scholarly journals IP-10 Is a Sensitive Biomarker of Antigen Recognition in Whole-Blood Stimulation Assays Used for the Diagnosis of Mycobacterium bovis Infection in African Buffaloes (Syncerus caffer)

2015 ◽  
Vol 22 (8) ◽  
pp. 974-978 ◽  
Author(s):  
Wynand J. Goosen ◽  
David Cooper ◽  
Michele A. Miller ◽  
Paul D. van Helden ◽  
Sven D. C. Parsons
Keyword(s):  
Mycobacterium Bovis ◽  
Interferon Gamma ◽  
Whole Blood ◽  
Characteristic Curve ◽  
Antigen Recognition ◽  
Syncerus Caffer ◽  
Content Type ◽  
Domestic Species ◽  
Wide Range ◽  
Ifn Γ

ABSTRACTAfrican buffaloes (Syncerus caffer) are maintenance hosts ofMycobacterium bovis, the causative agent of bovine tuberculosis. They act as reservoirs of this infection for a wide range of wildlife and domestic species, and the detection of infected animals is important to control the geographic spread and transmission of the disease. Interferon gamma (IFN-γ) release assays (IGRAs) utilizing pathogen-derived peptide antigens are highly specific tests ofM. bovisinfection; however, the diagnostic sensitivities of these assays are suboptimal. We evaluated the diagnostic utility of measuring antigen-dependent interferon gamma-induced protein 10 (IP-10) release as an alternative to measuring IFN-γ levels.M. bovis-exposed buffaloes were tested using the Bovigam PC-EC and Bovigam PC-HP assays and a modified QuantiFERON TB-Gold (mQFT) assay. IP-10 was measured in the harvested plasma and was produced in significantly greater abundance in response toM. bovisantigens in Bovigam-positive than in Bovigam-negative animals. For each assay, using the Bovigam results as a reference, receiver operating characteristic curve analysis was done to determine diagnostically relevant cutoff values for IP-10. Thereafter, mQFT test results derived from measurement of IP-10 and IFN-γ were compared and a larger number of Bovigam-positive animals were detected using IP-10 as a diagnostic marker. Moreover, using IP-10, agreement between the mQFT assay and the Bovigam assays was increased, while the excellent agreement between the Bovigam assays was retained. We conclude that IP-10 is a sensitive marker of antigen recognition and that measurement of this cytokine in antigen-stimulated whole blood might increase the sensitivity of conventional IGRAs in African buffaloes.

scholarly journals Stimulation of Bovine Whole-Blood Samples Cultured in Media Supplemented with Recombinant Interleukin-7 (IL-7) and IL-12 Extends the Life Span of the Gamma Interferon Assay To Detect Mycobacterium bovis-Infected Cattle

2016 ◽  
Vol 54 (9) ◽  
pp. 2315-2320 ◽  
Author(s):  
E. Gerace ◽  
P. Pasquali ◽  
B. Oesch ◽  
M. Falduto ◽  
F. Mandanici ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Whole Blood ◽  
Gamma Interferon ◽  
Infected Cattle ◽  
Blood Samples ◽  
Content Type ◽  
Rpmi Medium ◽  
Interleukin 7 ◽  
Ifn Γ ◽  
Whole Blood Samples

The gamma interferon (IFN-γ) assay is widely used to measure cell-mediated immune (CMI) response for the early detection of tuberculosis infection. Processing whole-blood samples for CMI-based diagnostics is time sensitive and usually must occur within 8 h of collection to ensure optimal assay performance. In this study, we developed and tested a modified protocol, in which whole-blood samples fromMycobacterium bovis-infected cattle were diluted 1:1 in RPMI medium containing 0.3% fetal bovine serum (FBS) added or not to recombinant mouse interleukin-7 (rmIL-7) or rmIL-12, alone or in combination, and stored at 4°C. At 3 and 6 days postcollection, the diluted blood samples were adjusted to 10% FBS, dispensed into culture trays, stimulated with a bovine purified protein derivative fromM. bovis, and incubated at 37°C in 5% CO2in air. Plasma was removed and assayed for an IFN-γ response using bovine IFN-γ enzyme-linked immunosorbent assay (ELISA) (Bovigam). The results were then compared with those obtained from the conventional procedure. The IFN-γ responses of the samples stored up to 6 days postcollection in the supplemented RPMI medium were similar to those observed in the samples processed within 8 h after sampling, indicating that lymphocyte vitality and response were preserved. The addition of rmIL-7 and rmIL-12, alone or in combination, to culture medium can enhance lymphocyte survival and thus extends the time limit within which the IFN-γ assay can be applied as a diagnostic tool in bovine tuberculosis surveillance and eradication.

scholarly journals New Recombinant Mycobacterium bovis BCG Expression Vectors: Improving Genetic Control over Mycobacterial Promoters

2016 ◽  
Vol 82 (8) ◽  
pp. 2240-2246 ◽  
Author(s):  
Alex I. Kanno ◽  
Cibelly Goulart ◽  
Henrique K. Rofatto ◽  
Sergio C. Oliveira ◽  
Luciana C. C. Leite ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Fluorescent Protein ◽  
Vaccine Development ◽  
Expression Vectors ◽  
Content Type ◽  
Expression Levels ◽  
Wide Range ◽  
Mycobacteriophage L5 ◽  
Green Fluorescent ◽  
Selection Of

ABSTRACTThe expression of many antigens, stimulatory molecules, or even metabolic pathways in mycobacteria such asMycobacterium bovisBCG orM. smegmatiswas made possible through the development of shuttle vectors, and several recombinant vaccines have been constructed. However, gene expression in any of these systems relied mostly on the selection of natural promoters expected to provide the required level of expression by trial and error. To establish a systematic selection of promoters with a range of strengths, we generated a library of mutagenized promoters through error-prone PCR of the strong PL5promoter, originally from mycobacteriophage L5. These promoters were cloned upstream of the enhanced green fluorescent protein reporter gene, and recombinantM. smegmatisbacteria exhibiting a wide range of fluorescence levels were identified. A set of promoters was selected and identified as having high (pJK-F8), intermediate (pJK-B7, pJK-E6, pJK-D6), or low (pJK-C1) promoter strengths in bothM. smegmatisandM. bovisBCG. The sequencing of the promoter region demonstrated that it was extensively modified (6 to 11%) in all of the plasmids selected. To test the functionality of the system, two different expression vectors were demonstrated to allow corresponding expression levels of theSchistosoma mansoniantigen Sm29 in BCG. The approach used here can be used to adjust expression levels for synthetic and/or systems biology studies or for vaccine development to maximize the immune response.

scholarly journals Immediate Interferon Gamma Induction Determines Murine Host Compatibility Differences between Toxoplasma gondii and Neospora caninum

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Rachel S. Coombs ◽  
Matthew L. Blank ◽  
Elizabeth D. English ◽  
Yaw Adomako-Ankomah ◽  
Ifeanyi-Chukwu Samuel Urama ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Interferon Gamma ◽  
Neospora Caninum ◽  
Ectopic Expression ◽  
Parasite Burden ◽  
Interleukin 12 ◽  
Content Type ◽  
Ifn Γ ◽  
And Control

ABSTRACT Rodents are critical for the transmission of Toxoplasma gondii to the definitive feline host via predation, and this relationship has been extensively studied as a model for immune responses to parasites. Neospora caninum is a closely related coccidian parasite of ruminants and canines but is not naturally transmitted by rodents. We compared mouse innate immune responses to N. caninum and T. gondii and found marked differences in cytokine levels and parasite growth kinetics during the first 24 h postinfection (hpi). N. caninum-infected mice produced significantly higher levels of interleukin-12 (IL-12) and interferon gamma (IFN-γ) by as early as 4 hpi, but the level of IFN-γ was significantly lower or undetectable in T. gondii-infected mice during the first 24 hpi. “Immediate” IFN-γ and IL-12p40 production was not detected in MyD88−/− mice. However, unlike IL-12p40−/− and IFN-γ−/− mice, MyD88−/− mice survived N. caninum infections at the dose used in this study. Serial measures of parasite burden showed that MyD88−/− mice were more susceptible to N. caninum infections than wild-type (WT) mice, and control of parasite burdens correlated with a pulse of serum IFN-γ at 3 to 4 days postinfection in the absence of detectable IL-12. Immediate IFN-γ was partially dependent on the T. gondii mouse profilin receptor Toll-like receptor 11 (TLR11), but the ectopic expression of N. caninum profilin in T. gondii had no impact on early IFN-γ production or parasite proliferation. Our data indicate that T. gondii is capable of evading host detection during the first hours after infection, while N. caninum is not, and this is likely due to the early MyD88-dependent recognition of ligands other than profilin.

scholarly journals Population Structure of Mycobacterium bovis in Germany: a Long-Term Study Using Whole-Genome Sequencing Combined with Conventional Molecular Typing Methods

2020 ◽  
Vol 58 (11) ◽  
Author(s):  
Thomas A. Kohl ◽  
Katharina Kranzer ◽  
Sönke Andres ◽  
Thierry Wirth ◽  
Stefan Niemann ◽  
...  
Keyword(s):  
Population Structure ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Mycobacterium Bovis ◽  
Variable Number Tandem Repeat ◽  
Epidemiological Surveillance ◽  
Whole Genome ◽  
Content Type ◽  
Long Term Study ◽  
Wide Range

ABSTRACT Mycobacterium bovis is the primary cause of bovine tuberculosis (bTB) and infects a wide range of domestic animal and wildlife species and humans. In Germany, bTB still emerges sporadically in cattle herds, free-ranging wildlife, diverse captive animal species, and humans. In order to understand the underlying population structure and estimate the population size fluctuation through time, we analyzed 131 M. bovis strains from animals (n = 38) and humans (n = 93) in Germany from 1999 to 2017 by whole-genome sequencing (WGS), mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, and spoligotyping. Based on WGS data analysis, 122 out of the 131 M. bovis strains were classified into 13 major clades, of which 6 contained strains from both human and animal cases and 7 only strains from human cases. Bayesian analyses suggest that the M. bovis population went through two sharp anticlimaxes, one in the middle of the 18th century and another one in the 1950s. WGS-based cluster analysis grouped 46 strains into 13 clusters ranging in size from 2 to 11 members and involving strains from distinct host types, e.g., only cattle and also mixed hosts. Animal strains of four clusters were obtained over a 9-year span, pointing toward autochthonous persistent bTB infection cycles. As expected, WGS had a higher discriminatory power than spoligotyping and MIRU-VNTR typing. In conclusion, our data confirm that WGS and suitable bioinformatics constitute the method of choice to implement prospective molecular epidemiological surveillance of M. bovis. The population of M. bovis in Germany is diverse, with subtle, but existing, interactions between different host groups.

scholarly journals Clinical and bacteriological correlates of whole blood interferon gamma (IFN-γ) in newly detected cases of pulmonary TB

2010 ◽  
Vol 3 (3) ◽  
pp. 224-231 ◽  
Author(s):  
M Bandyopadhyay ◽  
A Bhakta ◽  
S Chakrabarty ◽  
M Pal ◽  
P Bharati
Keyword(s):  
Interferon Gamma ◽  
Whole Blood ◽  
Pulmonary Tb ◽  
Ifn Γ

scholarly journals Tuberculin Skin Testing Boosts Interferon Gamma Responses to DIVA Reagents in Mycobacterium bovis-Infected Cattle

2017 ◽  
Vol 24 (5) ◽  
Author(s):  
Gareth J. Jones ◽  
Mick Coad ◽  
Bhagwati Khatri ◽  
Javier Bezos ◽  
Natalie A. Parlane ◽  
...  
Keyword(s):  
Skin Test ◽  
Mycobacterium Bovis ◽  
Interferon Gamma ◽  
Skin Testing ◽  
Interferon Response ◽  
Tuberculin Skin Testing ◽  
Test Scenario ◽  
Positive Skin ◽  
Content Type ◽  
Bcg Vaccination

ABSTRACT Mycobacterium bovis BCG vaccination sensitizes cattle to bovine tuberculin, which compromises the use of the current bovine tuberculosis (TB) surveillance tests. Although the performance of a blood test (that utilizes antigens expressed by Mycobacterium bovis but not by BCG) capable of discriminating infected from vaccinated animals (DIVA interferon gamma test [DIT]) has been evaluated in naturally infected TB field reactors, there is a need to perform similar analysis in a BCG-vaccinated M. bovis-infected population. Furthermore, we explored different scenarios under which a DIT may be implemented alongside BCG vaccination: (i) serial testing to resolve potential false-positive skin test results or (ii) a standalone test to replace the single intradermal comparative cervical tuberculin (SICCT) skin test. Our results demonstrated significantly better relative test sensitivity when the DIT was evaluated in a serial test scenario. Direct comparison of pre- and post-skin test blood samples revealed that the SICCT test induced significant boosting of the gamma interferon response in M. bovis-infected animals to both the ESAT-6–CFP-10 and Rv3615c peptide cocktails that comprise the DIT, which persisted for the ESAT-6–CFP-10 reagent for at least 14 days. Importantly, no similar boosting effects were observed in noninfected BCG vaccinates, suggesting that DIVA blood testing after a recent skin test would have minimal impact on test specificity.

scholarly journals Interaction of Interferon Gamma-Induced Reactive Oxygen Species with Ceftazidime Leads to Synergistic Killing of Intracellular Burkholderia pseudomallei

2014 ◽  
Vol 58 (10) ◽  
pp. 5954-5963 ◽  
Author(s):  
Kara Mosovsky ◽  
Ediane Silva ◽  
Ryan Troyer ◽  
Katie Propst-Graham ◽  
Steven Dow
Keyword(s):  
Reactive Oxygen Species ◽  
Interferon Gamma ◽  
Burkholderia Pseudomallei ◽  
Actin Polymerization ◽  
Reactive Oxygen ◽  
Buthionine Sulfoximine ◽  
Oxygen Species ◽  
Intracellular Killing ◽  
Content Type ◽  
Ifn Γ

ABSTRACTBurkholderia pseudomallei, a facultative intracellular pathogen, causes severe infections and is inherently refractory to many antibiotics. Previous studies from our group have shown that interferon gamma (IFN-γ) interacts synergistically with the antibiotic ceftazidime to kill bacteria in infected macrophages. The present study aimed to identify the underlying mechanism of that interaction. We first showed that blocking reactive oxygen species (ROS) pathways reversed IFN-γ- and ceftazidime-mediated killing, which led to our hypothesis that IFN-γ-induced ROS interacted with ceftazidime to synergistically killBurkholderiabacteria. Consistent with this hypothesis, we also observed that buthionine sulfoximine (BSO), another inducer of ROS, could substitute for IFN-γ to similarly potentiate the effect of ceftazidime on intracellular killing. Next, we observed that IFN-γ induced ROS-mediated killing of intracellular but not extracellular bacteria. On the other hand, ceftazidime effectively reduced extracellular bacteria but was not capable of intracellular killing when applied at 10 μg/ml. We investigated the exact role of IFN-γ-induced ROS responses on intracellular bacteria and notably observed a lack of actin polymerization associated withBurkholderiabacteria in IFN-γ-treated macrophages, which led to our finding that IFN-γ-induced ROS blocks vacuolar escape. Based on these results, we propose a model in which synergistically reduced bacterial burden is achieved primarily through separate and compartmentalized killing: intracellular killing by IFN-γ-induced ROS responses and extracellular killing by ceftazidime. Our findings suggest a means of enhancing antibiotic activity againstBurkholderiabacteria through combination with drugs that induce ROS pathways or otherwise target intracellular spread and/or replication of bacteria.

scholarly journals Characterization of Chlamydial Rho and the Role of Rho-Mediated Transcriptional Polarity during Interferon Gamma-Mediated Tryptophan Limitation

2018 ◽  
Vol 86 (7) ◽  
Author(s):  
Scot P. Ouellette ◽  
Parker R. Messerli ◽  
Nicholas A. Wood ◽  
Heather Hajovsky
Keyword(s):  
Interferon Gamma ◽  
Stringent Response ◽  
Transcript Abundance ◽  
Developmentally Regulated ◽  
Content Type ◽  
Infected Cells ◽  
Ifn Γ ◽  
The Stability ◽  
Large Genes

ABSTRACTAs an obligate intracellular, developmentally regulated bacterium,Chlamydiais sensitive to amino acid fluctuations within its host cell. When human epithelial cells are treated with the cytokine interferon gamma (IFN-γ), the tryptophan (Trp)-degrading enzyme, indoleamine-2,3-dioxygenase, is induced. Chlamydiae within such cells are starved for Trp and enter a state of so-called persistence.Chlamydialacks the stringent response used by many eubacteria to respond to this stress. Unusually, chlamydial transcription is globally elevated during Trp starvation with transcripts for Trp codon-containing genes disproportionately increased. Yet, the presence of Trp codons destabilized 3′ ends of transcripts in operons or large genes. We initially hypothesized that ribosome stalling on Trp codons rendered the 3′ ends sensitive to RNase activity. The half-life of chlamydial transcripts containing different numbers of Trp codons was thus measured in untreated and IFN-γ-treated infected cells to determine whether Trp codons influenced the stability of transcripts. However, no effect of Trp codon content was detected. Therefore, we investigated whether Rho-dependent transcription termination could play a role in mediating transcript instability. Rho is expressed as a midcycle gene product, interacts with itself as predicted, and is present in all chlamydial species. Inhibition of Rho via the Rho-specific antibiotic, bicyclomycin, and overexpression of Rho are detrimental to chlamydiae. Finally, when we measured transcript abundance 3′ to Trp codons in the presence of bicyclomycin, we observed that transcript abundance increased. These data are the first to demonstrate the importance of Rho inChlamydiaand the role of Rho-dependent transcription polarity during persistence.

scholarly journals Listeria-Vectored Vaccine Expressing the Mycobacterium tuberculosis 30-Kilodalton Major Secretory Protein via the Constitutively Active prfA* Regulon Boosts Mycobacterium bovis BCG Efficacy against Tuberculosis

2017 ◽  
Vol 85 (9) ◽  
Author(s):  
Qingmei Jia ◽  
Barbara Jane Dillon ◽  
Saša Masleša-Galić ◽  
Marcus A. Horwitz
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Bovis ◽  
Interleukin 2 ◽  
Secretory Protein ◽  
Broth Culture ◽  
Listeriolysin O ◽  
Content Type ◽  
Ifn Γ ◽  
Constitutively Active

ABSTRACT A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective Mycobacterium bovis BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis 30-kDa major secretory protein (r30/antigen 85B [Ag85B]) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated L. monocytogenes vectors, L. monocytogenes ΔactA (LmI), L. monocytogenes ΔactA ΔinlB (LmII), and L. monocytogenes ΔactA ΔinlB prfA* (LmIII), we constructed five rLm30 vaccine candidates expressing r30 linked in frame to the L. monocytogenes listeriolysin O signal sequence and driven by the hly promoter (h30) or linked in frame to the ActA N-terminal 100 amino acids and driven by the actA promoter (a30). All five rLm30 vaccines secreted r30 in broth and macrophages; while rLm30 expressing r30 via a constitutively active prfA* regulon (rLmIII/a30) expressed the largest amount of r30 in broth culture, all five rLm30 vaccines expressed equivalent amounts of r30 in infected macrophages. In comparative studies, boosting of BCG-immunized mice with rLmIII/a30 induced the strongest antigen-specific T-cell responses, including splenic and lung polyfunctional CD4+ T cells expressing the three cytokines interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-2 (IL-2) (P < 0.001) and splenic and lung CD8+ T cells expressing IFN-γ (P < 0.0001). In mice and guinea pigs, the rLmIII/a30 and rLmI/h30 vaccines were generally more potent booster vaccines than r30 with an adjuvant and a recombinant adenovirus vaccine expressing r30. In a setting in which BCG alone was highly immunoprotective, boosting of mice with rLmIII/a30, the most potent of the vaccines, significantly enhanced protection against aerosolized M. tuberculosis (P < 0.01).

scholarly journals Evaluation of Gamma Interferon (IFN-γ)-Induced Protein 10 Responses for Detection of Cattle Infected with Mycobacterium bovis: Comparisons to IFN-γ Responses

2012 ◽  
Vol 19 (3) ◽  
pp. 346-351 ◽  
Author(s):  
W. R. Waters ◽  
T. C. Thacker ◽  
B. J. Nonnecke ◽  
M. V. Palmer ◽  
I. Schiller ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Similar Pattern ◽  
Gamma Interferon ◽  
Content Type ◽  
Purified Protein Derivative ◽  
Testing Protocol ◽  
Archived Samples ◽  
Ifn Γ ◽  
Highly Correlated ◽  
Mycobacterial Antigens

ABSTRACTGamma interferon (IFN-γ)-induced protein 10 (IP-10) has recently shown promise as a diagnostic biomarker ofMycobacterium tuberculosisinfection of humans. The aim of the current study was to compare IP-10 and IFN-γ responses uponMycobacterium bovisinfection in cattle by using archived samples from two aerosol inoculation studies. In the first study (104CFUM. bovisby aerosol,n= 7),M. bovispurified protein derivative (PPDb)-specific IP-10 and IFN-γ gene expression was detected as early as 29 days after challenge. PPDb-specific IP-10 and IFN-γ mRNA responses followed a similar pattern of expression over the course of this study and were highly correlated (r= 0.87). In the second study (105CFUM. bovisby aerosol,n= 5), IP-10 and IFN-γ (protein) responses to mycobacterial antigens were compared following challenge. IFN-γ responses to mycobacterial antigens were detected at 29 days after challenge and were sustained during the remainder of the study. IFN-γ responses to mycobacterial antigens exceeded corresponding responses in nonstimulated cultures. IP-10 responses to mycobacterial antigens exceeded preinfection responses at 7, 29, and 63 days after challenge. In contrast to IFN-γ responses, IP-10 responses to mycobacterial antigens generally did not exceed the respective responses in nonstimulated cultures. IP-10 responses to medium alone and to mycobacterial antigens followed a similar pattern of response. Correlations between IP-10 and IFN-γ (protein) responses were modest (r≈ 0.50 to 0.65). Taken together, these findings do not support the use of IP-10 protein as a biomarker for bovine tuberculosis using the current testing protocol and reagents; however, mRNA-based assays may be considered for further analysis.

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