Project description:We used whole bodies of four different adult fire ant morphs (alate queens, workers, haploid males, and diploid males) from a single polygyne colony to generate single-base resolution DNA methylation maps. DNA was extracted from whole bodies of individual males, individual queens, and pooled workers. Bisulfite conversion and sequencing was performed by Beijing Genomics Institute (Shenzhen, China). Unmethylated enterobacteria phage lambda DNA (GenBank accession: J02459.1) was added to each genomic DNA sample as a control for bisulfite conversion efficiency.
Project description:Aspergillus flavus first gained scientific attention for its production of aflatoxin, the most potent naturally occurring toxin and hepatocarcinogenic secondary metabolite. For several decades, The DNA methylation status of A. flavus remains to be controversial. We first applied bisulfite sequencing, the gold standard at present, in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Our results reveal that the DNA methylation level of this fungus turns out to be negligible, comparable to the unmethylated lambda DNA we set as the false positive control of our bisulfite experiments. When comparing the DNA methyltransferase homolog of A. flauvs with that from several selected hypermethylated speices, we find that the DNA methyltransferase homolog of A.flavus as well as the other Aspergillus members groups closely with the RID from Neurospora crassa and Masc1 from Ascobolus immerses, which has been reported as DMT-incapable, but it diverges distantly from the other capable DNA methyltransferases. We observe significant depletion of repeat components within the A. flavus, which may possibly explain the lack of DNA methylation in this fungus. What's more, the RIP-index of the repeat of A. flavus turns out to be higher than the fungi without RID-like enzyme, suggesting this asexual fungus may possibly possess RIP process during the obscure sexual-stage which is very evanescent and may potentially related to DNA methylation. This work contributes to our understanding on the DNA methylation status of A. flavus. Also, it reinforces our views on the DNA methylation in fungal species. What's more, our strategy of applying bisulfite sequencing to DNA methylation detection on species with low DNA methylation may serve as a reference for later scientific investigations on other hypomethylated species. Two replicates were subjected to bisulfite conversion independently, unmethylated lambda DNA as a false positive control is added to both replicates.
Project description:Reads from massively parallel sequencing of RNA primed, short nascent strands from asynchronously growing cancer cells (K562, MCF7). Newly replicated DNA was isolated based on size (400-800 bp) and the presence of a short RNA stretch at the 5' end using lambda exonuclease. Purified nascent strands were analyzed using massively parallel sequencing. Sheared genomic DNA was sequenced as a control.
Project description:Strict regulation of proliferation is vital for development, whereas unregulated cell proliferation is a fundamental characteristic of cancer. The polarity protein atypical protein kinase C lambda/iota (aPKC lambda) is associated with cell proliferation through unknown mechanisms. In endothelial cells, suppression of aPKC lambda impairs proliferation despite hyperactivated mitogenic signaling. Here we show that aPKC lambda phosphorylates the DNA binding domain of forkhead box O1 (FoxO1) transcription factor, a gatekeeper of endothelial growth. Although mitogenic signaling excludes FoxO1 from the nucleus, consequently increasing c-Myc abundance and proliferation, aPKC lambda controls c-Myc expression via FoxO1/miR-34c signaling without affecting its localization. We find this pathway is strongly activated in the malignant vascular sarcoma, angiosarcoma, and aPKC inhibition reduces c-Myc expression and proliferation of angiosarcoma cells. Moreover, FoxO1 phosphorylation at Ser218 and aPKC expression correlates with poor patient prognosis. Our findings may provide a new therapeutic strategy for treatment of malignant cancers, like angiosarcoma.
Project description:Interferons (IFNs) induced early after SARS-CoV-2 infection are crucial for shaping immunity and preventing severe COVID-19. We previously demonstrated that injection of pegylated interferon-lambda1 (PEG-IFN-λ) accelerated viral clearance in COVID-19 patients. To determine if the viral decline was mediated by enhanced immunity, we assessed in vivo responses to PEG-IFN-λ by single cell RNA sequencing and measured SARS-CoV-2-specific T cell and antibody responses between placebo and PEG-IFN-λ-treated patients. PEG-IFN-λ treatment induced interferon stimulated genes in peripheral immune cells expressing IFNLR1, including plasmacytoid dendritic cells and B cells. PEG-IFN-λ did not affect SARS-CoV-2-specific antibody levels or the magnitude of virus-specific T cells. However, we identified delayed T cell responses in older adults, suggesting that PEG-IFN-λ can overcome delays in adaptive immunity to accelerate viral clearance in high-risk patients. Altogether, PEG-IFN-λ offers an early COVID-19 treatment option for outpatients to boost innate antiviral defenses without dampening peripheral adaptive immunity.
Project description:B cells positive for Ig kappa and Ig lambda are observed by flow cytometry in one fourth of patients with Systemic Lupus Erythematosus (SLE). Single cell Ig VDJ sequencing (10X Genomics) reveals that kappa/lambda B cells are at the same frequency (about 1.5%) in these SLE patients as in healthy controls. Cells observed by flow cytometry are instead decorated with VH4-34 IgM (kappa or lambda) autoantibodies that are present in some but not all SLE patients.
Project description:In this study, we characterised the interactomes of PAXX and its paralogs, XLF and XRCC4, to show that these factors share the ability to interact with DNA polymerase lambda (Poll), stimulate its activityand are required for the recruitment of Poll to laser-induced DNA damage sites.
Project description:Here we present Ultra-Mild Bisulfite Sequencing (UMBS-seq), which minimizes DNA damage and background noise while detecting 5-methylcytosine (5mC) in DNA. When applied to low-input lambda DNA (5 ng-10 pg), UMBS-seq achieved superior library yields, insert sizes, conversion efficiency, and CpG coverages compared to enzymatic alternatives. These results were recapitulated with low-input cell-free DNA (cfDNA) and in combination with targeted capture, highlighting the potential of UMBS-seq for future disease diagnosis.
Project description:Type III interferons (IFN-λ) are antiviral and immunomodulatory cytokines that have been best characterized in respiratory and gastrointestinal infections, but the effects of IFN-λ against skin infections have not been extensively investigated. We sought to define the skin-specific effects of IFN-λ against the highly prevalent human pathogen herpes simplex virus (HSV). We infected mice lacking the IFN-λ receptor (Ifnlr1-/-), both the IFN-λ and the IFN-αβ receptor (Ifnar1-/- Ifnlr1-/-), or IFN-λ cytokines (Ifnl2/3-/-) and found that IFN-λ restricts the severity of HSV-1 and HSV-2 skin lesions, independent of a direct effect on viral load. Using conditional knockout mice, we found that IFN-λ signaling in both keratinocytes and neutrophils was necessary to control HSV-1 skin lesion severity, and that IFN-λ signaling in keratinocytes suppressed CXCL9-mediated neutrophil recruitment to the skin. Furthermore, depleting neutrophils prevented the development of severe HSV-1 skin lesions in Ifnlr1-/- mice. Altogether, our results suggest that IFN-λ plays an immunomodulatory role in the skin that restricts neutrophil-mediated pathology during HSV infection, and suggest potential applications for IFN-λ in treating viral skin infections.