Assessment of cross-reactivity between Mycobacterium bovis and M. kansasii ESAT-6 and CFP-10 at the T-cell epitope level.
Cross-reactivity between Mycobacterium kansasii ESAT-6 and CFP-10 homologues and their M. bovis counterparts can confound the interpretation of immunodiagnostic tests for tuberculosis. M. kansasii is a nontuberculous mycobacterial species cultured from skin test-positive cattle in Great Britain. Using peptides derived from M. bovis and M. kansasii ESAT-6 and CFP-10 regions that differ between these species, we investigated the species specificity and cross-reactivity at the level of individual bovine T-cell epitopes. Our results demonstrated that all peptides tested are fully cross-reactive, with the exception of one ESAT-6-derived peptide that harbored an M. bovis-specific epitope(s) when it was recognized in the context of bovine leukocyte antigen (BoLA)-DQ but that was cross-reactive with its M. kansasii homologues when it was restricted by BoLA-DR. This observation further highlights that prediction of species specificity by comparing sequence identity/homology alone is not sufficient and that individuals with diverse major histocompatibility complex constellations need to be tested to characterize the cross-reactivity or species specificity of peptide-based reagents.
Vordermeier
H Martin
HM
TB Research Group, Department of Statutory and Exotic Bacterial Diseases, Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone KT15 3NB, United Kingdom. m.vordermeier@vla.defra.gsi.gov.uk
Brown
Jemma
J
Cockle
Paul J
PJ
Franken
Willeke P J
WP
Drijfhout
Jan Wouter
JW
Arend
Sandra M
SM
Ottenhoff
Tom H M
TH
Jahans
Keith
K
Hewinson
R Glyn
RG
D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D001717:Birds; D002417:Cattle; D003429:Cross Reactions / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D008969:Molecular Sequence Data; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000276:immunology; D009163:Mycobacterium bovis / Q000276:immunology* / Q000302:isolation & purification; D019909:Mycobacterium kansasii / Q000276:immunology* / Q000302:isolation & purification; D013045:Species Specificity
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D018984:Epitopes, T-Lymphocyte