Project description:Due to low numbers and poor accessibility of host cells that are targeted for effector delivery, the actual biological functions of most effectors remain elusive. Here, we developed a novel Isolation Nuclei TArgeted by Bacterial Effectors (INTABE) system, which facilitates selectively recovering nuclei of the cells in Arabidopsis thaliana plants that have received type-III effectors of pathogenic Xanthomonas bacteria. Using these nuclei as studying materials, we analysed changes in host gene expression and their correlation with changes in DNA methylation induced by Xanthomonas effector Outer Protein D (XopD).
Project description:ntroduction: Recent studies have discovered lung cancer subtypes to have their own profile of microbiome within the tumor microenvironment. Additionally, the tumor associated microbiome exhibited altered bacterial pathways, suggesting that certain bacterial families are more fit to facilitate tumor progression than others. We believe that there exists a crosstalk between lung adenocarcinoma cells (LUAD) and bacterial cells. Methods and Materials: RNA-seq was performed on LUAD cell lines to understand the paracrine signaling effects that bacterial biomolecules have. From our RNA-seq data, we chose to investigate glycolysis by measuring glucose uptake and lactate production, investigate invasive potential through invasion assays, and measure EMT markers. As lipopolysaccharides (LPS) are found abundantly on the cell wall of gram-negative bacteria and can activate toll like receptor 4 (TLR4), we inhibited TLR4 with C34 to determine the relationship between TLR4 and the phenotypic changes. Finally, to gain a better understanding of the bacterial biomolecules leading to the changes observed, we treated our media with either RNAse, charcoal, or dialyzed molecules > 3kDa. Results and Discussion: From our RNA-seq data, we observed a total of 948 genes upregulated in the presence of E. coli biomolecules. Of the 948 upregulated genes observed in LUAD cell lines incubated in E. coli biomolecules, we witnessed increased expression of Hexokinase II, JUN proto-oncogene, and Snail Family Transcriptional Repressor 1. We verified the elevation of glycolytic enzymes through western blot and saw elevation of 2-deoxyglucose uptake and lactate production in LUAD cell lines incubated in E. coli biomolecules using scintillation counter and lactate luminescence assay, respectively. In addition to E. coli elevating glycolysis in LUAD cell lines, we also saw increase in invasive potential by Boyden chamber. Inhibition of TLR4 did not lead to decreasing the impact of E. coli biomolecules on glycolysis or invasive potential of LUAD. Modulating our E. coli supplemented media with either RNAse, dextran-coated charcoal, or using a spin column to remove biomolecules < 3kDa resulted in changes in HKII and Claudin protein expression. Overall, these findings indicate a direct relationship between E. coli and LUAD, wherein several well-known hallmarks of cancer are upregulated. Future studies would do well in investigating these molecules further and fully understanding the impact of a microbial shift in the tumor microenvironment.
Project description:Due to low numbers and poor accessibility of host cells that are targeted for effector delivery, the actual biological functions of most effectors remain elusive. Here, we developed a novel Isolation Nuclei TArgeted by Bacterial Effectors (INTABE) system, which facilitates selectively recovering nuclei of the cells in Arabidopsis thaliana plants that have received type-III effectors of pathogenic Xanthomonas bacteria. Using these nuclei as studying materials, we analysed changes in host gene expression and their correlation with changes in DNA methylation induced by Xanthomonas effector Outer Protein D (XopD).
Project description:Adeno-associated viruses (AAVs) are foundational gene delivery tools for basic science and clinical therapeutics. However, lack of mechanistic insight, especially for engineered vectors created by directed evolution, can hamper their application. Here, we adapted an unbiased human cell microarray platform to determine the extracellular and cell surface interactomes of natural and engineered AAVs. We identified a naturally-evolved and serotype-specific interaction of AAV9 with human interleukin 3 (IL3), with possible roles in host immune modulation, as well as lab-evolved low-density-lipoprotein-receptor-related-protein 6 (LRP6) interactions specific to engineered capsids that cross the blood-brain barrier in non-human primates upon intravenous administration. The unbiased cell microarray screening approach also allowed us to identify off-target tissue binding interactions of engineered brain-enriched AAVs that may inform vectors’ peripheral organ tropism and side effects. These results allow confident application of engineered AAVs in diverse organisms and unlock future target-informed engineering of improved viral and non-viral vectors for non-invasive therapeutic delivery to the brain.
Project description:Somatostatin receptor 2 (SSTR2) is overexpressed in neuroendocrine tumors (NETs) and meningiomas. The objective of this study was to develop an SSTR2-targeted therapy to treat both tumor types. We engineered and humanized an anti-SSTR2 monoclonal antibody (mAb) demonstrating strong cancer cell binding, internalization in cancer cells, and tumor specificity, as evidenced by flow cytometry, confocal microscopy, and live-animal imaging. Antibody-drug conjugates (ADCs) were generated by conjugating the SSTR2 mAb with potent payloads, including monomethyl auristatin F (MMAF) or mertansine (DM1). In vitro assessments revealed high cytotoxicity across diverse NET subtypes and meningioma cell lines. In vivo efficacy was confirmed in two mouse models, i.e. subcutaneous NET xenografts and intracranial meningioma xenografts, where treatment inhibited proliferation, induced apoptosis and cell death, exhibited minimal toxicity, and extended survival. The mechanism of action was further elucidated through bulk RNA sequencing post-treatment. These findings highlight the therapeutic potential of our humanized SSTR2 mAb for targeted payload delivery in NETs and meningiomas.
Project description:Directed evolution in mammalian cells can facilitate the engineering of mammalian-compatible biomolecules and can enable synthetic evolvability for mammalian cells. We engineered an orthogonal alphaviral RNA replication system to evolve synthetic RNA-based devices, enabling RNA replicase-assisted continuous evolution (REPLACE) in live mammalian cells. Toinvestigatetheexpressionheterogeneityofself-replicatingRNAsinrepRNA-v4cells,weperformedsingle-cellRNA-seqanalysisusingthe10xGenomicssequencingmethod.Ouranalysisofthesingle-cellRNA-seqprofilingdatarevealedarelativelyuniformexpressionpatternofself-replicatingRNAswithinrepRNA-v4cells.
Project description:Antibody-based therapeutics encompass diverse modalities for targeting tumor cells, among which antibody-drug conjugates (ADCs) and extracellular targeted protein degradation (eTPD) specifically depend on efficient lysosomal trafficking for activity. However, many tumor antigens exhibit poor internalization, limiting ADC effectiveness. To address this, we developed low-density lipoprotein receptor-targeting chimeras (LIPTACs), leveraging the constitutive endocytic and recycling activity of the low-density LDLR to enhance lysosomal delivery. LIPTACs enable robust degradation of diverse extracellular membrane proteins, including neo-epitopes on RAS-driven cancer cells. Moreover, by coupling LIPTACs with cytotoxic payloads to generate degrader-drug conjugates, we achieve superior intracellular delivery and enhanced cytotoxicity compared to conventional ADCs.
Project description:Lysosome-targeting chimeras (LYTACs) are a promising therapeutic modality to drive the degradation of extracellular proteins. However, early versions of LYTAC contain synthetic glycopeptides that cannot be genetically encoded. Here we present our designs for a fully genetically encodable LYTAC (GELYTAC), making our tool compatible with integration into therapeutic cells for targeted delivery at diseased sites. To achieve this, we replaced the glycopeptide portion of LYTACs with the protein insulin like growth factor 2 (IGF2). After showing initial efficacy with wild type IGF2, we increased the potency of GELYTAC using directed evolution. Subsequently, we demonstrated that our engineered GELYTAC construct not only secretes from HEK293T cells but also from human primary T-cells to drive the uptake of various targets into receiver cells. Immune cells engineered to secrete GELYTAC thus represent a promising avenue for spatially-selective targeted protein degradation.
Project description:Precisely engineering histone acylation states can inform mechanistic epigenetics and catalyze new therapeutic epigenome editing opportunities. Here, we developed engineered lysine acyltransferases that enable the deposition of acetylation and longer-chain acylations in a programmable manner using a dead Cas9 (dCas9) fusion protein. We show that targeting an engineered lysine crotonyltransferase, developed by mutagenizing the native human p300 protein, results in relatively weak levels of endogenous enhancer activation yet retains strong potency when targeted to promoters. We further identify a single mutation within the catalytic core of human p300 that preserves enzymatic activity while promoting more target-specific acetylation and substantially reducing downstream transcriptomic perturbations. Further, this novel fusion protein exhibits low cytotoxicity but maintains high levels of H3K27ac deposition, enabling markedly improved lentiviral delivery. We leveraged this enhanced delivery and improved cytotoxicity profile to perform single-cell CRISPR activation screening. Using proteomics and a panel of engineered p300 variants, we also discover acylation-specific interactions and link the cytotoxicity of the wild-type p300 core domain to altered activities among DNA repair machinery components. These new programable epigenome editing tools and insights expand our ability to perform functional genomic screens, multiplexed cell engineering, and, more broadly, understand the mechanistic role of lysine acylation in epigenetic and cellular processes.
Project description:Cance vaccines have become a milestone in immunotherapy, but inadequate activation rate of antigen presenting cells (APCs) and low delivery efficiency of specific antigen have widely limited their clinical application. Here we design an engineered vaccine platform based on targeted delivery of specific antigens to activated APCs. This vaccine platform is implemented by loading stimulator of interferon genes agonist and tumor lysate protein with calcium phosphate as adjuvants, and coating the surface with mannose-modified liposomes. By loading different types of tumor antigen proteins, this nanovaccine platform successfully achieves tumor immunotherapy in breast and colon cancer bearing mice. In addition, personalized nanovaccine prepared from surgically removed tumor lysate proteins also significantly suppresses postsurgical distant tumor. Through the design of nanovaccine platform, we provide an efficient multi-adjuvant delivery platform for multiple types of tumor antigens, and also offer more ideas for personalized vaccine immunization. This nanovaccine platform has great prospects for transformation due to the designability and simplicity for the preparation.