Project description:Functional impairment of the immune response to chronic viral infections and malignancies is characterised by exhausted T cells, which do not respond to antigen. The cell surface receptor PD1 has been implicated in the maintenance of T cell exhaustion and is an attractive target for immunomodulatory approaches to the treatment of such conditions. However, the mechanisms by which PD1 signalling causes exhaustion and the exact response of T cells to PD1 activation are not clear although it has been suggested that PD1 up regulates a number of anti-proliferative factors. Here we perform cytokine and transcriptional profiling of uninfected primary human T cells to characterise these events. We find that PD1 completely prevents cytokine and transcrip- tional changes induced by CD3/28 stimulation. We do not see any factors specifically induced by PD1, including BATF or IL10 which have previously been linked to PD1 activity. Together with the work of others this confirms that PD1 is the sole effector of T cell exhaustion and that infection is responsible for BATF and IL10 up regulation. As a consequence future therapeutic strategies will be confined to the inhibition of PD1 and not a downstream effector.
Project description:In this study, two accessions of Arabidopsis thaliana (Columbia and Landsberg erecta) were crossed and tetrads were obtained using thanks to the the quartet mutation, which keeps the 4 haploid pollen grains from a single meiosis attached together. By fertilising a plant (of ecotype Columbia) with a single tetrad, then selecting seeds from siliques containing exactly four seeds and finally sequencing the 4 developed plants, we can access the complete history of meiotic recombination events occurring in a single male meiosis. Comparison of the genomic sequences (WGS) of the 4 plants in a tetrad makes it possible to identify meiotic COs and NCOS events in each tetrad thanks to the numerous polymorphisms specific to each of the parental genomes. The analysis of the WGS tetrads data consists of genotyping a series of SNV markers (differentiating Columbia and Landsberg) positioned on the five chromosomes for the 4 (M1, M2, M3, M4) individuals of a tetrad, representing the 4 chromatids of each chromosomes. A total of 20 tetrads, the F1 and the two parental accessions Columbia and Landsberg erecta were sequenced.
Project description:The cell surface receptor programmed death 1 (PD1) is a major target for antibody-based cancer immunotherapies. An improved understanding of intracellular pathways targeted by PD1 is needed to develop better predictive and prognostic biomarkers. Here, via unbiased phosphoproteome analysis of primary human T cells, we demonstrate that PD1 triggering reduces the phosphorylation and physical association with PKC theta of a variety of cytoskeletal proteins. TCR-induced phosphorylation of Vimentin, a cytoskeleton protein identified as a PKC theta target and binding partner in our study, was found to be long-lasting and durably inhibited by PD1 triggering, and Vimentin phosphorylation inversely correlated with PDL1 levels in intratumoral T cells in human lung carcinoma. Thus, PKCθ and its substrate Vimentin represent important targets of PD1-mediated T cell inhibition and low levels of Vimentin phosphorylation could be considered as a biomarker indicating PD1 pathway engagement.
Project description:Chronic myeloid leukemia (CML) epitomizes successful targeted therapy, with 86% of patients in the chronic phase treated with tyrosine kinase inhibitors (TKIs) attaining remission. However, resistance to TKIs occurs during treatment, and patients with resistance to TKIs progress to the acute phase called Blast Crisis (BC), wherein the survival is restricted to 7-11 months. About 80 % of patients in BC are unresponsive to TKIs. This issue can be addressed by identifying a molecular signature which can predict resistance in CML-CP prior to treatment as well as by delineating the molecular mechanism underlying resistance. Herein, we report genomic analysis of CML patients and imatinib-resistant K562 cell line to achieve the same. WGS was performed on imatinib-sensitive and -resistant K562 cells. Library preparation was done by 30x WGS KAPA PCR-Free v2.1 kit, and Illumina HiSeq X sequencer was used for 2 x 150 bp paired-end sequencing. Our study identified accumulation of aberrations on chromosomes 1, 3, 7, 16 and 22 as predictive of occurrence of resistance. Further, recurrent amplification in chromosomal region 8q11.2-12.1 was detected in highly resistant K562 cells as well as CML patients. The genes present in this region were analyzed to understand molecular mechanism of imatinib resistance.
Project description:We evaluated linked-read whole genome sequencing (WGS) for detection of structural chromosomal rearrangements in primary samples of varying DNA quality from 12 patients diagnosed with ALL. Linked-read WGS enabled precise, allele-specific, digital karyotyping at a base-pair resolution for a wide range of structural variants including complex rearrangements, aneuploidy assessment and gene deletions. Additional RNA-sequencing and copy number aberrations (CNA) data from Illumina Infinium arrays were also generated and assessed against the linked-read WGS data. RNA-sequencing data was used to support structural chromosomal rearrangements detected in the linked-read WGS data by detecting expressed fusion genes as a consequence of the rearrangements. Illumina Infinium arrays (450k array and/or SNP array) were used to assess CNA status to further support the findings in the linked-read WGS data. The processed CNA data from the primary ALL patient samples has been deposited to GEO. RNA-sequencing, linked-read WGS data, and raw SNP array data from the primary ALL patient samples will not be deposited because the patient/parent consent does not cover depositing data that may be used for large-scale determination of germline variants in a repository. The ALL samples were collected 10-20 years ago from pediatric patients aged 2-15 years, some whom have deceased. The linked-read WGS data and the RNA-sequencing data sets generated in the study are available upon reasonable request from the corresponding author Jessica.Nordlund@medsci.uu.se.
Project description:We evaluated linked-read whole genome sequencing (WGS) for detection of structural chromosomal rearrangements in primary samples of varying DNA quality from 12 patients diagnosed with ALL. Linked-read WGS enabled precise, allele-specific, digital karyotyping at a base-pair resolution for a wide range of structural variants including complex rearrangements, aneuploidy assessment and gene deletions. Additional RNA-sequencing and copy number aberrations (CNA) data from Illumina Infinium arrays were also generated and assessed against the linked-read WGS data. RNA-sequencing data was used to support structural chromosomal rearrangements detected in the linked-read WGS data by detecting expressed fusion genes as a consequence of the rearrangements. Illumina Infinium arrays (450k array and/or SNP array) were used to assess CNA status to further support the findings in the linked-read WGS data. The processed CNA data from the primary ALL patient samples has been deposited to GEO. RNA-sequencing, linked-read WGS data, and raw SNP array data from the primary ALL patient samples will not be deposited because the patient/parent consent does not cover depositing data that may be used for large-scale determination of germline variants in a repository. The ALL samples were collected 10-20 years ago from pediatric patients aged 2-15 years, some whom have deceased. The linked-read WGS data and the RNA-sequencing data sets generated in the study are available upon reasonable request from the corresponding author Jessica.Nordlund@medsci.uu.se.
Project description:We evaluated linked-read whole genome sequencing (WGS) for detection of structural chromosomal rearrangements in primary samples of varying DNA quality from 12 patients diagnosed with ALL. Linked-read WGS enabled precise, allele-specific, digital karyotyping at a base-pair resolution for a wide range of structural variants including complex rearrangements, aneuploidy assessment and gene deletions. Additional RNA-sequencing and copy number aberrations (CNA) data from Illumina Infinium arrays were also generated and assessed against the linked-read WGS data. RNA-sequencing data was used to support structural chromosomal rearrangements detected in the linked-read WGS data by detecting expressed fusion genes as a consequence of the rearrangements. Illumina Infinium arrays (450k array and/or SNP array) were used to assess CNA status to further support the findings in the linked-read WGS data. The processed CNA data from the primary ALL patient samples has been deposited to GEO. RNA-sequencing, linked-read WGS data, and raw SNP array data from the primary ALL patient samples will not be deposited because the patient/parent consent does not cover depositing data that may be used for large-scale determination of germline variants in a repository. The ALL samples were collected 10-20 years ago from pediatric patients aged 2-15 years, some whom have deceased. The linked-read WGS data and the RNA-sequencing data sets generated in the study are available upon reasonable request from the corresponding author Jessica.Nordlund@medsci.uu.se.
Project description:In principle, whole-genome sequencing (WGS) of the human genome even at low coverage offers higher resolution for genomic copy number variation (CNV) detection compared to array-based technologies, which is currently the first-tier approach in clinical cytogenetics. There are, however, obstacles in replacing array-based CNV detection with that of low-coverage WGS such as cost, turnaround time, and lack of systematic performance comparisons. With technological advances in WGS in terms of library preparation, instrument platforms, and data analysis algorithms, obstacles imposed by cost and turnaround time are fading. However, a systematic performance comparison between array and low-coverage WGS-based CNV detection has yet to be performed. Here, we compared the CNV detection capabilities between WGS (short-insert, 3kb-, and 5kb-mate-pair libraries) at 1X, 3X, and 5X coverages and standardly used high-resolution arrays in the genome of 1000-Genomes-Project CEU genome NA12878. CNV detection was performed using standard analysis methods, and the results were then compared to a list of Gold Standard NA12878 CNVs distilled from the 1000-Genomes Project. Overall, low-coverage WGS is able to detect drastically more (approximately 5 fold more on average) Gold Standard CNVs compared to arrays and is accompanied with fewer CNV calls without secondary validation. Furthermore, we also show that WGS (at ≥1X coverage) is able to detect all seven validated deletions larger than 100 kb in the NA12878 genome whereas only one of such deletions is detected in most arrays. Finally, we show that the much larger 15 Mbp Cri-du-chat deletion can be clearly seen at even 1X coverage from short-insert WGS.
Project description:We performed shallow whole genome sequencing (WGS) on circulating free (cf)DNA extracted from plasma or cerebrospinal fluid (CSF), and shallow WGS on the tissue DNA extracted from the biopsy in order to evaluate the correlation between the two biomaterials. After library construction and sequencing (Hiseq3000 or Ion Proton), copy number variations were called with WisecondorX.