Project description:New tuberculosis vaccines are highly desirable and urgently needed since the attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) provides only variable efficacy against the pulmonary form of the disease. The region of difference 1 (RD1), which is deleted in BCG and strongly impacts on Mycobacterium tuberculosis (Mtb) virulence and immunogenicity, represents a crucial locus to be engineered for either the improvement of the current BCG vaccine, or the attenuation of Mtb. Therefore, mutants secreting or not wild-type or mutated variants of the RD1-encoded 6 kDa early secreted antigenic target (ESAT-6) were generated. Comparative analysis of the transcriptome, phenotype, cytokine production profiles and the capacity to promote T cell responses were conducted in human primary dendritic cells (DCs), as they represent critical regulators of vaccine-induced immunity, unveiling a distinct immunogenic potential for BCG or Mtb mutants. In contrast to Mtb, BCG induced a poor DC maturation, and to our surprise, a BCG strain complemented with the RD1 region only partially restored DC maturation and expansion of interferon (IFN)-γ producing T cells. In contrast, infection with a recombinant attenuated Mtb strain, secreting a truncated version of ESAT-6 lacking 11 amino acids at the C-terminus portion, drove full maturation in infected DC and maintained their capacity to promote polarization of T helper (Th) 1 cells, as observed upon infection with the virulent Mtb. We performed a comparative microarray analysis of dendritic cells (DCs), infected with Mtb and BCG strains, expressing/complemented (MtbÎRD1::RD1 and BCG::RD1) or not (MtbÎRD1::B412 and BCG::B412) the/with the RD1 region. DCs were challenged with different BCG and Mtb recombinant strains for 8h.
Project description:New tuberculosis vaccines are highly desirable and urgently needed since the attenuated Mycobacterium bovis Bacillus Calmette-Guerin (BCG) provides only variable efficacy against the pulmonary form of the disease. The region of difference 1 (RD1), which is deleted in BCG and strongly impacts on Mycobacterium tuberculosis (Mtb) virulence and immunogenicity, represents a crucial locus to be engineered for either the improvement of the current BCG vaccine, or the attenuation of Mtb. Therefore, mutants secreting or not wild-type or mutated variants of the RD1-encoded 6 kDa early secreted antigenic target (ESAT-6) were generated. Comparative analysis of the transcriptome, phenotype, cytokine production profiles and the capacity to promote T cell responses were conducted in human primary dendritic cells (DCs), as they represent critical regulators of vaccine-induced immunity, unveiling a distinct immunogenic potential for BCG or Mtb mutants. In contrast to Mtb, BCG induced a poor DC maturation, and to our surprise, a BCG strain complemented with the RD1 region only partially restored DC maturation and expansion of interferon (IFN)-γ producing T cells. In contrast, infection with a recombinant attenuated Mtb strain, secreting a truncated version of ESAT-6 lacking 11 amino acids at the C-terminus portion, drove full maturation in infected DC and maintained their capacity to promote polarization of T helper (Th) 1 cells, as observed upon infection with the virulent Mtb.
Project description:This project involves RNA-Seq analysis of samples obtained from the Phase IIA clinical trial TB-019 (NCT01669096) which evaluated kinetics of response, safety, and immunogenicity of the GSK Mycobacterium tuberculosis (MTB) vaccine M72/AS01E (“GSK M72”). GSK M72 consists of the M72 recombinant fusion of Mycobacterium tuberculosis (MTB) proteins Rv0125 and Rv1196 in combination with the liposome, TLR4 ligand (MPL), and QS21 saponin adjuvant AS01E (Leroux-Roels et al., 2013).
Project description:Transcriptional profiling of Mycobacterium tuberculosis H37Rv exposed to immune sera from C57/BL6 mice immunized with a conjugate of Bacillus anthracis protective antigen and arabinomannan vs. protective antigen alone
Project description:In Balb/c mice, the presence of effector CD8 T cells in lungs after intra-nasal (IN) immunization with replication deficient recombinant Adenovirus expressing the 85A antigen from Mycobacterium tuberculosis (MTb) (Ad85A) correlates with protection against aerosol MTb infection. In order to identify differentially expressed transcripts which contribute to protection by IN immunized lung CD8 T cells, total RNA from CD8 T cells isolated from target tissue (lungs) and lymphoid organ (spleen ) after a protective (IN) and non-protective (intradermal, ID) immunization regime will be analyzed in a whole-genome microarray study.
Project description:Liquid chromatography coupled mass spectrometry (LC-MS) operating in targeted mass spectrometry (MS) including multiple reaction monitoring (MRM) mode is an accurate analytical method. Integrating with nanoelectrospray-tandem MS (NanoES-MS/MS) and immunoprecipitation (IP), it becomes a promising method in detecting pathogen derived antigens which are at extremely low concentrations, such as mycobacterium tuberculosis (Mtb) secreted 10 kDa culture filtrate antigen (CFP-10). We employed an optimum denaturing condition for trypsin digestion and imunoprecipitation of targeted peptides and applied this method in clinical samples.
Project description:T cells are required for protective immunity against Mycobacterium tuberculosis. We recently described a cohort of Ugandan household contacts of tuberculosis cases who appear to “resist” M. tuberculosis infection (resisters; RSTRs) and showed that these individuals harbor IFN-γ–independent T cell responses to M. tuberculosis–specific peptide antigens. However, T cells also recognize nonprotein antigens via antigen-presenting systems that are independent of genetic background, known as donor-unrestricted T cells (DURTs). We used tetramer staining and flow cytometry to characterize the association between DURTs and “resistance” to M. tuberculosis infection. Peripheral frequencies of most DURT subsets were comparable between RSTRs and latently infected controls (LTBIs). However, we observed a 1.65-fold increase in frequency of MR1-restricted T (MR1T) cells among RSTRs in comparison with LTBIs. Single-cell RNA sequencing of 18,251 MR1T cells sorted from 8 donors revealed 5,150 clonotypes that expressed a common transcriptional program, the majority of which were private. Sequencing of the T cell receptor α/T cell receptor δ (TCRα/δ) repertoire revealed several DURT clonotypes were expanded among RSTRs, including 2 MR1T clonotypes that recognized mycobacteria-infected cells in a TCR-dependent manner. Overall, our data reveal unexpected donor-specific diversity in the TCR repertoire of human MR1T cells as well as associations between mycobacteria-reactive MR1T clonotypes and resistance to M. tuberculosis infection.
Project description:In this study, we report the identification and characterization of several regulators in Mycobacterium tuberculosis. WT and mutant Mtb cells were grown in Sauton minimal media to early stationary phase (OD580 = 2 and 4)