Project description:Bacille Calmette Guerin (BCG) is the only licensed vaccine against Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) disease. However, BCG has limited efficacy, necessitating the development of better vaccines. Non-tuberculous mycobacteria (NTM), a distinct lineage from Mtb, are opportunistic pathogens present in the environment. TB endemic countries experience higher exposure to NTM, but previous studies have not elucidated the relationship between NTM exposure and BCG efficacy. Therefore, we developed a mouse model (BCG+NTM) that mimics human BCG vaccination at an early stage and continuous NTM exposure via the oral route, including during TB infection. Our results show that BCG+NTM mice had improved protection against pulmonary TB correlating with increased pulmonary influx of B-cells, higher titers of anti-Mtb IgA and IgG antibodies in serum and airways, compared to mice vaccinated with BCG alone. Notably, the lungs of BCG+NTM mice developed B-cell aggregates expressing markers of germinal center formation as determined by spatial transcriptomics. We conclude a direct correlation between NTM exposure and protection from TB, with B-cells playing a crucial role.
Project description:Mechanistic Insights. Our study reveals the crucial role of gammadelta T cells in non-tuberculous mycobacteria (NTM) infection. We observed a significant increase and activation of gammadelta T cells in mice infected with MAB or with MAB infection combined with pulmonary fibrosis. Depletion of gammadelta T cells worsened the infection, while transfer of gammadelta T cells reversed this effect. Mechanistically, we found that MAB infection stimulates macrophages to produce IL-1beta and IL-23, which promotes the expansion of gammadelta T17 cells. MAB can also directly activate gammadelta T cells, leading to the clearance of MAB through an IL-17A-dependent pathway. Our findings suggest that gammadelta T cells represent a potential therapeutic target for NTM infections.
Project description:Mechanistic Insights. Our study reveals the crucial role of gammadelta T cells in non-tuberculous mycobacteria (NTM) infection. We observed a significant increase and activation of gammadelta T cells in mice infected with MAB or with MAB infection combined with pulmonary fibrosis. Depletion of gammadelta T cells worsened the infection, while transfer of gammadelta T cells reversed this effect. Mechanistically, we found that MAB infection stimulates macrophages to produce IL-1beta and IL-23, which promotes the expansion of gammadelta T17 cells. MAB can also directly activate gammadelta T cells, leading to the clearance of MAB through an IL-17A-dependent pathway. Our findings suggest that gammadelta T cells represent a potential therapeutic target for NTM infections.
Project description:Detection of species-specific proteotypic peptides for accurate and easy characterization of infectious non-tuberculous mycobacteria such as Mycobacterium avium subsp. paratuberculosis, Mycobacterium marinum and Mycobacterium vaccae is essential. Therefore, we carried out reanalysis of publicly available M. avium subsp. paratuberculosis, M. marinum and M. vaccae proteomic dataset PXD027444, PXD003766 and PASS00954 by proteome database search and followed by spectral library generation. The raw DDA data were searched against their respective reference proteome databases using Proteome Discoverer and FragPipe. The resulting peptide spectrum matches were converted into a spectral library using BiblioSpec.