Every day Tuberculosis (TB) kills approximately three thousand people, a number that is on the rise due to the impact of the current COVID-19 pandemic on essential TB services. The causative agent... Show moreEvery day Tuberculosis (TB) kills approximately three thousand people, a number that is on the rise due to the impact of the current COVID-19 pandemic on essential TB services. The causative agent of TB, Mycobacterium tuberculosis (Mtb), is an ancient pathogen that through its evolution developed complex mechanisms to evade immune surveillance and acquired the ability to establish persistent infection in its hosts. To achieve TB eradication, the discovery of Mtb antigens that effectively correlate with the human response to infection, with the curative host response following TB treatment, and with natural as well as vaccine induced protection is critical. This thesis contributes to this ambitious aim through several findings. First, it uncovers multiple new in vivo expressed Mtb (IVE-TB) antigens by combining Mtb-transcriptomic data with advanced bioinformatics tools and medium throughput cytokine screening. Second, it deepens our understanding of the cellular and humoral immunity to Mtb antigens in latently Mtb infected donors (LTBIs) and TB patients as well as in animal models. Lastly, it demonstrates the feasibility of combining and integrating pre-clinical research of multiple mycobacterial diseases, which are endemic in the same areas and against which vaccines could induce cross-disease protection (i.e., TB and leprosy). Show less
Volkov, M.; Coppola, M.; Huizinga, R.; Eftimov, F.; Huizinga, T.W.J.; Kooi, A.J. van der; ... ; T2B Consortium 2022
The presence of autoreactive antibodies is a hallmark of many autoimmune diseases. The effector functions of (auto)antibodies are determined by their constant domain, which defines the antibody... Show moreThe presence of autoreactive antibodies is a hallmark of many autoimmune diseases. The effector functions of (auto)antibodies are determined by their constant domain, which defines the antibody isotype and subclass. The most prevalent isotype in serum is IgG, which is often the only isotype used in diagnostic testing. Nevertheless, autoantibody responses can have their own unique isotype/subclass profile. Because comparing autoantibody isotype profiles may yield new insights into disease pathophysiology, here we summarize the isotype/subclass profiles of the most prominent autoantibodies. Despite substantial variation between (and within) autoantibody responses, this unprecedented comparison shows that autoantibodies share distinctive isotype patterns across different diseases. Although most autoantibody responses are dominated by IgG (and mainly IgG1), several specific diseases are characterized by a predominance of IgG4. In other diseases, IgE plays a key role. Importantly, shared features of autoantibody isotype/subclass profiles are seen in clinically unrelated diseases, suggesting potentially common trajectories in response evolution, disease pathogenesis, and treatment response. Isotypes beyond IgG are scarcely investigated in many autoantibody responses, leaving substantial gaps in our understanding of the pathophysiology of autoimmune diseases. Future research should address isotype/subclass profiling in more detail and incorporate autoantibody measurements beyond total IgG in disease models and clinical studies. Show less
Coppola, M.; Lai, R.P.J.; Wilkinson, R.J.; Ottenhoff, T.H.M. 2021
Mycobacterium tuberculosis (Mtb) genes encoding proteins targeted by vaccines and drugs should be expressed in the lung, the main organ affected by Mtb, for these to be effective. However, the... Show moreMycobacterium tuberculosis (Mtb) genes encoding proteins targeted by vaccines and drugs should be expressed in the lung, the main organ affected by Mtb, for these to be effective. However, the pulmonary expression of most Mtb genes and their proteins remains poorly characterized. The aim of this study is to fill this knowledge gap. We analyzed large scale transcriptomic datasets from specimens of Mtb-infected humans, TB-hypersusceptible (C3H/FeJ) and TB-resistant (C57BL/6J) mice and compared data to in vitro cultured Mtb gene-expression profiles. Results revealed high concordance in the most abundantly in vivo expressed genes between pulmonary Mtb transcriptomes from different datasets and different species. As expected, this contrasted with a lower correlation found with the highest expressed Mtb genes from in vitro datasets. Among the most consistently and highly in vivo expressed genes, 35 have not yet been explored as targets for vaccination or treatment. More than half of these genes are involved in protein synthesis or metabolic pathways. This first lung-oriented multi-study analysis of the in vivo expressed Mtb-transcriptome provides essential data that considerably increase our understanding of pulmonary TB infection biology, and identifies novel molecules for target-based TB-vaccine and drug development. Show less
Coppola, M.; Jurion, F.; Eeden, S.J.F. van den; Tima, H.G.; Franken, K.L.M.C.; Geluk, A.; ... ; Ottenhoff, T.H.M. 2021
Novel tuberculosis (TB)-vaccines preferably should (i) boost host immune responses induced by previous BCG vaccination and (ii) be directed against Mycobacterium tuberculosis (Mtb) proteins... Show moreNovel tuberculosis (TB)-vaccines preferably should (i) boost host immune responses induced by previous BCG vaccination and (ii) be directed against Mycobacterium tuberculosis (Mtb) proteins expressed throughout the Mtb infection-cycle. Human Mtb antigen-discovery screens identified antigens encoded by Mtb-genes highly expressed during in vivo murine infection (IVE-TB antigens). To translate these findings towards animal models, we determined which IVE-TB-antigens are recognised by T-cells following Mtb challenge or BCG vaccination in three different mouse strains. Eleven Mtb-antigens were recognised across TB-resistant and susceptible mice. Confirming previous human data, several Mtb-antigens induced cytokines other than IFN-gamma. Pulmonary cells from susceptible C3HeB/FeJ mice produced less TNF-alpha, agreeing with the TB-susceptibility phenotype. In addition, responses to several antigens were induced by BCG in C3HeB/FeJ mice, offering potential for boosting. Thus, recognition of promising Mtb-antigens identified in humans validates across multiple mouse TB-infection models with widely differing TB-susceptibilities. This offers translational tools to evaluate IVE-TB-antigens as diagnostic and vaccine antigens. Show less
A quarter of the global human population is estimated to be latently infected by Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). TB remains the global leading cause of... Show moreA quarter of the global human population is estimated to be latently infected by Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). TB remains the global leading cause of death by a single pathogen and ranks among the top-10 causes of overall global mortality. Current immunodiagnostic tests cannot discriminate between latent, active and past TB, nor predict progression of latent infection to active disease. The only registered TB vaccine, Bacillus Calmette-Guerin (BCG), does not adequately prevent pulmonary TB in adolescents and adults, thus permitting continued TB-transmission. Several Mtb proteins, mostly discovered through IFN-gamma centered approaches, have been proposed as targets for new TB-diagnostic tests or -vaccines. Recently, however, we identified novel Mtb antigens capable of eliciting multiple cytokines, including antigens that did not induce IFN-gamma but several other cytokines. These antigens had been selected based on high Mtb gene-expression in the lung in vivo, and have been termed in vivo expressed (IVE-TB) antigens. Here, we extend and validate our previous findings in an independent Southern European cohort, consisting of adults and adolescents with either LTBI or TB. Our results confirm that responses to IVE-TB antigens, and also DosR-regulon and Rpf stage-specific Mtb antigens are marked by multiple cytokines, including strong responses, such as for TNF-alpha, in the absence of detectable IFN-gamma production. Except for TNF-alpha, the magnitude of those responses were significantly higher in LTBI subjects. Additional unbiased analyses of high dimensional flow-cytometry data revealed that TNF-alpha+ cells responding to Mtb antigens comprised 17 highly heterogeneous cell types. Among these 17 TNF-alpha+ cells clusters identified, those with CD8+TEMRA or CD8+CD4+ phenotypes, defined by the expression of multiple intracellular markers, were the most prominent in adult LTBI, while CD14+ TNF-alpha+ myeloid-like clusters were mostly abundant in adolescent LTBI. Our findings, although limited to a small cohort, stress the importance of assessing broader immune responses than IFN-gamma alone in Mtb antigen discovery as well as the importance of screening individuals of different age groups. In addition, our results provide proof of concept showing how unbiased multidimensional multiparametric cell subset analysis can identify unanticipated blood cell subsets that could play a role in the immune response against Mtb. Show less
