Project description:The century-old Mycobacterium bovis Bacillus Calmette-Guerin (BCG) remains the only licensed vaccine against tuberculosis (TB). Despite this, there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity. Here, we investigated immune responses in adult individuals pre and 8 months post BCG vaccination. We specifically determined changes in gene expression, cell subset composition, DNA methylome, and the TCR repertoire induced in PBMCs and CD4 memory T cells associated with antigen stimulation by either BCG or a Mycobacterium tuberculosis (Mtb)-derived peptide pool. Following BCG vaccination, we observed increased frequencies of CCR6+ CD4 T cells, which includes both Th1* and Th17 subsets, and mucosal associated invariant T cells (MAITs). A large number of immune response genes and pathways were upregulated post BCG vaccination with similar patterns observed in both PBMCs and memory CD4 T cells, thus suggesting a substantial role for CD4 T cells in the cellular response to BCG. These upregulated genes and associated pathways were also reflected in the DNA methylome. We described both qualitative and quantitative changes in the BCG-specific TCR repertoire post vaccination, and importantly found evidence for similar TCR repertoires across different subjects. The immune signatures defined herein can be used to track and further characterize immune responses induced by BCG, and can serve as reference for benchmarking novel vaccination strategies.
Project description:BackgroundThe century-old Mycobacterium bovis Bacillus Calmette-Guerin (BCG) remains the only licensed vaccine against tuberculosis (TB). Despite this, there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity.MethodsWe investigated immune responses in adult individuals pre and 8 months post BCG vaccination. We specifically determined changes in gene expression, cell subset composition, DNA methylome, and the TCR repertoire induced in PBMCs and CD4 memory T cells associated with antigen stimulation by either BCG or a Mycobacterium tuberculosis (Mtb)-derived peptide pool.FindingsFollowing BCG vaccination, we observed increased frequencies of CCR6+ CD4 T cells, which includes both Th1* (CXCR3+CCR6+) and Th17 subsets, and mucosal associated invariant T cells (MAITs). A large number of immune response genes and pathways were upregulated post BCG vaccination with similar patterns observed in both PBMCs and memory CD4 T cells, thus suggesting a substantial role for CD4 T cells in the cellular response to BCG. These upregulated genes and associated pathways were also reflected in the DNA methylome. We described both qualitative and quantitative changes in the BCG-specific TCR repertoire post vaccination, and importantly found evidence for similar TCR repertoires across different subjects.InterpretationThe immune signatures defined herein can be used to track and further characterize immune responses induced by BCG, and can serve as reference for benchmarking novel vaccination strategies.
Project description:The century-old Mycobacterium bovis Bacillus Calmette-Guerin (BCG) remains the only licensed vaccine against tuberculosis (TB). Despite this, there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity. Here, we investigated the BCG-specific gene expression changes induced in PBMCs and CD4 memory T cells by BCG in individuals pre- and 8m post vaccination. We also determined whether reactivity against a peptide pool defined in individuals with controlled latent TB infection (MTB300), and with peptides homologous to peptides found in BCG, was boosted following BCG vaccination.
Project description:Intravesical BCG Immunotherapy is the standard of care in treating non-muscle invasive bladder cancer, yet its mechanism of action remains elusive. Both innate and adaptive immune responses have been implicated in BCG activity. While prior research has indirectly demonstrated the importance of T cells and shown a rise in CD4+ T cells in bladder tissue after BCG, T cell subpopulations have not been fully characterized. We investigated the relationship between effector and regulatory T cells in an immune competent, clinically relevant rodent model of bladder cancer. Our data demonstrate that cancer progression in the MNU rat model of bladder cancer is characterized by a decline in the CD8/FoxP3 ratio, consistent with decreased adaptive immunity. By contrast, treatment with intravesical BCG leads to a large, transient rise in the CD4+ T cell population in the urothelium, and is both more effective and immunogenic compared to intravesical chemotherapy. Interestingly, whole transcriptome expression profiling of post-treatment intravesical CD4+ and CD8+ T cells revealed minimal differences in gene expression after BCG treatment. Together, our results suggest that while BCG induces T cell recruitment to the bladder, the T cell phenotype does not markedly change, implying that combining T cell activating agents with BCG might improve clinical activity.
Project description:In an effort to identify mechanisms governing HIV-1 permissiveness in gut-homing Th17 cells, we analyzed the transcriptome of CCR6+ versus CCR6- T-cells exposed to the gut-homing inducer retinoic acid (RA) and performed functional validations in colon biopsies of HIV-infected individuals receiving ART (HIV+ART). Together, our results identify mTOR as a druggable key regulator of HIV permissiveness in gut-homing CCR6+ T-cells.
Project description:After a century of the Bacillus Calmette-Guérin (BCG) vaccine, our understanding of its protection against homologous (Mycobacterium tuberculosis) or heterologous (e.g. influenza virus) infections is still limited. Here we show that systemic (intravenous) BCG vaccination (BCG-iv) provides significant protection against subsequent influenza A virus (IAV) infection in mice. We further demonstrate that the BCG-mediated cross-protection against IAV is largely due to the enrichment of conventional CD4+ αβ effector memory T cells that express high levels of CX3CR1hi in circulation trafficking into the lung parenchyma. Importantly, pulmonary CX3CR1hi T cells limit early viral infection in an antigen-independent manner via potent IFNγ production, which subsequently enhances long-term antimicrobial activity of the innate immune system like alveolar macrophages. Similarly, we uncover a prominent IFNγ signature in which its increased basal production was associated with enhanced BCG-mediated heterologous innate memory responses in BCG-vaccinated humans. These results offer insight into the unknown mechanism by which BCG has persistently displayed broad protection against non-tuberculous infections via a crosstalk between adaptive and innate memory responses.
Project description:To detect the miRNA expression profile in CCR6+ regulatory T cells In this study, the total RNA was extracted from CCR6+ regulatory T cells and CCR6- regulatory T cells. Then, the expression profile of miRNA on these cells was detected by microarray.
Project description:Microarray was used to determine transcriptional differences between Nr1d1+/+ CCR6+ ILC3s and Nr1d1-/- CCR6+ ILC3s isolated from small intestine lamina propria