Biology subjects

Mokry, M.

Publications and source records attributed to Mokry, M..

23 records · Page 2Linked to original sources

bioRxiv2020

Conserved human effector Treg signature is reflected in transcriptomic and epigenetic landscape

Treg are critical regulators of immune homeostasis, and increasing evidence demonstrates that environment-driven Treg differentiation into effector (e)Treg is crucial for optimal functioning. However, human Treg programming under inflammatory conditions remains poorly understood. Here, we combine transcriptional and epigenetic profiling to identify the human eTreg core signature. Functional autoimmune inflammation-derived Treg display a unique transcriptional profile characterized by upregulation of both a core Treg (FOXP3, CTLA-4, TIGIT) and effector program (GITR, BLIMP-1, BATF). We identified a specific human eTreg signature that includes the vitamin D receptor (VDR) as predicted key-regulator in eTreg differentiation. H3K27ac/H3K4me1 occupancy revealed pronounced changes in the (super-)enhancer landscape, including enrichment of the binding motif for VDR and BATF. The observed Treg profile showed striking overlap with tumor-infiltrating Treg. Our data demonstrate that human inflammation-derived Treg acquire a specific eTreg profile guided by epigenetic changes. The core eTreg profile is conserved, and fine-tuned by environment-specific adaptations.

immunology↗

bioRxiv2020

Prime editing for functional repair in patient-derived disease models

Prime editing is a novel genome editing technology using fusion proteins of Cas9-nickase and reverse transcriptase, that holds promise to correct the vast majority of genetic defects. We develop prime editing for primary adult stem cells grown in organoid culture models. First, we generate precise in-frame deletions in the gene encoding {beta}-catenin (CTNNB1) that result in proliferation independent of Wnt-stimuli, mimicking a mechanism of the development of liver cancer. Moreover, prime editing functionally recovers diseasecausing mutations in intestinal organoids from patients with DGAT1-deficiency and liver organoids from a patient with Wilson disease (ATP7B). Prime editing is as efficient in 3D grown organoids as in 2D grown cell lines and offers greater precision than Cas9-mediated homology directed repair (HDR). Base editing remains more reliable than prime editing but is restricted to a subgroup of pathogenic mutations. Whole-genome sequencing of four prime-edited clonal organoid lines reveals absence of genome-wide off-target effects underscoring therapeutic potential of this versatile and precise gene editing strategy.

genomics↗

bioRxiv2020

Sex dependent gene activity in the human body

Many pathophysiological mechanisms in human health and disease are dependent on sex. Systems biology approaches are successfully used to decipher human disease etiology, yet the effect of sex on gene network biology is mostly unknown. To address this, we used RNA-sequencing data of over 700 individuals spanning 24 tissues from the Genotype-Tissue Expression project to generate a whole-body gene activity map and quantified the sex differences per tissue. We found that of the 13,787 genes analyzed in 24 tissues, 20.1% of the gene activity is influenced by sex. For example, skeletal muscle was predominantly enriched with genes more active in males, whereas thyroid primarily contained genes more active in females. This was accompanied by consistent sex differences in pathway activity, including hypoxia, epithelial-to-mesenchymal transition, and inflammation over the human body. Furthermore, multi-organ analyses revealed consistent sex-dependent gene activity over numerous tissues which was accompanied by enrichment of transcription factor binding motifs in the promoters of these genes. Finally, we show that many sex-biased genes are known druggable targets. This emphasizes sex as a biological variable and the need to incorporate sex in systems biology studies.

systems biology↗

bioRxiv2020

Genome wide association analysis in dilated cardiomyopathy reveals two new key players in systolic heart failure on chromosome 3p25.1 and 22q11.23

We present the results of the largest genome wide association study (GWAS) performed so far in dilated cardiomyopathy (DCM), a leading cause of systolic heart failure and cardiovascular death, with 2,719 cases and 4,440 controls in the discovery population. We identified and replicated two new DCM-associated loci, one on chromosome 3p25.1 (lead SNP rs62232870, p = 8.7 x 10-11 and 7.7 x 10-4 in the discovery and replication step, respectively) and the second on chromosome 22q11.23 (lead SNP rs7284877, p = 3.3 x 10-8 and 1.4 x 10-3 in the discovery and replication step, respectively) while confirming two previously identified DCM loci on chromosome 10 and 1, BAG3 and HSPB7. The genetic risk score constructed from the number of lead risk-alleles at these four DCM loci revealed that individuals with 8 risk-alleles were at a 27% increased risk of DCM compared to individuals with 5 risk alleles (median of the referral population). We estimated the genome wide heritability at 31% {+/-} 8%. In silico annotation and functional 4C-sequencing analysis on iPSC-derived cardiomyocytes strongly suggest SLC6A6 as the most likely DCM gene at the 3p25.1 locus. This gene encodes a taurine and beta-alanine transporter whose involvement in myocardial dysfunction and DCM is supported by recent observations in humans and mice. Although less easy to discriminate the better candidate at the 22q11.23 locus, SMARCB1 appears as the strongest one. This study provides both a better understanding of the genetic architecture of DCM and new knowledge on novel biological pathways underlying heart failure, with the potential for a therapeutic perspective.

genomics↗

bioRxiv2019

Human regulatory T cells at the maternal-fetal interface show functional site-specific adaptation with tumor-infiltrating-like features

ObjectivesRegulatory T cells (Tregs) are crucial for maintaining immune tolerance against the semi-allogeneic fetus during pregnancy. Since their functional profile at the human maternal-fetal interface is still elusive, we investigated the transcriptional profile and functional adaptation of human uterine Tregs (uTregs) during pregnancy.\n\nMethodsBlood and uterine biopsies from the placental bed (=maternal-fetal interface) and incision site (=control), were obtained from women with uneventful pregnancies undergoing primary Caesarean section. Tregs and CD4+ non-Tregs (Tconv) were isolated for transcriptomic profiling by Cel-Seq2. Results were validated on protein and single cell level by flow cytometry.\n\nResultsPlacental bed uterine Tregs (uTregs) showed elevated expression of Treg signature markers compared to blood Tregs, including FOXP3, CTLA4 and TIGIT. The uTreg transcriptional profile was indicative of late-stage effector Treg differentiation and chronic activation with high expression of immune checkpoints GITR, TNFR2, OX-40, 4-1BB, genes associated with suppressive capacity (CTLA4, HAVCR2, IL10, IL2RA, LAYN, PDCD1), activation (HLA-DR, LRRC32), and transcription factors MAF, PRDM1, BATF, and VDR. uTregs mirrored uTconv Th1 polarization, and characteristics indicating tissue-residency, including high CD69, CCR1, and CXCR6. The particular transcriptional signature of placental bed uTregs overlapped strongly with the specialized profile of human tumor-infiltrating Tregs, and, remarkably, was more pronounced at the placental bed than uterine control site.\n\nConclusionuTregs at the maternal-fetal interface acquire a highly differentiated effector Treg profile similar to tumor-infiltrating Tregs, which is locally enriched compared to a distant uterine site. This introduces the novel concept of site-specific transcriptional adaptation of human Tregs within one organ.

immunology↗