title: Mapping of V beta 11+ helper T cell epitopes on mycobacterial antigen in mouse primed with Mycobacterium tuberculosis.
abstract: Antigenic epitopes for Mycobacterium tuberculosis-reactive T cell immune responses have been mapped using the purified Mycobacterium protein antigen. Lymph node cells from C57BL/6 mice that had been immunized with heat-killed M. tuberculosis were cultured with various Mycobacterium protein antigens and their reactivity was monitored by proliferative response. Usage of the TCR beta chain repertoire was analyzed by flow cytometry. Stimulation of M. tuberculosis-primed lymph node cells with MPT59 (antigen 85B, alpha antigen) induced proliferative response, production of IL-2 and IFN-gamma, and the expansion of V beta 11+ CD4+ T cells in conjunction with antigen-presenting cells in an I-Ab-restricted manner. Lymph node cells from non-primed mice failed to proliferate in response to MPT59. Using peptides covering the complete mature 285 amino acids long MPT59 protein as 15-mer molecules overlapping by five amino acids, we identified the antigenic epitope for MPT59-specific V beta 11+ T cells. The 15-mer peptide, covering amino acid residues 240-254 of MPT59 [peptide-25 (amino acids 240-254)], contains the motif that is conserved for I-Ab and requires processing by antigen-presenting cells to trigger peptide-25-specific V beta 11+ CD4+ T cells. We conclude from these results that MPT59 and peptide-25 (amino acids 240-254) are not superantigens and require antigen processing in order to stimulate V beta 11+ Th1 cells. This experimental system will provide us with a useful tool for delineating the regulation of T cell development in a particular subset of M. tuberculosis infection and for developing antigenic peptides for Th1-dominant immune responses.
authors.affiliation: Department of Immunology, Institute of Medical Science, University of Tokyo, Minato-ku, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yanagisawa
authors.forename: M
authors.initials: M
authors.lastname: Koike
authors.forename: A
authors.initials: A
authors.lastname: Kariyone
authors.forename: S
authors.initials: S
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Takatsu
mesh_terms: D000217:Acyltransferases; D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000276:immunology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015704:CD4 Antigens; D018984:Epitopes, T-Lymphocyte; D007376:Interleukin-2; D016693:Receptors, Antigen, T-Cell, alpha-beta; C052242:alpha antigens, Mycobacterium; D007371:Interferon-gamma; D000217:Acyltransferases; C121433:antigen 85B, Mycobacterium tuberculosis