1
|
TLR4 and MD2 variation among horses with differential TNFα baseline concentrations and response to intravenous lipopolysaccharide infusion. Sci Rep 2023; 13:1486. [PMID: 36707633 PMCID: PMC9883502 DOI: 10.1038/s41598-023-27956-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 01/10/2023] [Indexed: 01/28/2023] Open
Abstract
Gram-negative bacterial septicemia is mediated through binding of lipopolysaccharide (LPS) to mammalian toll-like receptor protein 4 (TLR4). TLR4 and its cognate protein, myeloid differentiation factor 2 (MD2) form a heterodimeric complex after binding LPS. This complex induces a cascade of reactions that results in increased proinflammatory cytokine gene expression, including TNFα, which leads to activation of innate immunity. In horses, the immune response to LPS varies widely. To determine if this variation is due to differences in TLR4 or MD2, DNA from 15 healthy adult horses with different TNFα dynamics after experimental intravenous LPS infusion was sequenced across exons of TLR4 and MD2. Haplotypes were constructed for both genes using all identified variants. Four haplotypes were observed for each gene. No significant associations were found between either TNFα baseline concentrations or response to LPS and haplotype; however, there was a significant association (P value = 0.0460) between the baseline TNFα concentration and one MD2 missense variant. Three-dimensional structures of the equine TLR4-MD2-LPS complex were built according to haplotype combinations observed in the study horses, and the implications of missense variants on LPS binding were modeled. Although the sample size was small, there was no evidence that variation in TLR4 or MD2 explains the variability in TNFα response observed after LPS exposure in horses.
Collapse
|
2
|
Tallmadge RL, Antczak DF, Felippe MJB. Genetics of Immune Disease in the Horse. Vet Clin North Am Equine Pract 2020; 36:273-288. [PMID: 32654783 DOI: 10.1016/j.cveq.2020.03.007] [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] [Indexed: 01/22/2023] Open
Abstract
Host defenses against infection by viruses, bacteria, fungi, and parasites are critical to survival. It has been estimated that upwards of 7% of the coding genes of mammals function in immunity and inflammation. This high level of genomic investment in defense has resulted in an immune system characterized by extraordinary complexity and many levels of redundancy. Because so many genes are involved with immunity, there are many opportunities for mutations to arise that have negative effects. However, redundancy in the mammalian defense system and the adaptive nature of key immune mechanisms buffer the untoward outcomes of many such deleterious mutations.
Collapse
Affiliation(s)
- Rebecca L Tallmadge
- Animal Health Diagnostic Center, College of Veterinary Medicine, Cornell University, 240 Farrier Road, Ithaca, NY 14853, USA
| | - Douglas F Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, 235 Hungerford Hill Road, Ithaca, NY 14853, USA.
| | - Maria Julia Bevilaqua Felippe
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, 930 Campus Road, Ithaca, NY 14853, USA
| |
Collapse
|
3
|
Hellman S, Hjertner B, Morein B, Fossum C. The adjuvant G3 promotes a Th1 polarizing innate immune response in equine PBMC. Vet Res 2018; 49:108. [PMID: 30348190 PMCID: PMC6389152 DOI: 10.1186/s13567-018-0602-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/01/2018] [Indexed: 12/11/2022] Open
Abstract
The immunomodulatory effect of a new particulate adjuvant, G3, alone or in combination with agonists to TLR2/1 or TLR5 was evaluated in cultures of equine PBMC. Exposure to the G3 adjuvant up-regulated genes encoding IFN-γ, IL-1β, IL-6, IL-8, IL-12p40 and IL-23p19 in the majority of the horses tested, indicating that the G3 adjuvant induced a pro-inflammatory and Th1 dominated profile. In accordance, genes encoding IL-13, IL-4, IL-10 and TGF-β remained unaffected and genes encoding IFN-α, IL-17A and TNF-α were only occasionally and weakly induced. The two TLR agonists Pam3CSK4 (TLR2/1) and FliC (TLR5) induced cytokine profiles characterized by a clear induction of IL-10 as well as up-regulation of the genes encoding IL-1β, IL-6 and IL-8. The presence of G3 modified this response, in particular by reducing the FliC and Pam3CSK4 induced production of IL-10. Furthermore, G3 acted in synergy with Pam3CSK4 in enhancing the production of IFN-γ whereas G3 combined with FliC increased the gene expression of IL-8. Thus, the G3 adjuvant seems to have the capacity to promote a Th1 polarizing innate immune response in eqPBMC, both by favouring IFN-γ production and by reducing production of IL-10 induced by co-delivered molecules. These features make G3 an interesting candidate to further evaluate for its potential as an adjuvant in equine vaccines.
Collapse
Affiliation(s)
- Stina Hellman
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SLU, Box 7028, 750 07, Uppsala, Sweden.
| | - Bernt Hjertner
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SLU, Box 7028, 750 07, Uppsala, Sweden
| | - Bror Morein
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SLU, Box 7028, 750 07, Uppsala, Sweden
| | - Caroline Fossum
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SLU, Box 7028, 750 07, Uppsala, Sweden
| |
Collapse
|
4
|
McQueen CM, Whitfield-Cargile CM, Konganti K, Blodgett GP, Dindot SV, Cohen ND. TRPM2 SNP genotype previously associated with susceptibility to Rhodococcus equi pneumonia in Quarter Horse foals displays differential gene expression identified using RNA-Seq. BMC Genomics 2016; 17:993. [PMID: 27919223 PMCID: PMC5139010 DOI: 10.1186/s12864-016-3345-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/25/2016] [Indexed: 01/02/2023] Open
Abstract
Background Rhodococcus equi (R. equi) is an intracellular bacterium that affects young foals and immuno-compromised individuals causing severe pneumonia. Currently, the genetic mechanisms that confer susceptibility and/or resistance to R. equi are not fully understood. Previously, using a SNP-based genome-wide association study, we identified a region on equine chromosome 26 associated with culture-confirmed clinical pneumonia. To better characterize this region and understand the function of the SNP located within TRPM2 that was associated with R. equi pneumonia, we performed RNA-Seq on 12 horses representing the 3 genotypic forms of this SNP. Results We identified differentially expressed genes in the innate immune response pathway when comparing homozygous A allele horses with the AB and BB horses. Isoform analyses of the RNA-Seq data predicted the existence of multiple transcripts and provided evidence of differential expression at the TRPM2 locus. This finding is consistent with previously demonstrated work in human cell lines in which isoform-specific expression of TRPM2 was critical for cell viability. Conclusions This work demonstrates that SNPs in TRPM2 are associated with differences in gene expression, suggesting that modulation of expression of this innate immune gene contributes to susceptibility to R. equi pneumonia.
Collapse
Affiliation(s)
- Cole M McQueen
- Department of Large Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine & Biomedical Sciences, College Station, TX, USA
| | - Canaan M Whitfield-Cargile
- Department of Large Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine & Biomedical Sciences, College Station, TX, USA
| | - Kranti Konganti
- Texas A&M Institute for Genome Sciences and Society, Texas A&M University, College Station, TX, USA.,Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine & Biomedical Sciences, College Station, TX, USA
| | | | - Scott V Dindot
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine & Biomedical Sciences, College Station, TX, USA.
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, Texas A&M University College of Veterinary Medicine & Biomedical Sciences, College Station, TX, USA.
| |
Collapse
|
5
|
McQueen CM, Dindot SV, Foster MJ, Cohen ND. Genetic Susceptibility to Rhodococcus equi. J Vet Intern Med 2015; 29:1648-59. [PMID: 26340305 PMCID: PMC4895676 DOI: 10.1111/jvim.13616] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/29/2015] [Accepted: 08/10/2015] [Indexed: 02/02/2023] Open
Abstract
Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments for R. equi with limited success. With a growing focus in the medical community on understanding the genetic basis of disease susceptibility, investigators have begun to evaluate the interaction of the genetics of the foal with R. equi. This review describes past efforts to understand the genetic basis underlying R. equi susceptibility and tolerance. It also highlights the genetic technology available to study horses and describes the use of this technology in investigating R. equi. This review provides readers with a foundational understanding of candidate gene approaches, single nucleotide polymorphism‐based, and copy number variant‐based genome‐wide association studies, and next generation sequencing (both DNA and RNA).
Collapse
Affiliation(s)
- C M McQueen
- Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX
| | - S V Dindot
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX
| | - M J Foster
- Medical Sciences Library, Texas A&M University, College Station, TX
| | - N D Cohen
- Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX
| |
Collapse
|
6
|
|
7
|
The equine immune responses to infectious and allergic disease: a model for humans? Mol Immunol 2014; 66:89-96. [PMID: 25457878 DOI: 10.1016/j.molimm.2014.09.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/23/2014] [Accepted: 09/29/2014] [Indexed: 01/01/2023]
Abstract
The modern horse, Equus caballus has historically made important contributions to the field of immunology, dating back to Emil von Behring's description of curative antibodies in equine serum over a century ago. While the horse continues to play an important role in human serotherapy, the mouse has replaced the horse as the predominant experimental animal in immunology research. Nevertheless, continuing efforts have led to an improved understanding of the equine immune response in a variety of infectious and non-infectious diseases. Based on this information, we can begin to identify specific situations where the horse may provide a unique immunological model for certain human diseases.
Collapse
|
8
|
Rusek J, Klumplerova M, Molinkova D, Sedlinska M, Dusek L, Muzik J, Putnova L, Vrtkova I, Celer V, Horin P. Genetics of anti-EHV antibody responses in a horse population. Res Vet Sci 2013; 95:137-42. [DOI: 10.1016/j.rvsc.2013.03.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 01/16/2013] [Accepted: 03/17/2013] [Indexed: 10/26/2022]
|
9
|
Kalemkerian P, Metz G, Peral-Garcia P, Echeverria M, Giovambattista G, Díaz S. ELA-DRA polymorphisms are not associated with Equine Arteritis Virus infection in horses from Argentina. Res Vet Sci 2012; 93:1271-3. [DOI: 10.1016/j.rvsc.2012.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 10/28/2022]
|
10
|
Schurink A, Wolc A, Ducro BJ, Frankena K, Garrick DJ, Dekkers JCM, van Arendonk JAM. Genome-wide association study of insect bite hypersensitivity in two horse populations in the Netherlands. Genet Sel Evol 2012; 44:31. [PMID: 23110538 PMCID: PMC3524047 DOI: 10.1186/1297-9686-44-31] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/19/2012] [Indexed: 01/09/2023] Open
Abstract
Background Insect bite hypersensitivity is a common allergic disease in horse populations worldwide. Insect bite hypersensitivity is affected by both environmental and genetic factors. However, little is known about genes contributing to the genetic variance associated with insect bite hypersensitivity. Therefore, the aim of our study was to identify and quantify genomic associations with insect bite hypersensitivity in Shetland pony mares and Icelandic horses in the Netherlands. Methods Data on 200 Shetland pony mares and 146 Icelandic horses were collected according to a matched case–control design. Cases and controls were matched on various factors (e.g. region, sire) to minimize effects of population stratification. Breed-specific genome-wide association studies were performed using 70 k single nucleotide polymorphisms genotypes. Bayesian variable selection method Bayes-C with a threshold model implemented in GenSel software was applied. A 1 Mb non-overlapping window approach that accumulated contributions of adjacent single nucleotide polymorphisms was used to identify associated genomic regions. Results The percentage of variance explained by all single nucleotide polymorphisms was 13% in Shetland pony mares and 28% in Icelandic horses. The 20 non-overlapping windows explaining the largest percentages of genetic variance were found on nine chromosomes in Shetland pony mares and on 14 chromosomes in Icelandic horses. Overlap in identified associated genomic regions between breeds would suggest interesting candidate regions to follow-up on. Such regions common to both breeds (within 15 Mb) were found on chromosomes 3, 7, 11, 20 and 23. Positional candidate genes within 2 Mb from the associated windows were identified on chromosome 20 in both breeds. Candidate genes are within the equine lymphocyte antigen class II region, which evokes an immune response by recognizing many foreign molecules. Conclusions The genome-wide association study identified several genomic regions associated with insect bite hypersensitivity in Shetland pony mares and Icelandic horses. On chromosome 20, associated genomic regions in both breeds were within 2 Mb from the equine lymphocyte antigen class II region. Increased knowledge on insect bite hypersensitivity associated genes will contribute to our understanding of its biology, enabling more efficient selection, therapy and prevention to decrease insect bite hypersensitivity prevalence.
Collapse
Affiliation(s)
- Anouk Schurink
- Animal Breeding and Genomics Centre, Wageningen University, P,O, Box 338, Wageningen, 6700 AH, the Netherlands
| | | | | | | | | | | | | |
Collapse
|
11
|
Page A, Fallon L, Bryant U, Horohov D, Luna T, Marsh P, Slovis N, Sprayberry K, Loynachan A. Acute Deterioration and Death with Necrotizing Enteritis Associated withLawsonia intracellularisin 4 Weanling Horses. J Vet Intern Med 2012; 26:1476-80. [DOI: 10.1111/j.1939-1676.2012.01002.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 05/17/2012] [Accepted: 08/13/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- A.E. Page
- Department of Veterinary Science; University of Kentucky; Lexington; KY
| | - L.H. Fallon
- Hagyard Equine Medical Institute; Lexington; KY
| | - U.K. Bryant
- Veterinary Diagnostic Laboratory; University of Kentucky; Lexington; KY
| | - D.W. Horohov
- Department of Veterinary Science; University of Kentucky; Lexington; KY
| | - T.W. Luna
- Equine Medical Associates; PSC; Lexington; KY
| | - P.S. Marsh
- Equine Medical Associates; PSC; Lexington; KY
| | - N.M. Slovis
- Hagyard Equine Medical Institute; Lexington; KY
| | | | - A.T. Loynachan
- Veterinary Diagnostic Laboratory; University of Kentucky; Lexington; KY
| |
Collapse
|
12
|
Schurink A, Ducro BJ, Bastiaansen JWM, Frankena K, van Arendonk JAM. Genome-wide association study of insect bite hypersensitivity in Dutch Shetland pony mares. Anim Genet 2012; 44:44-52. [DOI: 10.1111/j.1365-2052.2012.02368.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2012] [Indexed: 11/30/2022]
Affiliation(s)
- A. Schurink
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - B. J. Ducro
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - J. W. M. Bastiaansen
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - K. Frankena
- Quantitative Veterinary Epidemiology Group; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - J. A. M. van Arendonk
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| |
Collapse
|
13
|
Characterization of the interferon gamma response to Lawsonia intracellularis using an equine proliferative enteropathy challenge (EPE) model. Vet Immunol Immunopathol 2011; 143:55-65. [DOI: 10.1016/j.vetimm.2011.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/20/2011] [Accepted: 06/02/2011] [Indexed: 11/22/2022]
|
14
|
Kalemkerian PB, Metz GE, Peral-García P, Lopez-Gappa J, Echeverría MG, Giovambattista G, Díaz S. Eca20 microsatellite polymorphisms in equine viral arteritis-infected horses from Argentina. ACTA ACUST UNITED AC 2011; 78:281-4. [PMID: 21812763 DOI: 10.1111/j.1399-0039.2011.01743.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P = 0.0781). However, in particular alleles, Fisher exact test and odds ratio calculations showed significant values >1 for TKY08 and LEX52, and <1 for UM011, TKY08, LEX52 and VHL20. Interestingly, TKY08 STR is located in ELA class I region.
Collapse
Affiliation(s)
- P B Kalemkerian
- Instituto de Genética Veterinaria Ing. Fernando N Dulout (IGEVET)-CCT La Plata-CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina
| | | | | | | | | | | | | |
Collapse
|
15
|
Dunowska M, Howe L, Hanlon D, Stevenson M. Kinetics of Equid herpesvirus type 2 infections in a group of Thoroughbred foals. Vet Microbiol 2011; 152:176-80. [DOI: 10.1016/j.vetmic.2011.04.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 04/08/2011] [Accepted: 04/14/2011] [Indexed: 01/08/2023]
|
16
|
Vranova M, Alloggio I, Qablan M, Vyskocil M, Baumeisterova A, Sloboda M, Putnova L, Vrtkova I, Modry D, Horin P. Genetic diversity of the class II major histocompatibility DRA locus in European, Asiatic and African domestic donkeys. INFECTION GENETICS AND EVOLUTION 2011; 11:1136-41. [PMID: 21515411 DOI: 10.1016/j.meegid.2011.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 04/06/2011] [Accepted: 04/07/2011] [Indexed: 11/27/2022]
Abstract
The major histocompatibility complex (MHC) genes coding for antigen presenting molecules are the most polymorphic genes in vertebrate genome. The MHC class II DRA gene shows only small variation in many mammalian species, but it exhibits relatively high level of polymorphism in Equidae, especially in donkeys. This extraordinary degree of polymorphism together with signatures of selection in specific amino acids sites makes the donkey DRA gene a suitable model for population diversity studies. The objective of this study was to investigate the DRA gene diversity in three different populations of donkeys under infectious pressure of protozoan parasites, Theileria equi and Babesia caballi. Three populations of domestic donkeys from Italy (N = 68), Jordan (N = 43), and Kenya (N = 78) were studied. A method of the donkey MHC DRA genotyping based on PCR-RFLP and sequencing was designed. In addition to the DRA gene, 12 polymorphic microsatellite loci were genotyped. The presence of Theileria equi and Babesia caballi parasites in peripheral blood was investigated by PCR. Allele and genotype frequencies, observed and expected heterozygosities and F(IS) values were computed as parameters of genetic diversity for all loci genotyped. Genetic distances between the three populations were estimated based on F(ST) values. Statistical associations between parasite infection and genetic polymorphisms were sought. Extensive DRA locus variation characteristic for Equids was found. The results showed differences between populations both in terms of numbers of alleles and their frequencies as well as variation in expected heterozygosity values. Based on comparisons with neutral microsatellite loci, population sub-structure characteristics and association analysis, convincing evidence of pathogen-driven selection at the population level was not provided. It seems that genetic diversity observed in the three populations reflects mostly effects of selective breeding and their different genetic origins.
Collapse
Affiliation(s)
- Marie Vranova
- Institute of Animal Genetics, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1/3, 612 42 Brno, Czech Republic.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Heller MC, Drew CP, Jackson KA, Griffey S, Watson JL. A potential role for indoleamine 2,3-dioxygenase (IDO) in Rhodococcus equi infection. Vet Immunol Immunopathol 2010; 138:174-82. [PMID: 20739070 DOI: 10.1016/j.vetimm.2010.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 07/06/2010] [Accepted: 07/12/2010] [Indexed: 12/20/2022]
Abstract
Rhodococcus equi is a facultative intracellular bacterial pathogen of foals and immunocompromised humans that infects and proliferates within host macrophages and dendritic cells (DC). Indoleamine 2,3-dioxygenase (IDO), the initial enzyme in the tryptophan catabolism pathway, is upregulated in R. equi infected equine monocyte-derived DC and alveolar macrophages. Tryptophan requirement of R. equi for extracellular and intracellular growth was assessed. Growth of R. equi in minimal media did not require tryptophan and pharmacologic inhibition of IDO had no effect on intracellular proliferation of R. equi in equine alveolar macrophages. To investigate an immune-regulatory role for INDO in R. equi infection, IDO(-/-) (B6.129-(Indotm1Alm)/J) (n=22) and strain matched control (C57BL/6J) (n=20) mice were infected with R. equi by intraperitoneal injection, for 3 and 6 days. There was no difference in bacterial counts in liver or spleen between the two groups. Histological sections of liver and spleen were assigned inflammation scores and RT-PCR for interferon-gamma (IFNγ), tumor necrosis factor-alpha (TNFα), IL-4, IL-6, IL-10, IL-12, IL-23, forkhead box P3 (FoxP3), and transforming growth factor-beta (TGFβ) was performed on liver and spleen. Liver tissue of IDO(-/-) had higher inflammation scores at 6 days post-infection (PI) (P=0.05) and had decreased expression of TGFβ at 3 days PI (P=0.01), and FOXP3 at 3 days (P=0.02) and 6 days (P=0.03) compared to control mice. Immunostaining for FOXP3 showed lower numbers of FOXP3+ regulatory T cells in liver of IDO(-/-) mice 6 days PI. Prolonged inflammation in the liver tissue of IDO(-/-) mice corresponded with lower expression of FOXP3 and TGFβ in that tissue, and also with lower numbers of FOXP3+ regulatory T cells. We conclude that IDO expression by activated macrophages and DC plays a role in dampening the inflammatory response to R. equi infection in mice.
Collapse
MESH Headings
- Actinomycetales Infections/enzymology
- Actinomycetales Infections/immunology
- Actinomycetales Infections/veterinary
- Animals
- Cytokines/metabolism
- Dendritic Cells/enzymology
- Dendritic Cells/immunology
- Female
- Horse Diseases/enzymology
- Horse Diseases/immunology
- Horses
- In Vitro Techniques
- Indoleamine-Pyrrole 2,3,-Dioxygenase/deficiency
- Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics
- Indoleamine-Pyrrole 2,3,-Dioxygenase/immunology
- Liver/immunology
- Macrophages, Alveolar/enzymology
- Macrophages, Alveolar/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Rhodococcus equi
- Spleen/immunology
- T-Lymphocytes, Regulatory/immunology
Collapse
Affiliation(s)
- M C Heller
- Dept. of Veterinary Medicine and Epidemiology, University of California Davis, One Shields Ave., Davis, CA 95616, USA.
| | | | | | | | | |
Collapse
|
18
|
Horin P, Sabakova K, Futas J, Vychodilova L, Necesankova M. Immunity-related gene single nucleotide polymorphisms associated withRhodococcus equiinfection in foals. Int J Immunogenet 2010; 37:67-71. [DOI: 10.1111/j.1744-313x.2009.00890.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
19
|
Halbert ND, Cohen ND, Slovis NM, Faircloth J, Martens RJ. Variations in EquidSLC11A1 (NRAMP1)Genes and Associations withRhodococcus equiPneumonia in Horses. J Vet Intern Med 2006. [DOI: 10.1111/j.1939-1676.2006.tb01814.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
20
|
Musilova P, Kubickova S, Vychodilova-Krenkova L, Kralik P, Matiasovic J, Hubertova D, Rubes J, Horin P. Cytogenetic mapping of immunity-related genes in the domestic horse. Anim Genet 2006; 36:507-10. [PMID: 16293125 DOI: 10.1111/j.1365-2052.2005.01348.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chromosomal locations of 19 horse immunity-related loci (CASP1, CD14, EIF5A, FCER1A, IFNG, IL12A, IL12B, IL12RB2, IL1A, IL23A, IL4, IL6, MMP7, MS4A2, MYD88, NOS2A, PTGS2, TFRC and TLR2) were determined by fluorescence in situ hybridization. For IFNG and PTGS2, this study is a confirmation of their previously reported position. In addition, microsatellite (HMBr1) was localized in the same region as IFNG. All genes were assigned to regions of conserved synteny and the data obtained in this study enhance the comparative human-horse map. Cytogenetic localization of IL6 to ECA4q14-q21.1 suggested a new breakage point that changes the order of loci compared with HSA7. The map assignments of these loci serve as anchors for other loci and will aid in the search for candidate genes associated with traits in the horse.
Collapse
Affiliation(s)
- P Musilova
- Department of Genetics and Reproduction, Veterinary Research Institute, Brno 621 32, Czech Republic.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Kralik P, Matiasovic J, Horin P. Genetic evidence for the existence of interleukin-23 and for variation in the interleukin-12 and interleukin-12 receptor genes in the horse. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2006; 1:179-186. [PMID: 20483249 DOI: 10.1016/j.cbd.2005.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 09/11/2005] [Accepted: 09/14/2005] [Indexed: 05/29/2023]
Abstract
Immune loci, characterized by features reflecting their role in defense reactions and consequently related to evolutionary mechanisms, including polymorphisms or association with disease are suitable candidates for comparative analysis. Interleukin-12 and related cytokines are key molecules regulating natural and specific immune responses. In this study, we analyzed four horse IL12-related genes: IL23p19, IL12Rbeta2, IL12p40, and IL12p35. Genomic nucleotide sequence of the horse IL23 p19 sub-unit encoding gene was determined. The horse IL23p19 gene consists of four exons; its total mRNA length is 1004 bp, with a coding region of 579 bp. The predicted amino acid sequence of the horse IL23p19 sub-unit showed 88.0% sequence identity with the human sequence. A partial genomic sequence highly homologous to human IL12Rbeta2 suggesting existence of this gene in the horse was retrieved. Single nucleotide polymorphisms (SNPs) were identified in all four genes analyzed. PCR-RFLP genotyping was developed for selected SNPs. Inter-breed differences in allele and genotype frequencies were observed in IL12p35 SNP 242. The results showed that horse IL12-related genes are comparable to their counterparts in other mammalian species in terms of their structure and their genetic variation.
Collapse
Affiliation(s)
- Petr Kralik
- Institute of Animal Genetics, Faculty of Veterinary Medicine, Palackého 1/3, CZ-612 42 Brno, Czech Republic
| | | | | |
Collapse
|
22
|
Worley K, Carey J, Veitch A, Coltman DW. Detecting the signature of selection on immune genes in highly structured populations of wild sheep (Ovis dalli). Mol Ecol 2006; 15:623-37. [PMID: 16499690 DOI: 10.1111/j.1365-294x.2006.02829.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The confounding effects of population structure complicate efforts to identify regions of the genome under the influence of selection in natural populations. Here we test for evidence of selection in three genes involved in vertebrate immune function - the major histocompatibility complex (MHC), interferon gamma (IFNG) and natural resistance associated macrophage polymorphism (NRAMP) - in highly structured populations of wild thinhorn sheep (Ovis dalli). We examined patterns of variation at microsatellite loci linked to these gene regions and at the DNA sequence level. Simple Watterson's tests indicated balancing selection at all three gene regions. However, evidence for selection was confounded by population structure, as the Watterson's test statistics from linked markers were not outside of the range of values from unlinked and presumably neutral microsatellites. The translated coding sequences of thinhorn IFNG and NRAMP are fixed and identical to those of domestic sheep (Ovis aries). In contrast, the thinhorn MHC DRB locus shows significant evidence of overdominance through both an excess of nonsynonymous substitution and trans-species polymorphism. The failure to detect balancing selection at microsatellite loci linked to the MHC is likely the result of recombination between the markers and expressed gene regions.
Collapse
Affiliation(s)
- K Worley
- Department of Animal and Plant Sciences, University of Sheffield, UK.
| | | | | | | |
Collapse
|
23
|
Vychodilova-Krenkova L, Matiasovic J, Horin P. Single nucleotide polymorphisms in four functionally related immune response genes in the horse: CD14,TLR4, Ce, andFce R1 alpha. Int J Immunogenet 2005; 32:277-83. [PMID: 16164694 DOI: 10.1111/j.1744-313x.2005.00522.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The objective of this study was to identify single nucleotide polymorphisms (SNPs) within four functionally related immune response genes in the horse, and to develop genotyping techniques that could be useful for future genomic studies of horse infectious and allergic diseases. The genes analysed were: the lipopolysaccharide (LPS) receptor gene CD14, the toll-like receptor 4 gene TLR4, the gene Cepsilon encoding the IgE heavy chain molecule and the gene FcepsilonR1 alpha coding for the alpha subunit of the IgE receptor molecule. Horse-specific primers amplifying selected gene regions were designed and SNPs were searched by selective resequencing and/or by PCR-SSCP (polymerase chain reaction-sequence specific conformational polymorphism) or PCR-RFLP (PCR-restriction fragment length polymorphism). Gene expression was analysed by RT-PCR (reverse transcriptase-PCR) of all four genes examined. For CD14, the cDNA sequence was determined and a novel sequence of the 5'UTR region was identified. The protein-coding sequence was identical to that previously deposited in GenBank. 5'UTR, intronic and both synonymous and non-synonymous exonic SNPs were identified. Three SNPs were found in the CD14 gene, four in the TLR4 gene; two SNPs were identified in the Cepsilon gene, and one SNP was found in the FcepsilonR1 alpha gene. PCR-RFLP was developed for genotyping eight of the SNPs identified. The RT-PCR assay showed that all the SNPs reported here are parts of expressed genes. The results showed that important immunity-related genes in horses are polymorphic and that even non-synonymous SNPs with potential functional impact may occur. The methods developed for genotyping and haplotyping the SNPs identified represent, along with markers described previously, a potentially useful tool for genomic analysis of the function and role of these genes in immunity and in mechanisms of disease.
Collapse
Affiliation(s)
- L Vychodilova-Krenkova
- Institute of Animal Genetics, Faculty of Veterinary Medicine, Brno, 61242, Czech Republic
| | | | | |
Collapse
|