Induction of In Vivo Functional Db-Restricted Cytolytic T Cell Activity against a Putative Phosphate Transport Receptor of Mycobacterium tuberculosis

• Published in: The Journal of immunology (1950) Vol. 172; no. 11; pp. 6913 - 6921
• Main Authors: Romano, Marta, Denis, Olivier, D'Souza, Sushila, Wang, Xiao-Ming, Ottenhoff, Tom H. M, Brulet, Jean-Marc, Huygen, Kris
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.06.2004
• Subjects: Amino Acid Sequence; Animals; Antibodies, Bacterial - blood; ATP-Binding Cassette Transporters - immunology; Bacterial Proteins - immunology; Epitopes, T-Lymphocyte; H-2 Antigens - physiology; Histocompatibility Antigen H-2D; Interferon-gamma - biosynthesis; Interleukin-2 - biosynthesis; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Mycobacterium tuberculosis - immunology; T-Lymphocytes, Cytotoxic - immunology; Th1 Cells - immunology; Tuberculosis Vaccines - immunology; Vaccines, DNA - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.172.11.6913

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.