Project description:SIGLEC15 in tumor microenvironment could dampen cytotoxic functions of T cells, and we blocked SIGLEC15 with mono-antibody to examine functional changes of cell populations in comparison to treatment of IgG.
Project description:The ADAR RNA editing enzymes deaminate adenosine bases to inosines in cellular RNAs, recoding open reading frames. Human ADAR1 mutations cause Aicardi-Goutieres Syndrome (AGS) and Adar1 mutant mice showing an aberrant interferon response and death by embryonic day E12.5 model the human disease. Searches have not identified key ADAR1 RNA editing sites recoding immune/haematopoietic proteins but editing is widespread in Alu sequences. We show that Adar1 embryonic lethality is rescued in Adar1; Mavs double mutant mice in which general antiviral responses to cytoplasmic dsRNA are prevented. We propose that inosine bases are epigenetic marks identifying cellular RNA as innate immune ÒselfÓ. Consistent with this idea we show that an editing-active cytoplasmic ADAR is required to prevent aberrant immune responses in Adar1 mutant mouse embryo fibroblasts. No dramatic increase in repetitive transcripts is observed. AGS mutations in ADAR1 affect editing by the interferon-inducible cytoplasmic ADAR1 isoform. RNA-seq expression profiling in Adar1 and Adar1/Mavs knockout mice embryos.
Project description:Recent studies have demonstrated critical roles for TBK1 in regulation of activity of numerous immune cell types, including T cells, B cells, dendritic cells, and macrophages. To examine the effect of TBK1 inhibition on the tumor immune microenvironment, we performed scRNA-seq on CD45+ cells from B16-OVA tumors from mice treated with anti-PD-1, TBK1i, or anti-PD-1 plus TBK1i, compared to isotype control (IgG).
Project description:RNA editing generates modifications to RNA sequences, thereby increasing protein diversity and shaping various layers of gene regulation. Recent studies have revealed global shifts in editing levels across many cancer types, as well as a few specific mechanisms implicating individual sites in tumorigenesis or metastasis. However, most tumor-associated sites, predominantly in noncoding regions, have unknown functional relevance. Here, we carry out integrative analysis of RNA editing profiles between epithelial (E) and mesenchymal (M) tumors, since epithelial-mesenchymal transition (EMT) is a key paradigm for metastasis. We identify distinct editing patterns between E and M tumors in seven cancer types using TCGA data, an observation further supported by single-cell RNA-seq data and ADAR perturbation experiments in cell culture. Through computational analyses and experimental validations, we show that differential editing sites between E and M phenotypes function by regulating mRNA abundance of their respective genes. Our analysis of >120 RNA-binding proteins revealed ILF3 as a potential regulator of this process, supported by experimental validations. Consistent with the known roles of ILF3 in immune response, E-M differential editing sites are enriched in genes involved in immune and viral processes. The strongest target of editing-dependent ILF3 regulation is the transcript encoding PKR, a crucial player in immune and viral response. Our study reports widespread differences in RNA editing between epithelial and mesenchymal tumors and a novel mechanism of editing-dependent regulation of mRNA abundance. It reveals the broad impact of RNA editing in cancer and its relevance to cancer-related immune pathways.
Project description:Our preliminary data from unbiased analyses of both ESCC patient samples and cell lines identified interferon-γ (IFN-γ) signaling pathway as the most significantly enriched pathways suppressed by TP63. To validate the activation of IFN pathways and the immune responses upon silencing of TP63, we utilized immune-competent mice to conduct allograft experiments. To analyze the effect of TP63 on ESCC tumor microenvironment, resected tumors were then collected to perform scRNA-seq.
Project description:Fibroblasts hold pivotal roles in tissue homeostasis and disease progression. However, a systematic study addressing the functional heterogeneity of fibroblasts, their dynamic shifts along disease progression, as well as their impact to tumor immune microenvironment is currently lacking. Here, we performed integrated analyses on fibroblasts spanning multiple tissues and disease conditions, especially cancer. Our study provides novel insights into fibroblast cell heterogeneity and highlights the potential clinical utilities of fibroblast cell subsets as therapeutic targets.
Project description:Using single-cell RNA-sequencing (scRNA-seq), we characterize diverse immune cell infiltrates that remodel the tissue microenvironment following senescence activation in female Znrf3 cKO mice.