Project description:Plasma cell differentiation is characterized by differentiation of progenitor cells into short-lived and long-lived compartments. Here we examine how gene expression and nuclear architecture are linked to instruct short-lived and long-lived plasma cell fate. We find that plasma cell commitment is concurrent with the nuclear repositioning of transcription start sites associated with activation or repression of genes including the Irf4 and Bcl6 loci, respectively. Intergenic regions associated with the Ebf1 and Prdm1 loci also reposition concomitant with altered patterns of gene expression. Plasma cell differentiation is also enriched for inter-chromosomal associations concurrent at a global scale with alterations in gene expression. Finally, we find that the onset of plasma cell development is associated with a gain in euchromatic strength for genes encoding for cell cycle regulation and DNA repair that characterize in part the long-lived plasma cell fate. We conclude that at the onset of plasma cell development different strategies are applied to modulate genes that dictate short-lived and long-lived plasma cell gene programs.
Project description:Krüppel-like factor 2 (KLF2) is a potent regulator of lymphocyte differentiation, activation and migration. However, its functional role in adaptive and humoral immunity remains elusive. Therefore, by using mice with a B cell-specific deletion of KLF2, we investigated plasma cell differentiation and antibody responses. We revealed that the deletion of KLF2 resulted in perturbed IgA plasma cell compartmentalization, characterized by the absence of IgA plasma cells in the bone marrow, their reductions in the spleen, the blood and the lamina propria of the colon and the small intestine, concomitant with their accumulation and retention in mesenteric lymph nodes and Peyer’s patches. Most intriguingly, secretory IgA in the intestinal lumen was almost absent, dimeric serum IgA was drastically reduced and antigen-specific IgA responses to soluble Salmonella flagellin were blunted in KLF2-deficient mice. Perturbance of IgA plasma cell localization was caused by deregulation of CCR9, Integrin chains αM, α4, β7, and sphingosine-1-phosphate receptors. Hence, KLF2 not only orchestrates the localization of IgA plasma cells by fine-tuning chemokine receptors and adhesion molecules but also controls IgA responses to Salmonella flagellin.
Project description:This SuperSeries is composed of the following subset Series: GSE35777: A molecular mechanism for compartmentalization and silencing of chromatin domains at the nuclear lamina [Tiling Array] GSE36048: A molecular mechanism for compartmentalization and silencing of chromatin domains at the nuclear lamina [ChIP-seq] Refer to individual Series
Project description:Protein glycosylation, a complex and heterogeneous post-translational modification that is frequently dysregulated in disease, has been difficult to analyse at scale. Here we report a data-independent acquisition technique for the large-scale mass-spectrometric quantification of glycopeptides in plasma samples. The technique, which we named ‘OxoScan-MS’, identifies oxonium ions as glycopeptide fragments and exploits a sliding-quadrupole dimension to generate comprehensive and untargeted oxonium- ion maps of precursor masses assigned to fragment ions from non-enriched plasma samples. By applying OxoScan-MS to quantify 1,002 glycopeptide features in the plasma glycoproteomes from patients with COVID-19 and healthy controls, we found that severe COVID-19 induces differential glycosylation in IgA, haptoglobin, transferrin and other disease-relevant plasma glycoproteins. OxoScan-MS may allow for the quantitative mapping of glycoproteomes at the scale of hundreds to thousands of samples.
Project description:This is a Phase 1, single-dose, open-label, dose-escalation study. The study will be conducted in three parts (i.e. regimens) in an outpatient setting as follows:
* Regimen A: FATE-NK100 as a monotherapy in subjects with advanced solid tumor malignancies.
* Regimen B: FATE-NK100 in combination with trastuzumab in subjects with human epidermal growth factor receptor 2 positive (HER2+) advanced breast cancer, HER2+ advanced gastric cancer or other advanced HER2+ solid tumors.
* Regimen C: FATE-NK100 in combination with cetuximab in subjects with advanced colorectal cancer (CRC) or head and neck squamous cell cancer (HNSCC), or other epidermal growth factor receptor 1 positive (EGFR1+) advanced solid tumors.
Project description:Germ cells manifest a unique gene expression program and regain totipotency in the zygote. Here, we perform Hi-C analysis to examine 3D chromatin organization in male germ cells during spermatogenesis. We show that the highly compartmentalized 3D chromatin organization characteristic of interphase nuclei is attenuated in meiotic prophase. Meiotic prophase is predominated by short-range intrachromosomal interactions that represent a condensed form akin to that of mitotic chromosomes. However, unlike mitotic chromosomes, meiotic chromosomes display weak genomic compartmentalization, weak topologically associating domains, and localized point interactions in prophase. In postmeiotic round spermatids, genomic compartmentalization increases and gives rise to the strong compartmentalization seen in mature sperm. The X chromosome lacks domain organization during meiotic sex-chromosome inactivation. We propose that male meiosis occurs amid global reprogramming of 3D chromatin organization and that strengthening of chromatin compartmentalization takes place in spermiogenesis to prepare the next generation of life.
Project description:How gene positioning to the nuclear periphery regulates transcription remains largely unclear. We have previously observed the differential compartmentalization of transcription factors and histone modifications at the nuclear periphery in mouse C2C12 myoblasts. Here, we have integrated high throughput DNA sequencing into the DNA adenine methyltransferase identification (DamID) assay, and have identified ~15, 000 sequencing-based Lamina-Associated Domains (sLADs) in mouse 3T3 fibroblasts and C2C12 myoblasts. These genomic regions range from a few kb to over 1 Mb and cover ~30% of the genome, and are spatially proximal to the nuclear lamina (NL). Active histone modifications such as H3K4me2, H3K9Ac, H3K36me3 and H3K79me2 are all localized away from the nuclear periphery microscopically, and distributed predominantly out of sLADs genome-wide. Therefore, the spatial compartmentalization of active histone modifications likely characterizes a major portion of chromatin at the nuclear periphery in mammalian cells. Genomic regions around transcription start sites of expressed sLAD genes display reduced associations with the NL and possess active histone modifications; in contrast, gene bodies of expressed sLAD genes possess very low levels of active histone modifications. Our genome-wide analyses of NL-associated chromatin have enabled functional and mechanistic dissections of gene positioning on transcription regulation. generate DamID maps of genome-NL interaction for mouse 3T3 fibroblasts and C2C12 myoblasts
Project description:The mechanisms whereby enteric pathogens and microbes induce systemic antibody responses remain obscure. In contrast to accepted models, we show that commensal microbes have a dramatic impact on the bone marrow (BM) plasma cell pool. Unlike standard vendor mice, in mice reared in our colony the majority of long-lived BM plasma cells secreted IgA antibodies. Exposing vendor mice to a unique microflora or Helicobacter sp. led to the generation of IgA-secreting BM cells, while also inducing increases in serum IgA antibodies enriched for binding to several commensal bacterial taxa. Moreover, BM IgA-secreting plasma cells exhibited a common clonal ancestry with intestinal IgA+ plasma cells, and both populations possessed unique gene expression signatures compared to other long-lived BM plasma cells. We conclude that commensal microbes overtly influence the BM plasma cell pool, and suggest that select commensal microbes can facilitate the induction of systemic humoral immunity.