Open AccessAntigenic Equivalence of Human T-Cell Responses to Mycobacterium tuberculosis -Specific RD1-Encoded Protein Antigens ESAT-6 and Culture Filtrate Protein 10 and to Mixtures of Synthetic Peptides
Author(s) -
Sandra M. Arend,
Annemieke Geluk,
Krista E. van Meijgaarden,
Jaap T. van Dissel,
Michael Theisen,
Peter Andersen,
Tom H. M. Ottenhoff
Publication year - 2000
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.68.6.3314-3321.2000
Subject(s) - esat 6 , antigen , biology , mycobacterium bovis , recombinant dna , mycobacterium tuberculosis , virology , microbiology and biotechnology , mycobacterium , tuberculosis vaccines , tuberculosis , immunology , biochemistry , bacteria , gene , genetics , medicine , pathology
The early secreted antigenic target 6-kDa protein (ESAT-6) and culture filtrate protein 10 (CFP-10) are promising antigens for reliable immunodiagnosis of tuberculosis. Both antigens are encoded by RD1, a genomic region present in all strains ofMycobacterium tuberculosis andM. bovis but lacking in allM. bovis bacillus Calmette-Guérin vaccine strains. Production and purification of recombinant antigens are laborious and costly, precluding rapid and large-scale testing. Aiming to develop alternative diagnostic reagents, we have investigated whether recombinant ESAT-6 (rESAT-6) and recombinant CFP-10 (rCFP-10) can be replaced with corresponding mixtures of overlapping peptides spanning the complete amino acid sequence of each antigen. Proliferation ofM. tuberculosis -specific human T-cell lines in response to rESAT-6 and rCFP-10 and that in response to the corresponding peptide mixtures were almost completely correlated (r = 0.96,P < 0.0001 for ESAT-6;r = 0.98,P < 0.0001 for CFP-10). More importantly, the same was found when gamma interferon production by peripheral blood mononuclear cells in response to these stimuli was analyzed (r = 0.89,P < 0.0001 for ESAT-6;r = 0.89,P < 0.0001 for CFP-10). Whole protein antigens and the peptide mixtures resulted in identical sensitivity and specificity for detection of infection withM. tuberculosis . The peptides in each mixture contributing to the overall response varied between individuals with different HLA-DR types. Interestingly, responses to CFP-10 were significantly higher in the presence of HLA-DR15, which is the major subtype of DR2. These results show that mixtures of synthetic overlapping peptides have potency equivalent to that of whole ESAT-6 and CFP-10 for sensitive and specific detection of infection withM. tuberculosis , and peptides have the advantage of faster production at lower cost.