scholarly journals Differential Response of the Chicken Trachea to Chronic Infection with Virulent Mycoplasma gallisepticum Strain Ap3AS and Vaxsafe MG (Strain ts-304): a Transcriptional Profile

2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Sathya N. Kulappu Arachchige ◽  
Neil D. Young ◽  
Pollob K. Shil ◽  
Alistair R. Legione ◽  
Anna Kanci Condello ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Mycoplasma Gallisepticum ◽  
Chronic Respiratory Disease ◽  
Tracheal Mucosa ◽  
Content Type ◽  
Motor Movement ◽  
Cilia Formation ◽  
Junctional Complexes ◽  
Protein Classes ◽  
Gene Ontologies

ABSTRACT Mycoplasma gallisepticum is the primary etiological agent of chronic respiratory disease in chickens. Live attenuated vaccines are most commonly used in the field to control the disease, but current vaccines have some limitations. Vaxsafe MG (strain ts-304) is a new vaccine candidate that is efficacious at a lower dose than the current commercial vaccine strain ts-11, from which it is derived. In this study, the transcriptional profiles of the trachea of unvaccinated chickens and chickens vaccinated with strain ts-304 were compared 2 weeks after challenge with M. gallisepticum strain Ap3AS during the chronic stage of infection. After challenge, genes, gene ontologies, pathways, and protein classes involved in inflammation, cytokine production and signaling, and cell proliferation were upregulated, while those involved in formation and motor movement of cilia, formation of intercellular junctional complexes, and formation of the cytoskeleton were downregulated in the unvaccinated birds compared to the vaccinated birds, reflecting immune dysregulation and the pathological changes induced in the trachea by infection with M. gallisepticum. Vaccination appears to protect the structural and functional integrity of the tracheal mucosa 2 weeks after infection with M. gallisepticum.

scholarly journals Transcriptomic Analysis of Long-Term Protective Immunity Induced by Vaccination With Mycoplasma gallisepticum Strain ts-304

2021 ◽  
Vol 11 ◽  
Author(s):  
Sathya N. Kulappu Arachchige ◽  
Neil D. Young ◽  
Anna Kanci Condello ◽  
Oluwadamilola S. Omotainse ◽  
Amir H. Noormohammadi ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Cells ◽  
Mycoplasma Gallisepticum ◽  
Tracheal Mucosa ◽  
Chemokine Production ◽  
Live Attenuated Vaccine ◽  
Motor Movement ◽  
Transcriptional Changes ◽  
Protein Classes ◽  
Cellular Cytoskeleton

Live attenuated vaccines are commonly used to control Mycoplasma gallisepticum infections in chickens. M. gallisepticum ts-304 is a novel live attenuated vaccine strain that has been shown to be safe and effective. In this study, the transcriptional profiles of genes in the tracheal mucosa in chickens challenged with the M. gallisepticum wild-type strain Ap3AS at 57 weeks after vaccination with ts-304 were explored and compared with the profiles of unvaccinated chickens that had been challenged with strain Ap3AS, unvaccinated and unchallenged chickens, and vaccinated but unchallenged chickens. At two weeks after challenge, pair-wise comparisons of transcription in vaccinated-only, vaccinated-and-challenged and unvaccinated and unchallenged birds detected no differences. However, the challenged-only birds had significant up-regulation in the transcription of genes and enrichment of gene ontologies, pathways and protein classes involved in infiltration and proliferation of inflammatory cells and immune responses mediated through enhanced cytokine and chemokine production and signaling, while those predicted to be involved in formation and motor movement of cilia and formation of the cellular cytoskeleton were significantly down-regulated. The transcriptional changes associated with the inflammatory response were less severe in these mature birds than in the relatively young birds examined in a previous study. The findings of this study demonstrated that vaccination with the attenuated M. gallisepticum strain ts-304 protects against the transcriptional changes associated with the inflammatory response and pathological changes in the tracheal mucosa caused by infection with M. gallisepticum in chickens for at least 57 weeks after vaccination.

scholarly journals Role of the GapA and CrmA Cytadhesins of Mycoplasma gallisepticum in Promoting Virulence and Host Colonization

2013 ◽  
Vol 81 (5) ◽  
pp. 1618-1624 ◽  
Author(s):  
Ivana Indiková ◽  
Peter Much ◽  
László Stipkovits ◽  
Karin Siebert-Gulle ◽  
Michael P. Szostak ◽  
...  
Keyword(s):  
Point Mutation ◽  
Mycoplasma Gallisepticum ◽  
Chronic Respiratory Disease ◽  
Host Colonization ◽  
Content Type ◽  
Inner Organs ◽  
Avian Pathogen ◽  
Low Passage

ABSTRACTMycoplasma gallisepticumis an important avian pathogen that commonly induces chronic respiratory disease in chicken. To better understand the mycoplasma factors involved in host colonization, chickens were infected via aerosol with two hemadsorption-negative (HA−) mutants, mHAD3 and RCL2, that were derived from a low passage of the pathogenic strain R (Rlow) and are both deficient in the two major cytadhesins GapA and CrmA. After 9 days of infection, chickens were monitored for air sac lesions and for the presence of mycoplasmas in various organs. The data showed that mHAD3, in which thecrmAgene has been disrupted, did not promote efficient colonization or significant air sac lesions. In contrast, the spontaneous HA−RCL2 mutant, which contains a point mutation in thegapAstructural gene, successfully colonized the respiratory tract and displayed an attenuated virulence compared to that of Rlow. It has previously been shownin vitrothat the point mutation of RCL2 spontaneously reverts with a high frequency, resulting in on-and-off switching of the HA phenotype. Detailed analyses further revealed that such an event is not responsible for the observedin vivooutcome, since 98.4% of the mycoplasma populations recovered from RCL2-infected chickens still display the mutation and the associated phenotype. Unlike Rlow, however, RCL2 was unable to colonize inner organs. These findings demonstrate the major role played by the GapA and CrmA proteins inM. gallisepticumhost colonization and virulence.

scholarly journals Transcriptional Profiling of the Chicken Tracheal Response to Virulent Mycoplasma gallisepticum Strain Rlow

2017 ◽  
Vol 85 (10) ◽  
Author(s):  
J. Beaudet ◽  
E. R. Tulman ◽  
K. Pflaum ◽  
X. Liao ◽  
G. F. Kutish ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Virulent Strain ◽  
Current Model ◽  
Inflammatory Cells ◽  
Mycoplasma Gallisepticum ◽  
Immune Dysregulation ◽  
Mitogen Activated Protein Kinase ◽  
Tracheal Mucosa ◽  
Content Type

ABSTRACT Mycoplasma gallisepticum, the primary etiologic agent of chronic respiratory disease (CRD) in poultry, leads to prolonged recruitment and activation of inflammatory cells in the respiratory mucosa. This is consistent with the current model of immune dysregulation that ostensibly allows the organism to evade clearance mechanisms and establish chronic infection. To date, studies using quantitative reverse transcription-PCR (qRT-PCR) and microarrays have shown a significant transient upregulation of cytokines and chemokines from tracheal epithelial cells (TECs) in vitro and tracheal tissue ex vivo in response to virulent strain Rlow that contributes to the infiltration of inflammatory cells into the tracheal mucosa. To expand upon these experiments, RNA was isolated from tracheas of 20 chickens infected with M. gallisepticum Rlow and 20 mock-infected animals at days 1, 3, 5, and 7 postinoculation, and samples were analyzed for differential gene expression using Illumina RNA sequencing. A rapid host response was observed 24 h postinfection, with over 2,500 significantly differentially expressed genes on day 3, the peak of infection. Many of these genes have immune-related functions involved in signaling pathways, including Toll-like receptor (TLR), mitogen-activated protein kinase, Jak-STAT, and the nucleotide oligomerization domain-like receptor pathways. Of interest was the increased expression of numerous cell surface receptors, including TLR4 and TLR15, which may contribute to the production of cytokines. Metabolic pathways were also activated on days 1 and 3 postinfection, ostensibly due to epithelial cell distress that occurs upon infection. Early perturbations in tissue-wide gene expression, as observed here, may underpin a profound immune dysregulation, setting the stage for disease manifestations characteristic of M. gallisepticum infection.

scholarly journals Global Changes in Mycoplasma gallisepticum Phase-Variable Lipoprotein GenevlhAExpression duringIn VivoInfection of the Natural Chicken Host

2015 ◽  
Vol 84 (1) ◽  
pp. 351-355 ◽  
Author(s):  
K. Pflaum ◽  
E. R. Tulman ◽  
J. Beaudet ◽  
X. Liao ◽  
S. J. Geary
Keyword(s):  
Gene Expression ◽  
Phase Variation ◽  
Mycoplasma Gallisepticum ◽  
Chronic Respiratory Disease ◽  
Etiologic Agent ◽  
Economic Losses ◽  
Global Changes ◽  
Phase Variable ◽  
Content Type ◽  
Host Interaction

Mycoplasma gallisepticumis the primary etiologic agent of chronic respiratory disease in poultry, a disease largely affecting the respiratory tract and causing significant economic losses worldwide. Immunodominant proteins encoded by members of the variable lipoprotein and hemagglutinin (vlhA) gene family are thought to be important for mechanisms ofM. gallisepticum-host interaction, pathogenesis, and immune evasion, but their exact role and the overall nature of their phase variation are unknown. To better understand these mechanisms, we assessed global transcriptomicvlhAgene expression directly fromM. gallisepticumpopulations present on tracheal mucosae during a 7-day experimental infection in the natural chicken host. Here we report differences in both dominant and minorvlhAgene expression levels throughout the first week of infection and starting as early as day 1 postinfection, consistent with a functional role not dependent on adaptive immunity for driving phase variation. Notably, data indicated that, at given time points, specificvlhAgenes were similarly dominant in multiple independent hosts, suggesting a nonstochastic temporal progression of dominantvlhAgene expression in the colonizing bacterial population. The dominant expression of a givenvlhAgene was not dependent on the presence of 12-copy GAA trinucleotide repeats in the promoter region and did not revert to the predominatevlhAgene when no longer faced with host pressures. Overall, these data indicate thatvlhAphase variation is dynamic throughout the earliest stages of infection and that the pattern of dominantvlhAexpression may be nonrandom and regulated by previously unrecognized mechanisms.

scholarly journals Study on the Mechanism of Injury of Chicken Tracheal Epithelium Caused by Mycoplasma Gallisepticum Infection

2021 ◽  
Author(s):  
Chunlin WU ◽  
Lemiao Zhong ◽  
Ligen Zhang ◽  
Wenji Li ◽  
Binhui Liu ◽  
...  
Keyword(s):  
Immunohistochemical Analysis ◽  
Mycoplasma Gallisepticum ◽  
Chronic Respiratory Disease ◽  
Immune Defense ◽  
Sequencing Analysis ◽  
Tracheal Mucosa ◽  
Respiratory Epithelial Cells ◽  
Epithelial Injury ◽  
Junction Protein ◽  
Respiratory Epithelial

Abstract Mycoplasma gallisepticum (MG) is a pathogenic microorganism that is seriously harmful to the poultry industry. It mainly adsorbs on the cilia and mucosa of respiratory epithelial cells, resulting in tracheal mucosal epithelial injury or ciliary shedding, causing chronic respiratory disease (CRD). In order to study the damage of tracheal mucosal epithelium induced by MG infection in chickens and explore its possible mechanism, SPF chicks were challenged with the wild-type Mycoplasma gallisepticum strain MG-HY strain. Then, transcriptome sequencing analysis was performed to study the mechanism of MG tracheal mucosal epithelial injury. During infection, MG localizes and proliferates in the chicken trachea, and induces mucosal epithelial damage.A total of 3112 significantly (P < 0.01) differentially expressed genes (DEGs) were selected by RNA-seq, including 1646 up-regulated genes and 1466 down-regulated genes. Functional analysis showed increased expression levels of genes involved in immune defense response and mechanical barrier of tracheal mucosa in infected chicks. The expression level of pro-inflammatory cytokines (TNF-α) increased, activating the upstream protein Ras of the ERK-MLCK signaling pathway, Ras causing ERK1/2 phosphorylation levels to rise and MLCK activation, thus causing phosphationalization of MLC, and further regulating the expression and mucous distribution of tight junction protein (TJ), leading to tracheal mucosal epithelial injury in chicks. The results of qRT-PCR assay and immunohistochemical analysis were consistent with the results of transcriptome analysis. Overall, our results provide a basis for further investigation of the mechanisms underlying the epithelial damage of the tracheal membrane in chicks caused by MG-infection, contributing to the understanding of how MG affects avian respiratory diseases.

scholarly journals Up-Regulation of miR-130b-3p Activates the PTEN/PI3K/AKT/NF-κB Pathway to Defense against Mycoplasma gallisepticum (HS Strain) Infection of Chicken

2018 ◽  
Vol 19 (8) ◽  
pp. 2172 ◽  
Author(s):  
Bo Yuan ◽  
Mengyun Zou ◽  
Yabo Zhao ◽  
Kang Zhang ◽  
Yingfei Sun ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Chicken Embryo ◽  
Mycoplasma Gallisepticum ◽  
Nuclear Factor Κb ◽  
Chronic Respiratory Disease ◽  
Luciferase Reporter ◽  
Sequencing Data ◽  
Infected Chicken ◽  
Functional Studies

Mycoplasma gallisepticum (MG) is the pathogen of chronic respiratory disease (CRD), hallmarked by vigorous inflammation in chickens, causing the poultry industry enormous losses. miRNAs have emerged as important regulators of animal diseases. Previous miRNA sequencing data has demonstrated that miR-130b-3p is up-regulated in MG-infected chicken embryo lungs. Therefore, we aimed to investigate the function of miR-130b-3p in MG infection of chickens. RT-qPCR results confirmed that miR-130b-3p was up-regulated both in MG-infected chicken embryo lungs and chicken embryonic fibroblast cells (DF-1 cells). Furthermore, functional studies showed that overexpression of miR-130b-3p promoted MG-infected DF-1 cell proliferation and cell cycle, whereas inhibition of miR-130b-3p weakened these cellular processes. Luciferase reporter assay combined with gene expression data supported that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was a direct target of miR-130b-3p. Additionally, overexpression of miR-130b-3p resulted in up-regulations of phosphatidylinositol-3 kinase (PI3K), serine/threonine kinase (AKT), and nuclear factor-κB (NF-κB), whereas inhibition of miR-130b-3p led to the opposite results. Altogether, upon MG infection, up-regulation of miR-130b-3p activates the PI3K/AKT/NF-κB pathway, facilitates cell proliferation and cell cycle via down-regulating PTEN. This study helps to understand the mechanism of host response to MG infection.

scholarly journals Variable Lipoprotein Hemagglutinin A Gene (vlhA) Expression in VariantMycoplasmagallisepticumStrainsIn Vivo

2018 ◽  
Vol 86 (11) ◽  
Author(s):  
K. Pflaum ◽  
E. R. Tulman ◽  
J. Beaudet ◽  
J. Canter ◽  
S. J. Geary
Keyword(s):  
Gene Family ◽  
No Reduction ◽  
Phase Variation ◽  
Chronic Respiratory Disease ◽  
Etiologic Agent ◽  
Economic Losses ◽  
Wild Type ◽  
Exact Role ◽  
Content Type ◽  
Host Interaction

ABSTRACTMycoplasma gallisepticum, the primary etiologic agent of chronic respiratory disease, is a significant poultry pathogen, causing severe inflammation and leading to economic losses worldwide. Immunodominant proteins encoded by the variable lipoprotein and hemagglutinin (vlhA) gene family are thought to be important forM. gallisepticum-host interaction, pathogenesis, and immune evasion, but their exact role remains unknown. Previous work has demonstrated thatvlhAphase variation is dynamic throughout the earliest stages of infection, withvlhA3.03 being the predominantvlhAexpressed during the initial infection, and that the pattern of dominantvlhAexpression may be nonrandom and regulated by previously unrecognized mechanisms. To further investigate this gene family, we assessed thevlhAprofile of two well-characterized vaccine strains, GT5 and Mg7, avlhA3.03 mutant strain, and anM. gallisepticumpopulation expressing an alternative immunodominantvlhA. Here, we report that twoM. gallisepticumvaccine strains show differentvlhAprofiles over the first 2 days of infection compared to that of wild-type Rlow, while the population expressing an alternative immunodominantvlhAgene reverted to a profile indistinguishable from that of wild-type Rlow. Additionally, we observed a slight shift in thevlhAgene expression profile but no reduction in virulence in avlhA3.03 mutant. Taken together, these data further support the hypothesis thatM. gallisepticum vlhAgenes change in a nonstochastic temporal progression of expression and thatvlhA3.03, while preferred, is not required for virulence. Collectively, these data may be important in elucidating mechanisms of colonization and overall pathogenesis ofM. gallisepticum.

scholarly journals Hydrogen Peroxide Production from Glycerol Metabolism Is Dispensable for Virulence of Mycoplasma gallisepticum in the Tracheas of Chickens

2014 ◽  
Vol 82 (12) ◽  
pp. 4915-4920 ◽  
Author(s):  
S. M. Szczepanek ◽  
M. Boccaccio ◽  
K. Pflaum ◽  
X. Liao ◽  
S. J. Geary
Keyword(s):  
Hydrogen Peroxide ◽  
Mycoplasma Gallisepticum ◽  
Eukaryotic Cells ◽  
Glycerol Metabolism ◽  
Content Type ◽  
Avian Pathogen ◽  
Mucosal Thickness ◽  
Transposon Mutants ◽  
Utilization Pathway

ABSTRACTHydrogen peroxide (H2O2) is a by-product of glycerol metabolism in mycoplasmas and has been shown to cause cytotoxicity for cocultured eukaryotic cells. There appears to be selective pressure for mycoplasmas to retain the genes needed for glycerol metabolism. This has generated interest and speculation as to their function during infection. However, the actual effects of glycerol metabolism and H2O2production on virulencein vivohave never been assessed in anyMycoplasmaspecies. To this end, we determined that the wild-type (WT) Rlowstrain of the avian pathogenMycoplasma gallisepticumis capable of producing H2O2when grown in glycerol and is cytotoxic to eukaryotic cells in culture. Transposon mutants with mutations in the genes present in the glycerol transport and utilization pathway, namely,glpO,glpK, andglpF, were identified. All mutants assessed were incapable of producing H2O2and were not cytotoxic when grown in glycerol. We also determined that vaccine strains ts-11 and 6/85 produce little to no H2O2when grown in glycerol, while the naturally attenuated F strain does produce H2O2. Chickens were infected with one of twoglpOmutants, aglpKmutant, Rlow, or growth medium, and tracheal mucosal thickness and lesion scores were assessed. Interestingly, allglpmutants were reproducibly virulent in the respiratory tracts of the chickens. Thus, there appears to be no link between glycerol metabolism/H2O2production/cytotoxicity and virulence for thisMycoplasmaspecies in its natural host. However, it is possible that glycerol metabolism is required byM. gallisepticumin a niche that we have yet to study.

scholarly journals Phenotypic Switching in Mycoplasma gallisepticum Hemadsorption Is Governed by a High-Frequency, Reversible Point Mutation

2003 ◽  
Vol 71 (3) ◽  
pp. 1265-1273 ◽  
Author(s):  
Florian Winner ◽  
Ivana Markovà ◽  
Peter Much ◽  
Albin Lugmair ◽  
Karin Siebert-Gulle ◽  
...  
Keyword(s):  
High Frequency ◽  
Stop Codon ◽  
Phase Variation ◽  
Mycoplasma Gallisepticum ◽  
Chronic Respiratory Disease ◽  
Transcription Unit ◽  
Phenotypic Switching ◽  
Base Substitution ◽  
Mutational Event ◽  
Repeated Motifs

ABSTRACT Mycoplasma gallisepticum is a flask-shaped organism that commonly induces chronic respiratory disease in chickens and infectious sinusitis in turkeys. Phenotypic switching in M. gallisepticum hemadsorption (HA) was found to correlate with phase variation of the GapA cytadhesin concurrently with that of the CrmA protein, which exhibits cytadhesin-related features and is encoded by a gene located downstream of the gapA gene as part of the same transcription unit. In clones derived from strain Rlow, detailed genetic analyses further revealed that on-off switching in GapA expression is governed by a reversible base substitution occurring at the beginning of the gapA structural gene. In HA− variants, this event generates a stop codon that results in the premature termination of GapA translation and consequently affects the expression of CrmA. Sequences flanking the mutation spot do not feature any repeated motifs that could account for error-prone mutation via DNA slippage and the exact mechanism underlying this high-frequency mutational event remains to be elucidated. An HA− mutant deficient in producing CrmA, mHAD3, was obtained by disrupting the crmA gene by using transposition mutagenesis. Despite a fully functional gapA gene, the amount of GapA detected in this mutant was considerably lower than in HA+ clonal variants, suggesting that, in absence of CrmA, GapA might be subjected to a higher turnover.

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