Identification of major epitopes of Mycobacterium tuberculosis AG85B that are recognized by HLA-A*0201-restricted CD8+ T cells in HLA-transgenic mice and humans.
CD8(+) T cells are thought to play an important role in protective immunity to tuberculosis. Although several nonprotein ligands have been identified for CD1-restricted CD8(+) CTLs, epitopes for classical MHC class I-restricted CD8(+) T cells, which most likely represent a majority among CD8(+) T cells, have remained ill defined. HLA-A*0201 is one of the most prevalent class I alleles, with a frequency of over 30% in most populations. HLA-A2/K(b) transgenic mice were shown to provide a powerful model for studying induction of HLA-A*0201-restricted immune responses in vivo. The Ag85 complex, a major component of secreted Mycobacterium tuberculosis proteins, induces strong CD4(+) T cell responses in M. tuberculosis-infected individuals, and protection against tuberculosis in Ag85-DNA-immunized animals. In this study, we demonstrate the presence of HLA class I-restricted, CD8(+) T cells against Ag85B of M. tuberculosis in HLA-A2/K(b) transgenic mice and HLA-A*0201(+) humans. Moreover, two immunodominant Ag85 peptide epitopes for HLA-A*0201-restricted, M. tuberculosis-reactive CD8(+) CTLs were identified. These CD8(+) T cells produced IFN-gamma and TNF-alpha and recognized Ag-pulsed or bacillus Calmette-Guérin-infected, HLA-A*0201-positive, but not HLA-A*0201-negative or uninfected human macrophages. This CTL-mediated killing was blocked by anti-CD8 or anti-HLA class I mAb. Using fluorescent peptide/HLA-A*0201 tetramers, Ag85-specific CD8(+) T cells could be visualized in bacillus Calmette-Guérin-responsive, HLA-A*0201(+) individuals. Collectively, our results demonstrate the presence of HLA class I-restricted CD8(+) CTL against a major Ag of M. tuberculosis and identify Ag85B epitopes that are strongly recognized by HLA-A*0201-restricted CD8(+) T cells in humans and mice. These epitopes thus represent potential subunit components for the design of vaccines against tuberculosis.
Geluk
A
A
Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands. ageluk@lumc.nl
van Meijgaarden
K E
KE
Franken
K L
KL
Drijfhout
J W
JW
D'Souza
S
S
Necker
A
A
Huygen
K
K
Ottenhoff
T H
TH
D000217:Acyltransferases; D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D004269:DNA, Bacterial / Q000008:administration & dosage / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D006183:H-2 Antigens / Q000235:genetics / Q000378:metabolism*; D015789:HLA-A2 Antigen / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D016056:Immunodominant Epitopes / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007273:Injections, Intramuscular; D051379:Mice; D008822:Mice, Transgenic; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010449:Peptide Mapping; D010957:Plasmids / Q000008:administration & dosage / Q000138:chemical synthesis / Q000276:immunology; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D018984:Epitopes, T-Lymphocyte; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D015789:HLA-A2 Antigen; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D000217:Acyltransferases; C112580:antigen 85A, Mycobacterium tuberculosis