Human leucocyte antigen-A2 restricted and Mycobacterium tuberculosis 19-kDa antigen-specific CD8+ T-cell responses are oligoclonal and exhibit a T-cell cytotoxic type 2 response cytokine-secretion pattern.
CD8+ T cells can be grouped into two different types of secretory T lymphocytes, based on the cytokine-secretion pattern upon antigen exposure: those with a T-cell cytotoxic type 1 response (Tc1), which secrete interferon-gamma (IFN-gamma), or those with a T-cell cytotoxic type 2 response, which secrete interleukin (IL)-4 and IL-10. We examined the CD8+ T-cell response directed against an immunodominant human leucocyte antigen (HLA)-A2-presented peptide derived from a 19-kDa Mycobacterium tuberculosis-associated antigen. T cells were examined by functional analysis and by T-cell receptor (TCR) complementarity-determining region 3 (CDR3)-spectratyping, which defines the complexity of a T-cell response. T-cell stimulation with the immunodominant VLTDGNPPEV epitope yielded a Tc2 (IL-4) cytokine-secretion pattern and resulted in oligoclonal expansion of TCR-variable beta chain (VB) families, which differed from patient to patient. Generation of T-cell clones corroborated the notion that the CD8+ T-cell response directed against the HLA-A2-presented VLTDGNPPEV epitope leads to a Tc2 cytokine-secretion pattern in CD8+ T cells, as defined by IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. Characterization of the cytokine-secretion profile in HLA-A2/VLTDGNPPEV-tetramer sorted T cells from patients with active tuberculosis supported this observation: peptide-specific T cells from three of three patients secreted IL-4 and only one of three patients produced IFN-gamma in response to the nominal target epitope. Permutation of this T-cell epitope may aid to elicit a qualitatively different CD8+ T-cell response in patients with M. tuberculosis infection.
Höhn
H
H
Institute for Medical Microbiology, University of Mainz, Hochhaus Augustusplatz, Mainz, Germany.
Kortsik
C
C
Nilges
K
K
Necker
A
A
Freitag
K
K
Tully
G
G
Neukirch
C
C
Maeurer
M J
MJ
D000942:Antigens, Bacterial / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells / Q000276:immunology; D022801:Complementarity Determining Regions / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000276:immunology*
D000942:Antigens, Bacterial; D022801:Complementarity Determining Regions; D015789:HLA-A2 Antigen; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor