title: Induction of in vivo functional Db-restricted cytolytic T cell activity against a putative phosphate transport receptor of Mycobacterium tuberculosis.
abstract: Using plasmid vaccination with DNA encoding the putative phosphate transport receptor PstS-3 from Mycobacterium tuberculosis and 36 overlapping 20-mer peptides spanning the entire PstS-3 sequence, we determined the immunodominant Th1-type CD4(+) T cell epitopes in C57BL/10 mice, as measured by spleen cell IL-2 and IFN-gamma production. Furthermore, a potent IFN-gamma-inducing, D(b)-restricted CD8(+) epitope was identified using MHC class I mutant B6.C-H-2(bm13) mice and intracellular IFN-gamma and whole blood CD8(+) T cell tetramer staining. Using adoptive transfer of CFSE-labeled, peptide-pulsed syngeneic spleen cells from naive animals into DNA vaccinated or M. tuberculosis-infected recipients, we demonstrated a functional in vivo CTL activity against this D(b)-restricted PstS-3 epitope. IFN-gamma ELISPOT responses to this epitope were also detected in tuberculosis-infected mice. The CD4(+) and CD8(+) T cell epitopes defined for PstS-3 were completely specific and not recognized in mice vaccinated with either PstS-1 or PstS-2 DNA. The H-2 haplotype exerted a strong influence on immune reactivity to the PstS-3 Ag, and mice of the H-2(b, p, and f) haplotype produced significant Ab and Th1-type cytokine levels, whereas mice of H-2(d, k, r, s, and q) haplotype were completely unreactive. Low responsiveness against PstS-3 in MHC class II mutant B6.C-H-2(bm12) mice could be overcome by DNA vaccination. IFN-gamma-producing CD8(+) T cells could also be detected against the D(b)-restricted epitope in H-2(p) haplotype mice. These results highlight the potential of DNA vaccination for the induction and characterization of CD4(+) and particularly CD8(+) T cell responses against mycobacterial Ags.
authors.affiliation: Laboratory of Mycobacterial Immunology, Pasteur Institute of Brussels, Brussels, Belgium.
authors.forename: Marta
authors.initials: M
authors.lastname: Romano
authors.forename: Olivier
authors.initials: O
authors.lastname: Denis
authors.forename: Sushila
authors.initials: S
authors.lastname: D'Souza
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Wang
authors.forename: Tom H M
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Brulet
authors.forename: Kris
authors.initials: K
authors.lastname: Huygen
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte; D006183:H-2 Antigens / Q000502:physiology*; D064532:Histocompatibility Antigen H-2D; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D032581:Tuberculosis Vaccines / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology
chemical_list: D018528:ATP-Binding Cassette Transporters; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D018984:Epitopes, T-Lymphocyte; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D007376:Interleukin-2; C102010:PstS-3 protein, Mycobacterium tuberculosis; D032581:Tuberculosis Vaccines; D019444:Vaccines, DNA; D007371:Interferon-gamma