Reference
Reference TypeLiterature
TitleMapping of T cell epitopes of the 30-kDa alpha antigen of Mycobacterium bovis strain bacillus Calmette-Guérin in purified protein derivative (PPD)-positive individuals.
AuthorsR F Silver; R S Wallis; J J Ellner
AffiliationsDivision of Infectious Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
JournalJ Immunol
Year1995
AbstractThe fibronectin-binding 30-kDa alpha Ag is a major secretory protein of growing mycobacteria that stimulates in vitro lymphocyte blastogenesis in most healthy purified protein derivative-positive individuals, but only a minority of patients with active tuberculosis. T cell epitopes of the alpha Ag were assessed using blastogenic responses of PBMC from 12 healthy purified protein derivative-positive subjects to a set of synthetic peptides based on the 325-amino acid sequence of the alpha Ag of Mycobacterium bovis BCG. Because epitope-specific precursor cells are infrequent and randomly distributed, we used Poisson analysis to determine positive responses to 10 micrograms/ml of each peptide in 12 replicate culture wells. Seven immunodominant regions of the alpha Ag were identified. Each subjects responded to at least one of the two most dominant epitopes, which correspond to amino acids 131-155 and 233-257 (from N terminus). Peptides of these two epitopes induced production of IFN-gamma by sorted CD4+ T cells. The immunodominant peptides may have use a components of a vaccine and as tools to study the evolution of the immune response to M. tuberculosis. The two most dominant epitopes both occur in regions of the alpha Ag that differ from those of the atypical pathogens M. avium and M. kansasii. In addition, the M. bovis epitope of amino acids 133-155 differs from that of M. tuberculosis by a single amino acid. It may be possible to exploit the sequence differences for development of diagnostic tests with increased specificity.
Curation Last Updated2023-08-18 20:06:58
Epitope
Epitope ID49871
Chemical TypeLinear peptide
Linear SequencePVGGQSSFYSDWYSP
Source Molecule Namesecreted antigen 85-B fbpB
Source OrganismMycobacterium tuberculosis variant bovis BCG
Starting Position111
Ending Position125
Epitope Reference Details
Epitope Structure DefinesEpitope containing region/antigenic site
Epitope Namepeptide 23
Reference Starting Position111
Reference Ending Position125
Location of Data in ReferenceFigure 3
Immunization
Host OrganismHomo sapiens (human)
1st In Vivo Process
In Vivo Process TypeExposure with existing immune reactivity without evidence for disease
Disease Statehealthy
1st Immunogen
Epitope RelationTaxonomic Sibling
Object TypeOrganism
OrganismMycobacterium tuberculosis
Immunogen Details
Immunogen Reference NameMycobacterium tuberculosis
Immunization Comments
Immunization CommentsSubjects were healthy PPD+ with a history of occupational or endemic exposure to M. tuberculosis.
T Cell Assay
Qualitative MeasurementPositive
Method/Technique3H-thymidine
Measurement ofproliferation
Measurement Details
Number of Subjects Tested5
Number of Subjects Responded1
Response Frequency (%)20
Effector Cells
Effector Cell Tissue TypeBlood
Effector Cell TypePBMC
Effector Cell Culture ConditionsDirect Ex Vivo
MHC Allele
MHC Allele NameHLA class II
MHC Evidence CodeT cell assay -Biological process measured
Antigen
Epitope RelationEpitope
Chemical TypeLinear peptide
Linear SequencePVGGQSSFYSDWYSP
Source Molecule Namesecreted antigen 85-B fbpB
Source OrganismMycobacterium tuberculosis variant bovis BCG
Starting Position111
Ending Position125
Antigen Details
Antigen Reference Namepeptide 23
Assay Reference Details
Location of Assay Data in ReferenceFigure 2