Reference
Reference TypeLiterature
IEDB_Reference:921
TitleEpitope focus, clonal composition and Th1 phenotype of the human CD4 response to the secretory mycobacterial antigen Ag85.
AuthorsM T Valle; A M Megiovanni; A Merlo; G Li Pira; L Bottone; G Angelini; L Bracci; L Lozzi; K Huygen; F Manca
AffiliationsImmunology Laboratory, San Martino Hospital and Unit of Retroviral Immunology, Advanced Biotechnology Centre, Genoa, Italy.
JournalClin Exp Immunol
PMID:11207652
Year2001
AbstractLymphoproliferation of healthy donors was tested against mycobacterial antigens (PPD, Ag85, Ag85 peptides). All PPD responders recognized the secretory antigen Ag85 and the peptide specificity for Ag85B was defined. Peptide 91-108 was recognized by 85% of donors. In addition, all CD4 T cell lines generated from 12 donors against PPD or Ag85 responded to 91-108. When this peptide was used to generate T cell lines, the cells responded also to tuberculins from atypical mycobacterial species. Thus the cross-reactive peptide behaved as quasi-universal. The analysis of TCR-BV gene usage by cell lines showed that most Ag85-specific T cells correspond to 91-108-specific clonotypes. Intracytoplasmic staining of cell lines after phorbol myristate acetate stimulation resulted in dominance of interferon-gamma (IFN-gamma)-IL-4 double-positive cells, whereas antigen stimulation resulted in production of IFN-gamma only. The data show that peptide 91-108 is the major focus of the CD4 response to mycobacterial antigens in peripheral blood mononuclear cells and in T cell lines from PPD responders.
Curation Last Updated2023-08-18 20:02:22
Epitope
Epitope ID36536
IEDB_epitope:36536
Chemical TypeLinear peptide
Linear SequenceLIGLAMGDAGGYKAADMW
Source Molecule Namealpha-antigen
GenPept:AAA25359.1
Source OrganismMycobacterium tuberculosis variant bovis BCG
NCBITaxon:33892
Starting Position201
Ending Position218
Epitope Reference Details
Epitope Structure DefinesEpitope containing region/antigenic site
Epitope NamePeptide 19
Reference Starting Position163
Reference Ending Position180
CommentsSource protein and 85A and 85C proteins conform the Ag85 complex. Genbank entry includes the 40aa signal peptide not included in this study, so that different positions are indicated for the epitope.
Location of Data in ReferenceAuthor's communication
Immunization
Host OrganismHomo sapiens (human)
NCBITaxon:9606
1st In Vivo Process
In Vivo Process TypeExposure with existing immune reactivity without evidence for disease
OBI:1110061
Disease Statehealthy
ONTIE:0003423
Immunization Comments
Immunization CommentsThe donors are PPD+ but otherwise healthy. No information on the origin of the reactivity is provided.
T Cell Assay
Qualitative MeasurementPositive
Method/Technique3H-thymidine
OBI:1110180
Measurement ofproliferation
Measurement Details
Number of Subjects Tested14
Number of Subjects Responded4
Response Frequency (%)28.6
Effector Cells
Effector Cell Tissue TypeBlood
UBERON:0000178
Effector Cell TypePBMC
CL:2000001
Effector Cell Culture ConditionsDirect Ex Vivo
Antigen Presenting Cells
Cell Tissue TypeBlood
UBERON:0000178
Cell TypePBMC
CL:2000001
Cell Culture ConditionsDirect Ex Vivo
MHC Allele
MHC Allele NameHLA class II
MRO:0001455
MHC Evidence CodeT cell assay -Biological process measured
ECO:0008083
Antigen
Epitope RelationEpitope
Chemical TypeLinear peptide
Linear SequenceLIGLAMGDAGGYKAADMW
Source Molecule Namealpha-antigen
GenPept:AAA25359.1
Source OrganismMycobacterium tuberculosis variant bovis BCG
NCBITaxon:33892
Starting Position201
Ending Position218
Antigen Details
Antigen Reference NamePeptide 19
Assay Reference Details
Assay Comments by IEDB Curator28.6% of healthy Purified Protein Derivative positive ( PPD+) individuals studied recognize this peptide with a SI>2. None of the CD4+ T cell lines derived from PMBCs by stimulation with Ag85 or with PPD recognize the peptide.
Location of Assay Data in ReferenceFigures 1 and 2