Project description:While immune signaling has emerged as a defining feature of the glioma microenvironment, local selection of responding T cells and their anti-tumor potential as a population are difficult to measure directly in patients. High-throughput sequencing of T cell receptor repertoires (TCRseq) provides a population-wide statistical description of how T cells respond to disease. Here, we define new immunophenotypes in glioma based on TCRseq and RNA-Seq of tumor tissue, non-neoplastic brain tissue, and peripheral blood from patients. Using information theory, we characterize antigen-driven selection in glioma and its relationship with the expression of distinct immune-functional pathways in the tumor microenvironment. Finally, we identify a strong relationship between usage of certain TCR in peripheral blood and the divergence of the infiltrating T cell population from the peripheral repertoire. We anticipate that these immunophenotypes will be foundational to monitoring and predicting response to anti-glioma vaccines and immunotherapy. We characterized the T cell receptor (TCR) repertoires of 11 high-grade glioma patients, three low-grade glioma patients, and thee non-glioma patients by TCRseq of brain-infiltrating T cells and matching peripheral blood. In addition, we obtained gene expression profiles from brain tissue of each patient by RNA-Seq. We additionally measured the TCR repertoires exclusively from peripheral blood of one additional non-glioma patient.
Project description:We dissect HCV imprinting of B cell repertoires in patients with chronic disease. The persistent character of the oncogenic B cell repertoire generated by HCV may point to a chronically elevated lymphoma risk in these patients even years after HCV cure.
Project description:Here, by using mass spectrometry-based methods IgG1 and IgA1 clonal repertoires were monitored quantitatively and longitudinally in more than 50 individual serum samples obtained from 17 COVID-19 patients admitted to intensive care units because of acute respiratory distress syndrome. These serological clonal profiles were used to examine how each patient reacted to a severe SARS-CoV-2 infection. All 17 donors revealed unique polyclonal repertoires and changes after infection. Substantial changes over time in the IgG1 and_or IgA1 clonal repertoires were observed in individual patients, with several new clones appearing following the infection, in a few cases leading to a few very high abundant IgG1 and_or IgA1 clones dominating the repertoire. Several of these clones were de novo sequenced through combinations of top-down, middle-down and bottom-up proteomics approaches. This revealed several sequence features in line with sequences deposited in the SARS-CoV-specific database of antibodies. In other patients, the serological Ig profiles revealed the treatment with tocilizumab, as after treatment, this IgG1-mAb dominated the serological IgG1 repertoire. Tocilizumab clearance could be monitored and a half-life of approximately 6 days was established in these patients. Overall, our longitudinal monitoring of IgG1 and IgA1 repertoires of individual donors reveals that antibody responses are highly personalized traits of each patient, affected by the disease and the chosen clinical treatment. The impact of these observations argues for a more personalized and longitudinal approach in patients' diagnostics, both in serum proteomics as well as in monitoring immune responses.
Project description:Genetic TNFAIP3 (A20) inactivation is a classical somatic lymphoma lesion and the genomic trait in haploinsufficiency of A20 (HA20). In a cohort of 33 HA20 patients, we show that heterozygous TNFAIP3 loss skews immune repertoires towards lymphocytes with classical self-reactive antigen receptors typically found in B and T cell lymphomas.
Project description:To study longitudinal dynamics of IGH BCR repertoires and clonal lineages evolution of memory B-cells, plasmablasts and plasma cells from peripheral blood of healthy donors, which were sampled three times within a year
Project description:Post-transcriptional modifications are important for transfer RNAs (tRNAs) to be efficient and accurate in translation on the ribosome. The m1G37 modification on a subset of tRNAs in bacteria are generated by a conserved methyltransferase TrmD and is essential for bacterial growth. Previous studies showed that m1G37 has an important role in preventing translational frameshifting and also that this modification is coupled with aminoacylation of tRNAs for proline. Here we performed suppressor screening to isolate a mutant E. coli cell that lacks TrmD but is viable, and the whole-genome sequencing revealed several mutations on prolyl-tRNA synthetase (ProRS) gene conferring cell viability in the absence of TrmD. Biochemical assays confirmed uncoupling of m1G37 modification and aminoacylation, and cell-based assays uncovered the critical role of m1G37 in supporting Wobble decoding.
Project description:Measurable residual disease (MRD) is an important biomarker in acute myeloid leukemia (AML). However, MRD cannot be detected in many patients using current methods. We developed a highly sensitive 5-hydroxymethylcytosine (5hmC) signature in cell-free DNA by analyzing 115 AML patients and 86 controls. The 5hmC method detected MRD in 20 of 29 patients with negative MRD by multiparameter flow cytometry and 11 of 14 patients with negative MRD by molecular methods. MRD detection by the 5hmC method was significantly associated with relapse-free survival. This novel method can be used in most AML patients and may significantly impact AML patient management.
Project description:The sensitivity of conventional techniques for the quantification of minimal/measurable residual disease (MRD) in chronic lymphocytic leukemia (CLL) is limited to MRD 10-4. Measuring MRD <10-4 could help to further distinguish between CLL patients with durable remission and those at risk of early relapse. We here present a novel, academically developed IGHV leader-based next-generation sequencing (NGS) assay for the quantification of MRD in CLL. We demonstrate, based on measurements in contrived MRD samples, that the linear range of detection and quantification of our novel assay reaches beyond MRD 10-5. If provided with sufficient DNA input, MRD can even be detected down to MRD 10-6. There was high inter-assay concordance between measurements of the IGHV leader-based NGS assay and allele-specific oligonucleotide quantitative PCR (r=0.92, [95%CI 0.86-0.96]) and droplet digital PCR (r=0.93, [95%CI 0.88-0.96]) on contrived MRD samples. In a cohort of 37 patients from the CLL11 trial, using MRD 10-5 as a cut-off, MRD undetectability was associated with superior progression-free survival (PFS) and time to next treatment. Importantly, deeper MRD measurement allowed for additional stratification of patients with MRD <10-4 but ≥10‑5. Whereas the PFS of these patients was significantly shorter, compared to patients with MRD <10-5 (HR 4.9, [95%CI 1.3-17.9], P=0.017), their PFS was superior to those with MRD ≥10‑4 (HR 0.18, [95%CI 0.06-0.46], P<0.001). These results clearly demonstrate the clinical utility of the novel IGHV-leader based NGS assay.