johnson BGP, Johnson LS, Thompson CF, Sakaluk SK. Neonatal body condition, immune responsiveness, and hematocrit predict longevity in a wild bird population. Ecology 2014; 95:3027-3034. [PMID: 25505800 PMCID: PMC4260523 DOI: 10.1890/14-0418.1] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Measures of body condition, immune function, and hematological health are widely used in ecological studies of vertebrate populations, predicated on the assumption that these traits are linked to fitness. However, compelling evidence that these traits actually predict long-term survival and reproductive success among individuals in the wild is lacking. Here, we show that body condition (i.e., size-adjusted body mass) and cutaneous immune responsiveness to phytohaemagglutinin (PHA) injection among neonates positively predict recruitment and subsequent longevity in a wild, migratory population of house wrens (Troglodytes aedon). However, neonates with intermediate hematocrit had the highest recruitment and longevity. Neonates with the highest PHA responsiveness and intermediate hematocrit prior to independence eventually produced the most offspring during their lifetime breeding on the study site. Importantly, the effects of PHA responsiveness and hematocrit were revealed while controlling for variation in body condition, sex, and environmental variation. Thus, our data demonstrate that body condition, cutaneous immune responsiveness, and hematocrit as a neonate are associated with individual fitness. Although hematocrit's effect is more complex than traditionally thought, our results suggest a previously underappreciated role for this trait in influencing survival in the wild.
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Affiliation(s)
- E. Keith Bowers
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Christine J. Hodges
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Anna M. Forsman
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Laura A. Vogel
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Brian S. Masters
- Department of Biological Sciences, Towson University, Towson, MD 21252 USA
| | | | - L. Scott Johnson
- Department of Biological Sciences, Towson University, Towson, MD 21252 USA
| | - Charles F. Thompson
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Scott K. Sakaluk
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA
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50
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Hayward AD, Garnier R, Watt KA, Pilkington JG, Grenfell BT, Matthews JB, Pemberton JM, Nussey DH, Graham AL. Heritable, Heterogeneous, and Costly Resistance of Sheep against Nematodes and Potential Feedbacks to Epidemiological Dynamics. Am Nat 2014; 184 Suppl 1:S58-76. [DOI: 10.1086/676929] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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