Reference
Reference TypeLiterature
TitleAntigen mining with iterative genome screens identifies novel diagnostics for the Mycobacterium tuberculosis complex.
AuthorsKatie Ewer; Paul Cockle; Steve Gordon; Huma Mansoor; Marc Govaerts; Karl Walravens; Sylvie Marché; Glyn Hewinson; Martin Vordermeier
AffiliationsTB Research Group, Veterinary Laboratories Agency-Weybridge, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom. k.ewer@vla.defra.gsi.gov.uk.
JournalClin Vaccine Immunol
Year2006
AbstractThe definition of antigens for the diagnosis of human and bovine tuberculosis is a research priority. If diagnosis is to be used alongside Mycobacterium bovis BCG-based vaccination regimens, it will be necessary to have reagents that allow the discrimination of infected and vaccinated animals. A list of 42 potential M. bovis-specific antigens was prepared by comparative analysis of the genomes of M. bovis, M. avium subsp. avium, M. avium subsp. paratuberculosis, and Streptomyces coelicolor. Potential antigens were tested by applying them in a high-throughput peptide-based screening system to M. bovis-infected and BCG-vaccinated cattle and to cattle without prior exposure to M. bovis. A response hierarchy of antigens was established by comparing responses in infected animals. Three antigens (Mb2555, Mb2890, and Mb3895) were selected for further study, as they were strongly recognized in experimentally infected animals but with low or no frequency in BCG-vaccinated and naïve cows. Interestingly, all three antigens were recognized in animals vaccinated against Johne's disease, suggesting the presences of epitopes cross-reacting with M. avium subsp. paratuberculosis antigens. Eight peptides from the three antigens studied in detail were identified as immunodominant and were characterized in terms of major histocompatibility complex class II restriction element usage and shown to be restricted through both DR and DQ molecules. Reasons for antigenic cross-reactivity with M. avium subsp. paratuberculosis and refinement of the in silico strategy to predict such cross-reactivity from the primary protein sequence will be discussed. Evaluation of the peptides identified from the three dominant antigens by use of larger field studies is now a priority.
Curation Last Updated2023-08-18 20:09:54
Epitope
Epitope ID11989
Chemical TypeLinear peptide
Linear SequenceEFETTRSSTGTGLQGVTSGL
Source Molecule Namehypothetical protein Mb3895
Source OrganismMycobacterium tuberculosis variant bovis AF2122/97
Starting Position57
Ending Position76
Epitope Reference Details
Epitope Structure DefinesEpitope containing region/antigenic site
Epitope NameMb3895 p57-76
Reference Starting Position57
Reference Ending Position76
CommentsThis peptide epitope was selected from a panel of 20mer overlapping peptides representing the entire length of the conserved hypothetical protein identified by an iterative genome screen of Mycobacterium bovis using StandAlone TBLASTIN (NCBI).
Location of Data in ReferenceAuthor provided
Immunization
Host OrganismBos taurus (bovine)
1st In Vivo Process
In Vivo Process TypeAdministration in vivo
Disease Statetuberculosis
Disease StageAcute/Recent onset;OGMS:0000094
Administration Details
Routeintratracheal
1st Immunogen
Epitope RelationSource Organism
Object TypeOrganism
OrganismMycobacterium tuberculosis variant bovis AF2122/97
Immunogen Details
Immunogen Reference NameMycobacterium bovis AF2122/97
Immunization Comments
Immunization CommentsEleven calves were previously exposed by natural infection with M. bovis in the field. Twenty-one calves from BTB-free herds were also immunized by experimental infection with 1-1000 CFUs of M. bovis (AF2122/97). Active bovine TB was confirmed by skin test, bacterial culture and postmortem pathology. Blood was collected 18 weeks post-infection.
T Cell Assay
Qualitative MeasurementPositive
Method/TechniqueELISA
Measurement ofIFNg release
Effector Cells
Effector Cell Tissue TypeBlood
Effector Cell TypePBMC
Effector Cell Culture ConditionsDirect Ex Vivo
Antigen Presenting Cells
Cell Tissue TypeBlood
Cell TypePBMC
Cell Culture ConditionsDirect Ex Vivo
Antigen
Epitope RelationEpitope
Chemical TypeLinear peptide
Linear SequenceEFETTRSSTGTGLQGVTSGL
Source Molecule Namehypothetical protein Mb3895
Source OrganismMycobacterium tuberculosis variant bovis AF2122/97
Starting Position57
Ending Position76
Antigen Details
Antigen Reference NameMb3895 p57-76
Assay Reference Details
Assay Comments by IEDB CuratorThe ability of individual Mb3895 peptides to induce IFNg production from the PBMCs of cattle infected with M. bovis was evaluated using ELISA. By comparison to the other peptides, this peptide was capable of inducing only low levels of IFNg.
Location of Assay Data in ReferenceFigure 2