Project description:Background Identification of patients at risk of tuberculosis relapse following treatment would revolutionize clinical trials of new drugs and regimens and facilitate clinical management. The study aim was to determine whether tuberculosis patients who subsequently suffer relapse have different immune responses to mycobacteria in vitro compared to patients who remain cured for two years post-treatment. Methods First episode pulmonary tuberculosis patients were recruited into a surrogate marker study in Cape Town, South Africa. Peripheral blood samples were collected at diagnosis and after two and four weeks of tuberculosis treatment. Diluted blood was cultured with live Mycobacterium tuberculosis for six days and cellular RNA was frozen. Gene expression in samples from ten patients who subsequently relapsed, confirmed by stain genotyping, was compared to those who remained cured using Affymetrix microarrays. Results At diagnosis, the expression of 668 genes was significantly different in samples from patients who subsequently relapsed compared to successfully cured patients, and these differences persisted for at least four weeks. Gene Ontology and biological pathways analyses revealed the most significant difference was up-regulation of genes involved in cytotoxic cell-mediated killing, such as perforin, granulysin and fas ligand. Results were confirmed by qRT-PCR in a wider patient cohort. Conclusions These data show that patients who will subsequently relapse exhibit altered immune responses at diagnosis, including excessively robust cytolytic responses to M. tuberculosis in vitro, compared to patients who will achieve durable cure. Together with microbiological and clinical indices, these differences could be exploited for patient stratification in drugs trials, or for host-directed therapy development. Venous blood samples were diluted in culture medium and stimulated with live M. tuberculosis for 6 days. Samples from 10 TB patients who subsequently relapsed and 10 patients whore remained disease-free for 2 years. Samples collected at TB diagnosis and after 2 weeks or 4 weeks of treatment of first TB episode.
Project description:Background Identification of patients at risk of tuberculosis relapse following treatment would revolutionize clinical trials of new drugs and regimens and facilitate clinical management. The study aim was to determine whether tuberculosis patients who subsequently suffer relapse have different immune responses to mycobacteria in vitro compared to patients who remain cured for two years post-treatment. Methods First episode pulmonary tuberculosis patients were recruited into a surrogate marker study in Cape Town, South Africa. Peripheral blood samples were collected at diagnosis and after two and four weeks of tuberculosis treatment. Diluted blood was cultured with live Mycobacterium tuberculosis for six days and cellular RNA was frozen. Gene expression in samples from ten patients who subsequently relapsed, confirmed by stain genotyping, was compared to those who remained cured using Affymetrix microarrays. Results At diagnosis, the expression of 668 genes was significantly different in samples from patients who subsequently relapsed compared to successfully cured patients, and these differences persisted for at least four weeks. Gene Ontology and biological pathways analyses revealed the most significant difference was up-regulation of genes involved in cytotoxic cell-mediated killing, such as perforin, granulysin and fas ligand. Results were confirmed by qRT-PCR in a wider patient cohort. Conclusions These data show that patients who will subsequently relapse exhibit altered immune responses at diagnosis, including excessively robust cytolytic responses to M. tuberculosis in vitro, compared to patients who will achieve durable cure. Together with microbiological and clinical indices, these differences could be exploited for patient stratification in drugs trials, or for host-directed therapy development.
2015-09-10 | GSE67589 | GEO
Project description:Bacterial Factors That Predict Relapse After Anti-tuberculosis Therapy
Project description:Tuberculosis-affected lungs with chronic inflammation harbor abundant immunosuppressive immune cells but the nature of such inflammation is unclear. Dysfunction in T cell exhaustion, while implicated in chronic inflammatory diseases, remains unexplored in tuberculosis. Given that immunotherapy targeting exhaustion checkpoints exacerbates tuberculosis, we speculate that T cell exhaustion is dysfunctional in tuberculosis. Using integrated single-cell RNA sequencing and T cell receptor profiling we reported defects in exhaustion responses within inflamed tuberculosis-affected lungs. Tuberculosis lungs demonstrated significantly reduced levels of exhausted CD8+ T cells and exhibited diminished expression of exhaustion-related transcripts among clonally expanded CD4+ and CD8+ T cells. Additionally, clonal expansion of CD4+ and CD8+ T cells bearing T cell receptors specific for CMV was observed. Expanded CD8+ T cells expressed the cytolytic marker GZMK. Hence, inflamed tuberculosis-affected lungs displayed dysfunction in T cell exhaustion. Our findings likely hold implications for understanding the reactivation of tuberculosis observed in patients undergoing immunotherapy targeting the exhaustion checkpoint.
Project description:Rituximab (RTX) is widely used as a first-line therapeutic strategy for patients affected by immune thrombocytopenia (ITP). However, a large proportion of patients relapse after successful treatment. The present NGS assay was done to help find the cause for this relapse on the immune repertoire level. Therefore, we performed antibody repertoire sequencing for three RTX relapse patients with subsequent mutation and clonal analysis, as well as for two patients with ongoing ITP and two healthy donors (HD) with subsequent mutation analysis.
Project description:Immunosuppressive elements within the tumor microenvironment such as Tumor Associated Macrophages (TAMs) can present a barrier to successful anti-tumor responses by cytolytic T cells. We employed preclinical syngeneic p53 null mouse models of TNBC to develop a treatment regimen that harnessed the immunostimulatory effects of low-dose chemotherapy coupled with the pharmacologic inhibition of TAMs. Combination therapy was used to successfully treat several highly aggressive, claudin-low murine mammary tumors and lung metastasis. Long-term responders developed tertiary lymphoid structures co-infiltrated by T and B cells at the treatment site. Mechanistically, CD86+ antigen-experienced T cells exhibited polyclonal expansion and resulted in exceptional responses upon tumor rechallenge. Combination treatment also eliminated lung metastases. High dimensional transcriptomic data for CD45+ immune cells lead to the identification of an aberrant developmental trajectory for TAMs that were resistant to treatment. This study illustrates the complexity of tumor infiltrating myeloid cells and highlights the importance of personalized immuno-genomics to inform therapeutic regimens
Project description:Checkpoint blockade immunotherapy has become a first-line treatment option for cancer patients, with success in increasingly diverse cancer types. Still, many patients do not experience durable responses and the reasons for clinical success versus failure remain largely undefined. Investigation of immune responses within the tumor microenvironment can be highly informative but access to tumor tissue is not always available, highlighting the need to identify biomarkers in the blood that correlate with clinical success. Here, we used single-cell RNA sequencing coupled with T cell receptor sequencing to define CD8+ T cell responses in peripheral blood of two patients with melanoma before and after immunotherapy with either anti-PD-1 (nivolumab) alone or the combination of anti-PD-1 and CTLA-4 (ipilimumab). Both treatment regimens increased transcripts associated with cytolytic effector function and decreased transcripts associated with naive T cells. These responses were further evaluated at the protein level and extended to a total of 53 patients with various cancer types. Unexpectedly, the induction of CD8+ T cell responses associated with cytolytic function was variable and did not predict therapeutic success in this larger patient cohort. Rather, a decrease in the frequency of T cells with a naive-like phenotype was consistently observed after immunotherapy and correlated with prolonged patient survival. In contrast, a more detailed clonotypic analysis of emerging and expanding CD8+ T cells in the blood revealed that a majority of individual T cell clones responding to immunotherapy acquired a transcriptional profile consistent with cytolytic effector function. These results suggest that responses to checkpoint blockade immunotherapy are evident and traceable in patients’ blood, with outcomes predicted by the simultaneous loss of naive-like CD8+ T cells and the expansion of mostly rare and diverse cytotoxic CD8+ T cell clones.
Project description:The antimicrobials isoniazid and pyrazinamide, used for the treatment of tuberculosis are known to cause drug-induced liver injury in humans. This limits the effectiveness of tuberculosis treatment, resulting in incomplete cure, relapse and the development of antimicrobial resistance. MicroRNAs are known to be good biomarkers of disease, with the microRNA miR-122 being diagnostic for liver injury. In this study zebrafish larvae were exposed to the anti-tuberculosis drugs isoniazid and pyrazinamide at concentrations which demonstrated liver injury by microscopy and histology. The aim of this study is to understand small RNA changes occurring in anti-tuberculosis drug-induced liver injury and to attempt to identify novel microRNA biomarkers of liver injury.