The applicability of cytosine base editors is hindered by their dependence on sequence context and by off-target effects. Here, by using AlphaFold2 to predict the three-dimensional structure of 1,483 cytidine deaminases and by experimentally characterizing representative deaminases (selected from each structural cluster after categorizing them via partitional clustering), we report the discovery of a few deaminases with high editing efficiencies, diverse editing windows and increased ratios of on-target to off-target effects. Specifically, several deaminases induced C-to-T conversions with comparable efficiency at AC/TC/CC/GC sites, the deaminases could introduce stop codons in single-copy and multi-copy genes in mammalian cells without double-strand breaks, and some residue conversions at predicted DNA-interacting sites reduced off-target effects.
View Article and Find Full Text PDFCurr Issues Mol Biol
April 2024
The demand for high-precision CRISPR/Cas9 systems in biomedicine is experiencing a notable upsurge. The editing system fdCas9 employs a dual-sgRNA strategy to enhance editing accuracy. However, the application of fdCas9 is constrained by the stringent requirement for two protospacer adjacent motifs (PAMs) of Cas9.
View Article and Find Full Text PDFTo expand the scope of genomic editing, a C-to-G transversion-based editor called CGBE has been developed for precise single-nucleotide genomic editing. However, limited editing efficiency and product purity have hindered the development and application of CGBE. In this study, we introduced the Puromycin-Resistance Screening System, referred to as CGBE/ABE-PRSS, to select genetically modified cells via the CGBE or ABE editors.
View Article and Find Full Text PDFThe FokI catalytic domain can be fused to various DNA binding architectures to improve the precision of genome editing tools. However, evaluation of off-target effects is essential for developing these tools. We use Genome-wide Off-target analysis by Two-cell embryo Injection (GOTI) to detect low-frequency off-target editing events in mouse embryos injected with FokI-based architectures.
View Article and Find Full Text PDFBase editors have been reported to induce off-target mutations in cultured cells, mouse embryos and rice, but their long-term effects in vivo remain unknown. Here, we develop a Systematic evaluation Approach For gene Editing tools by Transgenic mIce (SAFETI), and evaluate the off-target effects of BE3, high fidelity version of CBE (YE1-BE3-FNLS) and ABE (ABE7.10) in ~400 transgenic mice over 15 months.
View Article and Find Full Text PDFPurpose: To investigate the feasibility of immediate implantation after extraction of anterior teeth in patients with periodontal disease and its clinical effect within 2 years.
Methods: Thirty patients (36 implants) who underwent anterior dental implant treatment for periodontal disease from 2016 to 2018 were randomly divided into immediate implantation group (17 implants) and delayed implantation group (19 implants). The patients were followed up for 2 years, the clinical parameters such as periodontal probing depth, pink esthetic score(PES)and implant neck bone resorption volume of implant neck were obtained.
The suppressor of cytokine signaling 3 (SOCS3) is a major regulator of immune responses and inflammation as it negatively regulates cytokine signaling. Here, the role of SOCS3 in thymic T cell formation was studied in mice (Δ with a tamoxifen inducible and ubiquitous deficiency. Δ thymi showed a 90% loss of cellularity and altered cortico-medullary organization.
View Article and Find Full Text PDFScavenger receptors are pattern recognition receptors that recognize both foreign and self-ligands, and initiate different mechanisms of cellular activation, often as co-receptors. The function of scavenger receptor CD36 in the immune system has mostly been studied in macrophages but it is also highly expressed by innate type B cells where its function is less explored. Here we report that CD36 is involved in macro-autophagy/autophagy in B cells, and in its absence, the humoral immune response is impaired.
View Article and Find Full Text PDFW922, a novel PI3K/Akt/mTOR pathway inhibitor, exhibits efficient anti‑tumor effects on HCT116, MCF‑7 and A549 human cancer cells compared with other synthesized compounds. The present study aimed to investigate its anti‑tumor effects on colorectal cancer cells. A total, of seven different colorectal cell lines were selected to test the anti‑proliferation profile of W922, and HCT116 was found to be the most sensitive cell line to the drug treatment.
View Article and Find Full Text PDFIn systemic autoimmune diseases such as systemic lupus erythematosus (SLE), B cell tolerance is lost and there is a production of autoantibodies that drive pathology. The specificities of these antibodies are towards a wide range of autoantigens including proteins such as serum factors including cytokines as well as towards nucleic acids and modified glycolipids. It is known that endosomal pattern recognition receptors are involved in specific responses but if they drive specificity towards a specific group of autoantigens is not known.
View Article and Find Full Text PDFThe progression and metastatic capacity of solid tumors are strongly influenced by immune cells in the tumor microenvironment. In non-small cell lung cancer (NSCLC), accumulation of anti-inflammatory tumor-associated macrophages (TAM) is associated with worse clinical outcome and resistance to therapy. Here we investigated the immune landscape of NSCLC in the presence of protumoral TAMs expressing the macrophage receptor with collagenous structure (MARCO).
View Article and Find Full Text PDFMarginal zone (MZ) B cells are innate-like B cells that produce polyreactive antibodies with an affinity for microbial molecular patterns and carbohydrate ligands. MZ B cells have been shown to be important in mediating immunity to various bacteria including Streptococcus pneumoniae and are also implicated in inflammatory syndromes including lupus erythematosus. The intestinal microbiota is responsible for producing short-chain fatty acids, which can regulate immune cell function by several mechanisms including ligation of the G-protein-coupled receptor (GPR)43.
View Article and Find Full Text PDF() is an important pathogen of cattle. An attenuated live vaccine has recently been developed by this laboratory. However, an effective assay for the differentiation of infected from vaccinated animals (DIVA) is still lacking.
View Article and Find Full Text PDFThis study was undertaken to determine the genotypic distribution of Chinese M. bovis strains and their similarity to isolates from other countries. Two multilocus sequence typing (MLST) schemes (MLST-1 and MLST-2) and pulsed field gel electrophoresis (PFGE) were used to compare 44 Chinese strains and the M.
View Article and Find Full Text PDFis an important cause of bovine respiratory disease worldwide. To understand its virulence mechanisms, we sequenced three attenuated strains, P115, P150, and P180, which were passaged 115, 150, and 180 times, respectively, and exhibited progressively decreasing virulence. Comparative genomics was performed among the wild-type HB0801 (P1) strain and the P115, P150, and P180 strains, and one 14.
View Article and Find Full Text PDFIndirubin is a Chinese medicine extracted from indigo and known to be effective for treating chronic myelogenous leukemia, neoplasia, and inflammatory disease. This study evaluated the in vivo anti-inflammatory activity of indirubin in a lipopolysaccharide- (LPS-) induced mouse mastitis model. The indirubin mechanism and targets were evaluated in vitro in mouse mammary epithelial cells.
View Article and Find Full Text PDFMycoplasma bovis causes considerable economic losses in the cattle industry worldwide. In mycoplasmal infections, adhesion to the host cell is of the utmost importance. In this study, the amino acid sequence of NOX was predicted to have enzymatic domains.
View Article and Find Full Text PDFA lack of knowledge regarding the antigenic properties of Mycoplasma bovis proteins prevents the effective control of bovine infections using immunological approaches. In this study, we detected and characterized a specific and sensitive M. bovis diagnostic biomarker.
View Article and Find Full Text PDFTo determine the nationwide status of persistent BVDV infection in different bovine species in China and compare different test methods, a total of 1379 serum samples from clinical healthy dairy cattle, beef cattle, yaks (Bos grunniens), and water buffalo (Bubalus bubalis) were collected in eight provinces of China from 2010 to 2013. The samples were analyzed using commercial antibody (Ab) and antigen (Ag) detection kits, and RT-PCR based on the 5'-UTR and Npro gene sequencing. Results showed that the overall positive rates for BVDV Ab, Ag and RT-PCR detection were 58.
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