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Kaliappan A, Ramakrishnan S, Thomas P, Verma SK, Panwar K, Singh M, Dey S, Mohan Chellappa M. Polymorphism in the leucine-rich repeats of TLR7 in different breeds of chicken and in silico analysis of its effect on TLR7 structure and function. Gene 2024; 912:148373. [PMID: 38490513 DOI: 10.1016/j.gene.2024.148373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/02/2024] [Accepted: 03/12/2024] [Indexed: 03/17/2024]
Abstract
Chicken toll-like receptor 7 (chTLR7) is a viral sensing pattern recognition receptor and detects ssRNA. The ligand binding site comprises leucine-rich repeats (LRRs) located in the ectodomain of chTLR7. Hence, any polymorphism in the binding site would modify its functional interaction with the ligand, resulting in varied strength of immune response. This study first aimed to compare the single nucleotide polymorphisms (SNPs) associated with the ligand binding site of TLR7 in three indigenous chicken breeds namely Aseel, Kadaknath, Nicobari along with an exotic breed White Leghorn. Four synonymous SNPs (P123P, I171I, N339N and L421L) and four non-synonymous SNPs (I121V, S135T, F356S and S447G) were identified among various breeds. We employed in silico tools to screen the pathogenic nsSNPs and one nsSNP was identified as having potential impact on chTLR7 protein. Moreover, sequence and structure-based methods were used to determine the effect of nsSNPs on protein stability. It revealed I121V, F356S, and S447G as decreasing the stability while S135T increasing the stability of chTLR7. Additionally, docking analysis confirmed that I121V and F356S reduced the binding affinity of ligands (R-848 and polyU) to chTLR7 protein. The results suggest that the nsSNPs found in this study could alter the ligand binding of chTLR7 and modify the immune response between different breeds further contributing to disease susceptibility or resistance. Further, in vitro and in vivo studies are needed to analyze the effect of these SNPs on susceptibility or resistance against various viral diseases in poultry.
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Affiliation(s)
- Abinaya Kaliappan
- Immunology Section, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Saravanan Ramakrishnan
- Immunology Section, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India.
| | - Prasad Thomas
- Division of Bacteriology and Mycology, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Surya Kant Verma
- Immunology Section, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Khushboo Panwar
- Immunology Section, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Mithilesh Singh
- Immunology Section, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Sohini Dey
- Recombinant DNA Laboratory, Division of Veterinary Biotechnology, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
| | - Madhan Mohan Chellappa
- Recombinant DNA Laboratory, Division of Veterinary Biotechnology, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243 122, India
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2
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Melepat B, Li T, Vinkler M. Natural selection directing molecular evolution in vertebrate viral sensors. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 154:105147. [PMID: 38325501 DOI: 10.1016/j.dci.2024.105147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 12/30/2023] [Accepted: 02/03/2024] [Indexed: 02/09/2024]
Abstract
Diseases caused by pathogens contribute to molecular adaptations in host immunity. Variety of viral pathogens challenging animal immunity can drive positive selection diversifying receptors recognising the infections. However, whether distinct virus sensing systems differ across animals in their evolutionary modes remains unclear. Our review provides a comparative overview of natural selection shaping molecular evolution in vertebrate viral-binding pattern recognition receptors (PRRs). Despite prevailing negative selection arising from the functional constraints, multiple lines of evidence now suggest diversifying selection in the Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs) and oligoadenylate synthetases (OASs). In several cases, location of the positively selected sites in the ligand-binding regions suggests effects on viral detection although experimental support is lacking. Unfortunately, in most other PRR families including the AIM2-like receptor family, C-type lectin receptors (CLRs), and cyclic GMP-AMP synthetase studies characterising their molecular evolution are rare, preventing comparative insight. We indicate shared characteristics of the viral sensor evolution and highlight priorities for future research.
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Affiliation(s)
- Balraj Melepat
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 43, Prague, EU, Czech Republic
| | - Tao Li
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 43, Prague, EU, Czech Republic
| | - Michal Vinkler
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 43, Prague, EU, Czech Republic.
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3
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Su Q, Chen Y, He H. Molecular evolution of Toll-like receptors in rodents. Integr Zool 2024; 19:371-386. [PMID: 37403417 DOI: 10.1111/1749-4877.12746] [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] [Indexed: 07/06/2023]
Abstract
Toll-like receptors (TLRs), the key sensor molecules in vertebrates, trigger the innate immunity and prime the adaptive immune system. The TLR family of rodents, the largest order of mammals, typically contains 13 TLR genes. However, a clear picture of the evolution of the rodent TLR family has not yet emerged and the TLR evolutionary patterns are unclear in rodent clades. Here, we analyzed the natural variation and the evolutionary processes acting on the TLR family in rodents at both the interspecific and population levels. Our results showed that rodent TLRs were dominated by purifying selection, but a series of positively selected sites (PSSs) primarily located in the ligand-binding domain was also identified. The numbers of PSSs differed among TLRs, and nonviral-sensing TLRs had more PSSs than those in viral-sensing TLRs. Gene-conversion events were found between TLR1 and TLR6 in most rodent species. Population genetic analyses showed that TLR2, TLR8, and TLR12 were under positive selection in Rattus norvegicus and R. tanezumi, whereas positive selection also acted on TLR5 and TLR9 in the former species, as well as TLR1 and TLR7 in the latter species. Moreover, we found that the proportion of polymorphisms with potentially functional change was much lower in viral-sensing TLRs than in nonviral-sensing TLRs in both of these rat species. Our findings revealed the first thorough insight into the evolution of the rodent TLR genetic variability and provided important novel insights into the evolutionary history of TLRs over long and short timescales.
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Affiliation(s)
- Qianqian Su
- College of Forestry, Central South University of Forestry and Technology, Changsha, China
- National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yi Chen
- College of Forestry, Central South University of Forestry and Technology, Changsha, China
| | - Hongxuan He
- National Research Center for Wildlife-Borne Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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4
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Coupé S, Giantsis IA, Vázquez Luis M, Scarpa F, Foulquié M, Prévot J, Casu M, Lattos A, Michaelidis B, Sanna D, García‐March JR, Tena‐Medialdea J, Vicente N, Bunet R. The characterization of toll-like receptor repertoire in Pinna nobilis after mass mortality events suggests adaptive introgression. Ecol Evol 2023; 13:e10383. [PMID: 37546570 PMCID: PMC10401143 DOI: 10.1002/ece3.10383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 07/16/2023] [Accepted: 07/18/2023] [Indexed: 08/08/2023] Open
Abstract
The fan mussel Pinna nobilis is currently on the brink of extinction due to a multifactorial disease mainly caused to the highly pathogenic parasite Haplosporidium pinnae, meaning that the selection pressure outweighs the adaptive potential of the species. Hopefully, rare individuals have been observed somehow resistant to the parasite, stretching the need to identify the traits underlying this better fitness. Among the candidate to explore at first intention are fast-evolving immune genes, of which toll-like receptor (TLR). In this study, we examined the genetic diversity at 14 TLR loci across P. nobilis, Pinna rudis and P. nobilis × P. rudis hybrid genomes, collected at four physically distant regions, that were found to be either resistant or sensitive to the parasite H. pinnae. We report a high genetic diversity, mainly observed at cell surface TLRs compared with that of endosomal TLRs. However, the endosomal TLR-7 exhibited unexpected level of diversity and haplotype phylogeny. The lack of population structure, associated with a high genetic diversity and elevated dN/dS ratio, was interpreted as balancing selection, though both directional and purifying selection were detected. Interestingly, roughly 40% of the P. nobilis identified as resistant to H. pinnae were introgressed with P. rudis TLR. Specifically, they all carried a TLR-7 of P. rudis origin, whereas sensitive P. nobilis were not introgressed, at least at TLR loci. Small contributions of TLR-6 and TLR-4 single-nucleotide polymorphisms to the clustering of resistant and susceptible individuals could be detected, but their specific role in resistance remains highly speculative. This study provides new information on the diversity of TLR genes within the P. nobilis species after MME and additional insights into adaptation to H. pinnae that should contribute to the conservation of this Mediterranean endemic species.
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Affiliation(s)
- Stéphane Coupé
- Université de Toulon, Aix Marseille Univ, CNRS, IRD, MIOMarseilleFrance
| | | | - Maite Vázquez Luis
- Instituto Español de Oceanografía (IEO, CSIC), Centro Oceanográfico de BalearesPalma de MallorcaSpain
| | - Fabio Scarpa
- Department of Biomedical SciencesFabio Scarpa, Daria Sanna: University of SassariSassariItaly
| | - Mathieu Foulquié
- Université de Toulon, Aix Marseille Univ, CNRS, IRD, MIOMarseilleFrance
- Institut océanographique Paul RicardIle des Embiez, VarFrance
| | | | - Marco Casu
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Athanasios Lattos
- Faculty of Agricultural SciencesUniversity of Western MacedoniaKozaniGreece
| | - Basile Michaelidis
- Faculty of Agricultural SciencesUniversity of Western MacedoniaKozaniGreece
| | - Daria Sanna
- Department of Biomedical SciencesFabio Scarpa, Daria Sanna: University of SassariSassariItaly
| | - José Rafa García‐March
- IMEDMAR‐UCV, Institute of Environment and Marine Science ResearchUniversidad Católica de Valencia SVMCalpe, AlicanteSpain
| | - José Tena‐Medialdea
- IMEDMAR‐UCV, Institute of Environment and Marine Science ResearchUniversidad Católica de Valencia SVMCalpe, AlicanteSpain
| | - Nardo Vicente
- Institut Méditerranéen de Biodiversité et Ecologie marine et continentale (IMBE), Aix‐Marseille Université, CNRS, IRD, Avignon UniversitéAvignonFrance
| | - Robert Bunet
- Institut océanographique Paul RicardIle des Embiez, VarFrance
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5
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Włodarczyk R, Těšický M, Vinkler M, Novotný M, Remisiewicz M, Janiszewski T, Minias P. Divergent evolution drives high diversity of toll-like receptors (TLRs) in passerine birds: Buntings and finches. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 144:104704. [PMID: 37019350 DOI: 10.1016/j.dci.2023.104704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/29/2023] [Accepted: 03/29/2023] [Indexed: 06/05/2023]
Abstract
Toll-like receptors (TLRs) form a key component of animal innate immunity, being responsible for recognition of conserved microbial structures. As such, TLRs may be subject to diversifying and balancing selection, which maintains allelic variation both within and between populations. However, most research on TLRs in non-model avian species is focused on bottlenecked populations with depleted genetic variation. Here, we assessed variation at the extracellular domains of three TLR genes (TLR1LA, TLR3, TLR4) across eleven species from two passerine families of buntings (Emberizidae) and finches (Fringillidae), all having large breeding population sizes (millions of individuals). We found extraordinary TLR polymorphism in our study taxa, with >100 alleles detected at TLR1LA and TLR4 across species and high haplotype diversity (>0.75) in several species. Despite recent species divergence, no nucleotide allelic variants were shared between species, suggesting rapid TLR evolution. Higher variation at TLR1LA and TLR4 than TLR3 was associated with a stronger signal of diversifying selection, as measured with nucleotide substitutions rates and the number of positively selected sites (PSS). Structural protein modelling of TLRs showed that some PSS detected within TLR1LA and TLR4 were previously recognized as functionally important sites or were located in their proximity, possibly affecting ligand recognition. Furthermore, we identified PSS responsible for major surface electrostatic charge clustering, which may indicate their adaptive importance. Our study provides compelling evidence for the divergent evolution of TLR genes in buntings and finches and indicates that high TLR variation may be adaptively maintained via diversifying selection acting on functional ligand binding sites.
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Affiliation(s)
- Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland.
| | - Martin Těšický
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 43, Prague, Czech Republic
| | - Michal Vinkler
- Charles University, Faculty of Science, Department of Zoology, Viničná 7, 128 43, Prague, Czech Republic
| | - Marian Novotný
- Charles University, Faculty of Science, Department of Cell Biology, Viničná 7, 128 43, Prague, Czech Republic
| | - Magdalena Remisiewicz
- Bird Migration Research Station, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
| | - Tomasz Janiszewski
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland
| | - Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland.
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6
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Vinkler M, Fiddaman SR, Těšický M, O'Connor EA, Savage AE, Lenz TL, Smith AL, Kaufman J, Bolnick DI, Davies CS, Dedić N, Flies AS, Samblás MMG, Henschen AE, Novák K, Palomar G, Raven N, Samaké K, Slade J, Veetil NK, Voukali E, Höglund J, Richardson DS, Westerdahl H. Understanding the evolution of immune genes in jawed vertebrates. J Evol Biol 2023; 36:847-873. [PMID: 37255207 PMCID: PMC10247546 DOI: 10.1111/jeb.14181] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 06/01/2023]
Abstract
Driven by co-evolution with pathogens, host immunity continuously adapts to optimize defence against pathogens within a given environment. Recent advances in genetics, genomics and transcriptomics have enabled a more detailed investigation into how immunogenetic variation shapes the diversity of immune responses seen across domestic and wild animal species. However, a deeper understanding of the diverse molecular mechanisms that shape immunity within and among species is still needed to gain insight into-and generate evolutionary hypotheses on-the ultimate drivers of immunological differences. Here, we discuss current advances in our understanding of molecular evolution underpinning jawed vertebrate immunity. First, we introduce the immunome concept, a framework for characterizing genes involved in immune defence from a comparative perspective, then we outline how immune genes of interest can be identified. Second, we focus on how different selection modes are observed acting across groups of immune genes and propose hypotheses to explain these differences. We then provide an overview of the approaches used so far to study the evolutionary heterogeneity of immune genes on macro and microevolutionary scales. Finally, we discuss some of the current evidence as to how specific pathogens affect the evolution of different groups of immune genes. This review results from the collective discussion on the current key challenges in evolutionary immunology conducted at the ESEB 2021 Online Satellite Symposium: Molecular evolution of the vertebrate immune system, from the lab to natural populations.
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Affiliation(s)
- Michal Vinkler
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | | | - Martin Těšický
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | | | - Anna E. Savage
- Department of BiologyUniversity of Central FloridaFloridaOrlandoUSA
| | - Tobias L. Lenz
- Research Unit for Evolutionary ImmunogenomicsDepartment of BiologyUniversity of HamburgHamburgGermany
| | | | - Jim Kaufman
- Institute for Immunology and Infection ResearchUniversity of EdinburghEdinburghUK
- Department of Veterinary MedicineUniversity of CambridgeCambridgeUK
| | - Daniel I. Bolnick
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | | | - Neira Dedić
- Department of Botany and ZoologyMasaryk UniversityBrnoCzech Republic
| | - Andrew S. Flies
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - M. Mercedes Gómez Samblás
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
- Department of ParasitologyUniversity of GranadaGranadaSpain
| | | | - Karel Novák
- Department of Genetics and BreedingInstitute of Animal SciencePragueUhříněvesCzech Republic
| | - Gemma Palomar
- Faculty of BiologyInstitute of Environmental SciencesJagiellonian UniversityKrakówPoland
| | - Nynke Raven
- Department of ScienceEngineering and Build EnvironmentDeakin UniversityVictoriaWaurn PondsAustralia
| | - Kalifa Samaké
- Department of Genetics and MicrobiologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Joel Slade
- Department of BiologyCalifornia State UniversityFresnoCaliforniaUSA
| | | | - Eleni Voukali
- Department of ZoologyFaculty of ScienceCharles UniversityPragueCzech Republic
| | - Jacob Höglund
- Department of Ecology and GeneticsUppsala UniversitetUppsalaSweden
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7
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Ducatelle R, Goossens E, Eeckhaut V, Van Immerseel F. Poultry gut health and beyond. ANIMAL NUTRITION 2023; 13:240-248. [PMID: 37168453 PMCID: PMC10164775 DOI: 10.1016/j.aninu.2023.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/15/2023] [Accepted: 03/21/2023] [Indexed: 04/07/2023]
Abstract
Intestinal health is critically important for the digestion and absorption of nutrients and thus is a key factor in determining performance. Intestinal health issues are very common in high performing poultry lines due to the high feed intake, which puts pressure on the physiology of the digestive system. Excess nutrients which are not digested and absorbed in the small intestine may trigger dysbiosis, i.e. a shift in the microbiota composition in the intestinal tract. Dysbiosis as well as other stressors elicit an inflammatory response and loss of integrity of the tight junctions between the epithelial cells, leading to gut leakage. In this paper, key factors determining intestinal health and the most important nutritional tools which are available to support intestinal health are reviewed.
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8
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Jain A, Mittal S, Tripathi LP, Nussinov R, Ahmad S. Host-pathogen protein-nucleic acid interactions: A comprehensive review. Comput Struct Biotechnol J 2022; 20:4415-4436. [PMID: 36051878 PMCID: PMC9420432 DOI: 10.1016/j.csbj.2022.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/01/2022] [Accepted: 08/01/2022] [Indexed: 12/02/2022] Open
Abstract
Recognition of pathogen-derived nucleic acids by host cells is an effective host strategy to detect pathogenic invasion and trigger immune responses. In the context of pathogen-specific pharmacology, there is a growing interest in mapping the interactions between pathogen-derived nucleic acids and host proteins. Insight into the principles of the structural and immunological mechanisms underlying such interactions and their roles in host defense is necessary to guide therapeutic intervention. Here, we discuss the newest advances in studies of molecular interactions involving pathogen nucleic acids and host factors, including their drug design, molecular structure and specific patterns. We observed that two groups of nucleic acid recognizing molecules, Toll-like receptors (TLRs) and the cytoplasmic retinoic acid-inducible gene (RIG)-I-like receptors (RLRs) form the backbone of host responses to pathogen nucleic acids, with additional support provided by absent in melanoma 2 (AIM2) and DNA-dependent activator of Interferons (IFNs)-regulatory factors (DAI) like cytosolic activity. We review the structural, immunological, and other biological aspects of these representative groups of molecules, especially in terms of their target specificity and affinity and challenges in leveraging host-pathogen protein-nucleic acid interactions (HP-PNI) in drug discovery.
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Affiliation(s)
- Anuja Jain
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Shikha Mittal
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, 173234, India
| | - Lokesh P. Tripathi
- National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan
- Riken Center for Integrative Medical Sciences, Tsurumi, Yokohama, Kanagawa, Japan
| | - Ruth Nussinov
- Computational Structural Biology Section, Basic Science Program, Frederick National, Laboratory for Cancer Research, Frederick, MD 21702, USA
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Israel
| | - Shandar Ahmad
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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Minias P, Vinkler M. Selection balancing at innate immune genes: adaptive polymorphism maintenance in Toll-like receptors. Mol Biol Evol 2022; 39:6586215. [PMID: 35574644 PMCID: PMC9132207 DOI: 10.1093/molbev/msac102] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Balancing selection is a classic mechanism for maintaining variability in immune genes involved in host–pathogen interactions. However, it remains unclear how widespread the mechanism is across immune genes other than the major histocompatibility complex (MHC). Although occasional reports suggest that balancing selection (heterozygote advantage, negative frequency-dependent selection, and fluctuating selection) may act on other immune genes, the current understanding of the phenomenon in non-MHC immune genes is far from solid. In this review, we focus on Toll-like receptors (TLRs), innate immune genes directly involved in pathogen recognition and immune response activation, as there is a growing body of research testing the assumptions of balancing selection in these genes. After reviewing infection- and fitness-based evidence, along with evidence based on population allelic frequencies and heterozygosity levels, we conclude that balancing selection maintains variation in TLRs, though it tends to occur under specific conditions in certain evolutionary lineages rather than being universal and ubiquitous. Our review also identifies key gaps in current knowledge and proposes promising areas for future research. Improving our understanding of host–pathogen interactions and balancing selection in innate immune genes are increasingly important, particularly regarding threats from emerging zoonotic diseases.
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10
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Abstract
Birds are important hosts for many RNA viruses, including influenza A virus, Newcastle disease virus, West Nile virus and coronaviruses. Innate defense against RNA viruses in birds involves detection of viral RNA by pattern recognition receptors. Several receptors of different classes are involved, such as endosomal toll-like receptors and cytoplasmic retinoic acid-inducible gene I-like receptors, and their downstream adaptor proteins. The function of these receptors and their antagonism by viruses is well established in mammals; however, this has received less attention in birds. These receptors have been characterized in a few bird species, and the completion of avian genomes will permit study of their evolution. For each receptor, functional work has established ligand specificity and activation by viral infection. Engagement of adaptors, regulation by modulators and the supramolecular organization of proteins required for activation are incompletely understood in both mammals and birds. These receptors bind conserved nucleic acid agonists such as single- or double-stranded RNA and generally show purifying selection, particularly the ligand binding regions. However, in birds, these receptors and adaptors differ between species, and between individuals, suggesting that they are under selection for diversification over time. Avian receptors and signalling pathways, like their mammalian counterparts, are targets for antagonism by a variety of viruses, intent on escape from innate immune responses.
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11
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Li X, Li Q, Ruan W. Identification of Avian Toll-Like Receptor 3 and 7 and Analysis of Gene Variation Sites. BRAZILIAN JOURNAL OF POULTRY SCIENCE 2022. [DOI: 10.1590/1806-9061-2020-1431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- X Li
- Beijing University of Agriculture, China
| | - Q Li
- Beijing University of Agriculture, China
| | - W Ruan
- Beijing University of Agriculture, China
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12
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Fiddaman SR, Vinkler M, Spiro SG, Levy H, Emerling CA, Boyd AC, Dimopoulos EA, Vianna JA, Cole TL, Pan H, Fang M, Zhang G, Hart T, Frantz LAF, Smith AL. Adaptation and cryptic pseudogenization in penguin Toll-like Receptors. Mol Biol Evol 2021; 39:6460345. [PMID: 34897511 PMCID: PMC8788240 DOI: 10.1093/molbev/msab354] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Penguins (Sphenisciformes) are an iconic order of flightless, diving seabirds distributed across a large latitudinal range in the Southern Hemisphere. The extensive area over which penguins are endemic is likely to have fostered variation in pathogen pressure, which in turn will have imposed differential selective pressures on the penguin immune system. At the front line of pathogen detection and response, the Toll-like receptors (TLRs) provide insight into host evolution in the face of microbial challenge. TLRs respond to conserved pathogen-associated molecular patterns and are frequently found to be under positive selection, despite retaining specificity for defined agonist classes. We undertook a comparative immunogenetics analysis of TLRs for all penguin species and found evidence of adaptive evolution that was largely restricted to the cell surface-expressed TLRs, with evidence of positive selection at, or near, key agonist-binding sites in TLR1B, TLR4, and TLR5. Intriguingly, TLR15, which is activated by fungal products, appeared to have been pseudogenized multiple times in the Eudyptes spp., but a full-length form was present as a rare haplotype at the population level. However, in vitro analysis revealed that even the full-length form of Eudyptes TLR15 was nonfunctional, indicating an ancestral cryptic pseudogenization prior to its eventual disruption multiple times in the Eudyptes lineage. This unusual pseudogenization event could provide an insight into immune adaptation to fungal pathogens such as Aspergillus, which is responsible for significant mortality in wild and captive bird populations.
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Affiliation(s)
- Steven R Fiddaman
- Department of Zoology, University of Oxford South Parks Road, Oxford, OX1 3PS, UK
| | - Michal Vinkler
- Department of Zoology, Faculty of Science, Charles University Prague, Czech Republic
| | - Simon G Spiro
- Wildlife Health Services, Zoological Society of London Regent's Park, London, UK
| | - Hila Levy
- Department of Zoology, University of Oxford South Parks Road, Oxford, OX1 3PS, UK
| | | | - Amy C Boyd
- Jenner Institute, University of Oxford Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Evangelos A Dimopoulos
- The Palaeogenomics and Bio-Archaeology Research Network, Research Laboratory for Archaeology and History of Art, University of Oxford Oxford, UK
| | - Juliana A Vianna
- Pontificia Universidad Católica de Chile, Facultad de Agronomía e Ingeniería Forestal, Departamento de Ecosistemas y Medio Ambiente Vicuña Mackenna 4860, Macul, Santiago, Chile
| | - Theresa L Cole
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen DK2100, Copenhagen, Denmark
| | - Hailin Pan
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District Shenzhen 518083, China
| | - Miaoquan Fang
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District Shenzhen 518083, China
| | - Guojie Zhang
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen DK2100, Copenhagen, Denmark.,BGI-Shenzhen, Beishan Industrial Zone, Yantian District Shenzhen 518083, China.,State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China
| | - Tom Hart
- Department of Zoology, University of Oxford South Parks Road, Oxford, OX1 3PS, UK
| | - Laurent A F Frantz
- School of Biological and Chemical Sciences, Fogg Building, Queen Mary University of London Mile End Rd, Bethnal Green, London E1 4DQ, UK.,Institute of Palaeoanatomy, Domestication Research and the History of Veterinary Medicine, Faculty of Veterinary Medicine, Ludwig Maximilian University of Munich, Germany
| | - Adrian L Smith
- Department of Zoology, University of Oxford South Parks Road, Oxford, OX1 3PS, UK
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13
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Boyd RJ, Denommé MR, Grieves LA, MacDougall-Shackleton EA. Stronger population differentiation at infection-sensing than infection-clearing innate immune loci in songbirds: Different selective regimes for different defenses. Evolution 2021; 75:2736-2746. [PMID: 34596241 DOI: 10.1111/evo.14368] [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: 12/31/2020] [Revised: 08/30/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Parasite-mediated selection is widespread at loci involved in immune defense, but different defenses may experience different selective regimes. For defenses involved in clearing infections, purifying selection favoring a single most efficacious allele likely predominates. However, for defenses involved in sensing and recognizing infections, evolutionary arms races may make positive selection particularly important. This could manifest primarily within populations (e.g., balancing selection maintaining variation) or among them (e.g., spatially varying selection enhancing population differences in allele frequencies). We genotyped three toll-like receptors (TLR; involved in sensing infections) and three avian beta-defensins (involved in clearing infections) in 96 song sparrows (Melospiza melodia) from three breeding populations that differ in disease resistance. Variation-based indicators of selection (proportion of variable sites, proportion of nonsynonymous SNPs, proportion of sites bearing signatures of positive or purifying selection, rare allele frequencies) did not differ appreciably between the two locus types. However, differentiation was generally higher at infection-sensing than infection-clearing loci. Allele frequencies differed markedly at TLR3, driven by a variant predicted to alter protein function. Geographically structured variants at infection-sensing loci may reflect local adaptation to spatially heterogeneous parasite communities. Selective regimes experienced by infection-sensing versus infection-clearing loci may differ primarily due to parasite-mediated population differentiation.
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Affiliation(s)
- Rachel J Boyd
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7, Canada.,McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205
| | - Melanie R Denommé
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7, Canada.,Department of Biological Sciences, Brock University Faculty of Mathematics & Science, St. Catherines, Ontario, L2S 3A1, Canada
| | - Leanne A Grieves
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7, Canada.,Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, L8S 4M4, Canada
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14
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Minias P, Drzewińska-Chańko J, Włodarczyk R. Evolution of innate and adaptive immune genes in a non-model waterbird, the common tern. INFECTION GENETICS AND EVOLUTION 2021; 95:105069. [PMID: 34487864 DOI: 10.1016/j.meegid.2021.105069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/28/2021] [Accepted: 09/01/2021] [Indexed: 11/25/2022]
Abstract
Toll-like receptors (TLRs) and the Major Histocompatibility Complex (MHC) are the key pathogen-recognition genes of vertebrate immune system and they have a crucial role in the initiation of innate and adaptive immune response, respectively. Recent advancements in sequencing technology sparked research on highly duplicated MHC genes in non-model species, but TLR variation in natural vertebrate populations has remained little studied and comparisons of polymorphism across both TLRs and MHC are scarce. Here, we aimed to compare variation across innate (four TLR loci) and adaptive (MHC class I and class II) immune genes in a non-model avian species, the common tern Sterna hirundo. We detected relatively high allelic richness at TLR genes (9-48 alleles per locus), which was similar to or even higher than the estimated per locus allelic richness at the MHC (24-30 alleles at class I and 13-16 alleles at class II under uniform sample sizes). Despite this, the total number of MHC alleles across all duplicated loci (four class I and three class II) was much higher and MHC alleles showed greater sequence divergence than TLRs. Positive selection targeted relatively more sites at the MHC than TLRs, but the strength of selection (dN/dS ratios) at TLRs was higher when compared to MHC class I. There were also differences in the signature of positive selection and recombination (gene conversion) between MHC class I and II (stronger signature at class II), suggesting that mechanisms maintaining variation at the MHC may vary between both classes. Our study indicates that allelic richness of both innate and adaptive immune receptors may be maintained at relatively high levels in viable avian populations and we recommend a transition from the traditional gene-specific to multi-gene approach in studying molecular evolution of vertebrate immune system.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland.
| | - Joanna Drzewińska-Chańko
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
| | - Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
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15
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Schwartz B, Vetvicka V. Review: β-glucans as Effective Antibiotic Alternatives in Poultry. Molecules 2021; 26:molecules26123560. [PMID: 34200882 PMCID: PMC8230556 DOI: 10.3390/molecules26123560] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/01/2021] [Accepted: 06/08/2021] [Indexed: 02/07/2023] Open
Abstract
The occurrence of microbial challenges in commercial poultry farming causes significant economic losses. Antibiotics have been used to control diseases involving bacterial infection in poultry. As the incidence of antibiotic resistance turns out to be a serious problem, there is increased pressure on producers to reduce antibiotic use. With the reduced availability of antibiotics, poultry producers are looking for feed additives to stimulate the immune system of the chicken to resist microbial infection. Some β-glucans have been shown to improve gut health, to increase the flow of new immunocytes, increase macrophage function, stimulate phagocytosis, affect intestinal morphology, enhance goblet cell number and mucin-2 production, induce the increased expression of intestinal tight-junctions, and function as effective anti-inflammatory immunomodulators in poultry. As a result, β-glucans may provide a new tool for producers trying to reduce or eliminate the use of antibiotics in fowl diets. The specific activity of each β-glucan subtype still needs to be investigated. Upon knowledge, optimal β-glucan mixtures may be implemented in order to obtain optimal growth performance, exert anti-inflammatory and immunomodulatory activity, and optimized intestinal morphology and histology responses in poultry. This review provides an extensive overview of the current use of β glucans as additives and putative use as antibiotic alternative in poultry.
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Affiliation(s)
- Betty Schwartz
- Institute of Biochemistry, Food Science and Nutrition, The School of Nutritional Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 761001, Israel
- Correspondence:
| | - Vaclav Vetvicka
- Department of Pathology, University of Louisville, Louisville, KY 40202, USA;
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16
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Zapata D, Rivera-Gutierrez HF, Parra JL, Gonzalez-Quevedo C. Low adaptive and neutral genetic diversity in the endangered Antioquia wren (Thryophilus sernai). CONSERV GENET 2020. [DOI: 10.1007/s10592-020-01313-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Suklek A, Kayan A, Rattanasrisomporn J, Boonkaewwan C. Isolation of peripheral blood mononuclear cells and the expression of toll-like receptors in Betong chickens. Vet World 2020; 13:1372-1375. [PMID: 32848313 PMCID: PMC7429389 DOI: 10.14202/vetworld.2020.1372-1375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/19/2020] [Indexed: 12/26/2022] Open
Abstract
Background and Aim: Toll-like receptors (TLRs) comprise microbial sensing receptors present on cell surfaces that are capable of detecting pathogens. The present study aims to examine the expression of TLRs within the peripheral blood mononuclear cell (PBMC) of the Betong chickens. Materials and Methods: Blood samples were harvested from 12 Betong (KU line) chickens. Hematological values were calculated. PBMC was isolated from the blood utilizing a Histopaque solution and stored in a RPMI1640 culture medium. Cell viability was investigated using a Trypan Blue dye exclusion test. DNA was extracted from PBMC and the expression of the DNA’s TLRs was examined using a polymerase chain reaction. Results: Hematological values were determined from the blood samples collected in this study obtained from healthy Betong chickens. PBMC that was isolated from the Betong chickens possessed cell viability higher than 95% (95.37±1.06). From the examination of TLRs gene expression, results revealed instances of TLR1.1, TLR1.2, TLR2.1, TLR2.2, TLR3, TLR4, TLR5, TLR 7, TLR15, and TLR21 that were present in the PBMC of Betong chickens. Conclusion: PBMC isolated from the blood of healthy Betong chickens possessed excellent cell quality. All chicken TLRs were discovered within the PBMC of Betong chickens. Hence, PBMC stands out as one of the premier sources for in vitro studies of chicken immune response.
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Affiliation(s)
- Anutian Suklek
- Department of Animal Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Autchara Kayan
- Department of Animal Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | - Jatuporn Rattanasrisomporn
- Department of Companion Animal Clinical Science, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
| | - Chaiwat Boonkaewwan
- Department of Animal Science, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.,Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat 80161, Thailand
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18
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Těšický M, Velová H, Novotný M, Kreisinger J, Beneš V, Vinkler M. Positive selection and convergent evolution shape molecular phenotypic traits of innate immunity receptors in tits (Paridae). Mol Ecol 2020; 29:3056-3070. [PMID: 32652716 DOI: 10.1111/mec.15547] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/09/2020] [Accepted: 06/26/2020] [Indexed: 01/04/2023]
Abstract
Despite widespread variability and redundancy abounding animal immunity, little is currently known about the rate of evolutionary convergence (functionally analogous traits not inherited from a common ancestor) in host molecular adaptations to parasite selective pressures. Toll-like receptors (TLRs) provide the molecular interface allowing hosts to recognize pathogenic structures and trigger early danger signals initiating an immune response. Using a novel combination of bioinformatic approaches, here we explore genetic variation in ligand-binding regions of bacteria-sensing TLR4 and TLR5 in 29 species belonging to the tit family of passerine birds (Aves: Paridae). Three out of the four consensual positively selected sites in TLR4 and six out of 14 positively selected positions in TLR5 were located on the receptor surface near the functionally important sites, and based on the phylogenetic pattern evolved in a convergent (parallel) manner. This type of evolution was also seen at one N-glycosylation site and two positively selected phosphorylation sites, providing the first evidence of convergence in post-translational modifications in evolutionary immunology. Finally, the overall mismatch between phylogeny and the clustering of surface charge distribution demonstrates that convergence is common in overall TLR4 and TLR5 molecular phenotypes involved in ligand binding. Our analysis did not reveal any broad ecological traits explaining the convergence observed in electrostatic potentials, suggesting that information on microbial symbionts may be needed to explain TLR evolution. Adopting state-of-the-art predictive structural bionformatics, we have outlined a new broadly applicable methodological approach to estimate the functional significance of positively selected variation and test for the adaptive molecular convergence in protein-coding polymorphisms.
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Affiliation(s)
- Martin Těšický
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Hana Velová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Marian Novotný
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jakub Kreisinger
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vladimír Beneš
- European Molecular Laboratory Heidelberg, Heidelberg, Germany
| | - Michal Vinkler
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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19
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Levy H, Fiddaman SR, Vianna JA, Noll D, Clucas GV, Sidhu JKH, Polito MJ, Bost CA, Phillips RA, Crofts S, Miller GD, Pistorius P, Bonnadonna F, Le Bohec C, Barbosa A, Trathan P, Raya Rey A, Frantz LAF, Hart T, Smith AL. Evidence of Pathogen-Induced Immunogenetic Selection across the Large Geographic Range of a Wild Seabird. Mol Biol Evol 2020; 37:1708-1726. [PMID: 32096861 PMCID: PMC7253215 DOI: 10.1093/molbev/msaa040] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Over evolutionary time, pathogen challenge shapes the immune phenotype of the host to better respond to an incipient threat. The extent and direction of this selection pressure depend on the local pathogen composition, which is in turn determined by biotic and abiotic features of the environment. However, little is known about adaptation to local pathogen threats in wild animals. The Gentoo penguin (Pygoscelis papua) is a species complex that lends itself to the study of immune adaptation because of its circumpolar distribution over a large latitudinal range, with little or no admixture between different clades. In this study, we examine the diversity in a key family of innate immune genes-the Toll-like receptors (TLRs)-across the range of the Gentoo penguin. The three TLRs that we investigated present varying levels of diversity, with TLR4 and TLR5 greatly exceeding the diversity of TLR7. We present evidence of positive selection in TLR4 and TLR5, which points to pathogen-driven adaptation to the local pathogen milieu. Finally, we demonstrate that two positively selected cosegregating sites in TLR5 are sufficient to alter the responsiveness of the receptor to its bacterial ligand, flagellin. Taken together, these results suggest that Gentoo penguins have experienced distinct pathogen-driven selection pressures in different environments, which may be important given the role of the Gentoo penguin as a sentinel species in some of the world's most rapidly changing environments.
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Affiliation(s)
- Hila Levy
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Juliana A Vianna
- Departamento de Ecosistemas y Medio Ambiente, Pontificia Universidad Católica de Chile, Macul, Santiago, Chile
| | - Daly Noll
- Departamento de Ecosistemas y Medio Ambiente, Pontificia Universidad Católica de Chile, Macul, Santiago, Chile
- Departamento de Ciencias Ecológicas, Instituto de Ecología y Biodiversidad, Universidad de Chile, Santiago, Chile
| | - Gemma V Clucas
- Cornell Atkinson Center for a Sustainable Future, Cornell University, Ithaca, NY
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY
| | | | - Michael J Polito
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA
| | - Charles A Bost
- Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS‐Université de La Rochelle, Villiers‐en‐Bois, France
| | | | - Sarah Crofts
- Falklands Conservation, Stanley, Falkland Islands, United Kingdom
| | - Gary D Miller
- Microbiology and Immunology, PALM, University of Western Australia, Crawley, Western Australia, Australia
| | - Pierre Pistorius
- DST/NRF Centre of Excellence at the Percy FitzPatrick Institute for African Ornithology, Department of Zoology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Francesco Bonnadonna
- CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, Montpellier, France
| | - Céline Le Bohec
- Université de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
- Département de Biologie Polaire, Centre Scientifique de Monaco, Monaco, Principality of Monaco
| | - Andrés Barbosa
- Museo Nacional de Ciencias Naturales, Departamento de Ecología Evolutiva, CSIC, Madrid, Spain
| | - Phil Trathan
- British Antarctic Survey, Cambridge, United Kingdom
| | - Andrea Raya Rey
- Centro Austral de Investigaciones Científicas – Consejo Nacional de Investigaciones Científicas y Técnicas (CADIC-CONICET), Ushuaia, Tierra del Fuego, Argentina
- Instituto de Ciencias Polares, Ambiente y Recursos Naturales, Universidad Nacional de Tierra del Fuego, Ushuaia, Tierra del Fuego, Argentina
- Wildlife Conservation Society, Buenos Aires, Argentina
| | - Laurent A F Frantz
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Tom Hart
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Adrian L Smith
- Department of Zoology, University of Oxford, Oxford, United Kingdom
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20
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Freem L, Summers KM, Gheyas AA, Psifidi A, Boulton K, MacCallum A, Harne R, O’Dell J, Bush SJ, Hume DA. Analysis of the Progeny of Sibling Matings Reveals Regulatory Variation Impacting the Transcriptome of Immune Cells in Commercial Chickens. Front Genet 2019; 10:1032. [PMID: 31803225 PMCID: PMC6870463 DOI: 10.3389/fgene.2019.01032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/25/2019] [Indexed: 01/05/2023] Open
Abstract
There is increasing recognition that the underlying genetic variation contributing to complex traits influences transcriptional regulation and can be detected at a population level as expression quantitative trait loci. At the level of an individual, allelic variation in transcriptional regulation of individual genes can be detected by measuring allele-specific expression in RNAseq data. We reasoned that extreme variants in gene expression could be identified by analysis of inbred progeny with shared grandparents. Commercial chickens have been intensively selected for production traits. Selection is associated with large blocks of linkage disequilibrium with considerable potential for co-selection of closely linked "hitch-hiker alleles" affecting traits unrelated to the feature being selected, such as immune function, with potential impact on the productivity and welfare of the animals. To test this hypothesis that there is extreme allelic variation in immune-associated genes we sequenced a founder population of commercial broiler and layer birds. These birds clearly segregated genetically based upon breed type. Each genome contained numerous candidate null mutations, protein-coding variants predicted to be deleterious and extensive non-coding polymorphism. We mated selected broiler-layer pairs then generated cohorts of F2 birds by sibling mating of the F1 generation. Despite the predicted prevalence of deleterious coding variation in the genomic sequence of the founders, clear detrimental impacts of inbreeding on survival and post-hatch development were detected in only one F2 sibship of 15. There was no effect on circulating leukocyte populations in hatchlings. In selected F2 sibships we performed RNAseq analysis of the spleen and isolated bone marrow-derived macrophages (with and without lipopolysaccharide stimulation). The results confirm the predicted emergence of very large differences in expression of individual genes and sets of genes. Network analysis of the results identified clusters of co-expressed genes that vary between individuals and suggested the existence of trans-acting variation in the expression in macrophages of the interferon response factor family that distinguishes the parental broiler and layer birds and influences the global response to lipopolysaccharide. This study shows that the impact of inbreeding on immune cell gene expression can be substantial at the transcriptional level, and potentially opens a route to accelerate selection using specific alleles known to be associated with desirable expression levels.
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Affiliation(s)
- Lucy Freem
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Kim M. Summers
- Mater Research Institute-University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Almas A. Gheyas
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Androniki Psifidi
- Department of Clinical Sciences and Services, Royal Veterinary College, University of London, London, United Kingdom
| | - Kay Boulton
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Amanda MacCallum
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Rakhi Harne
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Jenny O’Dell
- The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen J. Bush
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - David A. Hume
- Mater Research Institute-University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
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21
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Näpflin K, O’Connor EA, Becks L, Bensch S, Ellis VA, Hafer-Hahmann N, Harding KC, Lindén SK, Olsen MT, Roved J, Sackton TB, Shultz AJ, Venkatakrishnan V, Videvall E, Westerdahl H, Winternitz JC, Edwards SV. Genomics of host-pathogen interactions: challenges and opportunities across ecological and spatiotemporal scales. PeerJ 2019; 7:e8013. [PMID: 31720122 PMCID: PMC6839515 DOI: 10.7717/peerj.8013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022] Open
Abstract
Evolutionary genomics has recently entered a new era in the study of host-pathogen interactions. A variety of novel genomic techniques has transformed the identification, detection and classification of both hosts and pathogens, allowing a greater resolution that helps decipher their underlying dynamics and provides novel insights into their environmental context. Nevertheless, many challenges to a general understanding of host-pathogen interactions remain, in particular in the synthesis and integration of concepts and findings across a variety of systems and different spatiotemporal and ecological scales. In this perspective we aim to highlight some of the commonalities and complexities across diverse studies of host-pathogen interactions, with a focus on ecological, spatiotemporal variation, and the choice of genomic methods used. We performed a quantitative review of recent literature to investigate links, patterns and potential tradeoffs between the complexity of genomic, ecological and spatiotemporal scales undertaken in individual host-pathogen studies. We found that the majority of studies used whole genome resolution to address their research objectives across a broad range of ecological scales, especially when focusing on the pathogen side of the interaction. Nevertheless, genomic studies conducted in a complex spatiotemporal context are currently rare in the literature. Because processes of host-pathogen interactions can be understood at multiple scales, from molecular-, cellular-, and physiological-scales to the levels of populations and ecosystems, we conclude that a major obstacle for synthesis across diverse host-pathogen systems is that data are collected on widely diverging scales with different degrees of resolution. This disparity not only hampers effective infrastructural organization of the data but also data granularity and accessibility. Comprehensive metadata deposited in association with genomic data in easily accessible databases will allow greater inference across systems in the future, especially when combined with open data standards and practices. The standardization and comparability of such data will facilitate early detection of emerging infectious diseases as well as studies of the impact of anthropogenic stressors, such as climate change, on disease dynamics in humans and wildlife.
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Affiliation(s)
- Kathrin Näpflin
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America
| | - Emily A. O’Connor
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Lutz Becks
- Aquatic Ecology and Evolution, Limnological Institute University Konstanz, Konstanz, Germany
| | - Staffan Bensch
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Vincenzo A. Ellis
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Nina Hafer-Hahmann
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
- EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Karin C. Harding
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden
| | - Sara K. Lindén
- Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Morten T. Olsen
- Section for Evolutionary Genomics, Natural History Museum of Denmark, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Roved
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Timothy B. Sackton
- Informatics Group, Harvard University, Cambridge, MA, United States of America
| | - Allison J. Shultz
- Ornithology Department, Natural History Museum of Los Angeles County, Los Angeles, CA, United States of America
| | - Vignesh Venkatakrishnan
- Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elin Videvall
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
- Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, United States of America
| | - Helena Westerdahl
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Lund, Sweden
| | - Jamie C. Winternitz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Scott V. Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America
- Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology and University of Gothenburg, Gothenburg, Sweden
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22
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Nawab A, An L, Wu J, Li G, Liu W, Zhao Y, Wu Q, Xiao M. Chicken toll-like receptors and their significance in immune response and disease resistance. Int Rev Immunol 2019; 38:284-306. [PMID: 31662000 DOI: 10.1080/08830185.2019.1659258] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Infectious diseases are a major challenge for the poultry industry that causes widespread production losses. Thus, management and control of poultry health and diseases are essential for the viability of the industry. Toll-like receptors are best characterized as membrane-bound receptors that perform a central role in immune homeostasis and disease resistance by recognition of pathogen-associated molecular patterns. In response to pathogen recognition, TLRs initiate both innate and adaptive immune responses which may help to develop immunomodulatory therapeutics for TLR associated diseases. Vaccination produces specific immunity in the animal's body towards pathogens. However, due to certain disadvantages of vaccines, (inactivation of attenuated pathogens into the virulent strains and weak immunogenicity of inactivated vaccines) there is a crucial need to develop the safe and effective therapeutic intervention. TLR ligands have been classified as a potential adjuvant against the infectious diseases in farm animals. TLR adjuvants induce both specific and nonspecific immune responses in chickens to combat several bacterial, viral and parasitic diseases. Therefore, the aim of this review was to explore the chicken TLR4 and their role in immune responses and disease resistance to develop disease resistance poultry breeds in future.
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Affiliation(s)
- Aamir Nawab
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China.,Faculty of Veterinary Medicine, PMAS- Arid Agriculture University Rawalpindi, Rawalpindi, Pakistan
| | - Lilong An
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Jiang Wu
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Guanghui Li
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Wenchao Liu
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Yi Zhao
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Qimin Wu
- Mechanical and Power Engineering College, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Mei Xiao
- Department of Animal Science, Guangdong Ocean University, Zhanjiang, Guangdong, China
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