High frequency of CD4+ T cells specific for the TB10.4 protein correlates with protection against Mycobacterium tuberculosis infection.
TB10.4 is a newly identified antigen of Mycobacterium tuberculosis recognized by human and murine T cells upon mycobacterial infection. Here, we show that immunization with Mycobacterium bovis BCG induces a strong, genetically controlled, Th1 immune response against TB10.4 in mice. BALB/c and C57BL/6 strains behave as high and low responders to TB10.4 protein, respectively. The TB10.4:74-88 peptide was identified as an immunodominant CD4+ T-cell epitope for H-2d mice. Since recent results, as well as the present study, have raised interest in TB10.4 as a subunit vaccine, we analyzed immune responses induced by this antigen delivered by a new vector, the adenylate cyclase (CyaA) of Bordetella pertussis. CyaA is able to target dendritic cells and to deliver CD4+ or CD8+ T-cell epitopes to the major histocompatibility complex class II/I molecule presentation pathways, triggering specific Th1 or cytotoxic T-lymphocyte (CTL) responses. Several CyaA harboring either the entire TB10.4 protein or various subfragments containing the TB10.4:20-28 CTL epitope were shown to induce TB10.4-specific Th1 CD4+ and CD8+ T-cell responses. However, none of the recombinant CyaA, injected in the absence of adjuvant, was able to induce protection against M. tuberculosis infection. In contrast, TB10.4 protein administered with a cocktail of strong adjuvants that triggered a strong Th1 CD4+ T-cell response induced significant protection against M. tuberculosis challenge. These results confirm the potential value of the TB10.4 protein as a candidate vaccine and show that the presence of high frequencies of CD4+ T cells specific to this strong immunogen correlates with protection against M. tuberculosis infection.
Hervas-Stubbs
Sandra
S
Biologie des Régulations Immunitaires, Inserm, E 352, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France.
Majlessi
Laleh
L
Simsova
Marcela
M
Morova
Jana
J
Rojas
Marie-Jesus
MJ
Nouzé
Clémence
C
Brodin
Priscille
P
Sebo
Peter
P
Leclerc
Claude
C
D000262:Adenylyl Cyclases / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016764:Cell Polarity; D018984:Epitopes, T-Lymphocyte; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D014376:Tuberculosis / Q000276:immunology*; D032581:Tuberculosis Vaccines / Q000276:immunology*; D022223:Vaccines, Subunit / Q000276:immunology
D000942:Antigens, Bacterial; D001500:BCG Vaccine; D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; C501710:TB10.4 antigen, Mycobacterium tuberculosis; D032581:Tuberculosis Vaccines; D022223:Vaccines, Subunit; D000262:Adenylyl Cyclases