技术资料

Genome editing using CRISPR-Cas systems is a promising avenue for the treatment of genetic diseases. However,cellular and humoral immunogenicity of genome editing tools,which originate from bacteria,complicates their clinical use. Here we report reduced immunogenicity (Red)(i)-variants of two clinically relevant nucleases,SaCas9 and AsCas12a. Through MHC-associated peptide proteomics (MAPPs) analysis,we identify putative immunogenic epitopes on each nuclease. Using computational modeling,we rationally design these proteins to evade the immune response. SaCas9 and AsCas12a Redi variants are substantially less recognized by adaptive immune components,including reduced binding affinity to MHC molecules and attenuated generation of cytotoxic T cell responses,yet maintain wild-type levels of activity and specificity. In vivo editing of PCSK9 with SaCas9.Redi.1 is comparable in efficiency to wild-type SaCas9,but significantly reduces undesired immune responses. This demonstrates the utility of this approach in engineering proteins to evade immune detection. Subject terms: Protein design,Immunogenetics,CRISPR-Cas9 genome editing View Publication

Prime Editing can rewrite genes in living cells by allowing point mutations,deletions,or insertion of small DNA sequences with high precision. However,its safe and efficient delivery into human stem cells remains a technical challenge. In this report,we engineer Nanoscribes,virus-like particles that encapsidate ribonucleoprotein complexes of the Prime Editing system and allow their delivery into recipient cells. We identify key features that unlock the potential of Nanoscribes,including the use of multiple fusogens,the improvement of pegRNAs structures,their encoding by a Pol II system and the optimization of Prime-Editors. Nanoscribes edit HEK293T with an efficiency of 68% at the HEK3 locus with increased fidelity over DNA-transfection and support pegRNA-multiplexing. Importantly,Nanoscribes permit editing of myoblasts,hiPSCs and hiPSCs-derived hematopoietic stem cells with an editing efficiency up to 25%. Nanoscribes is an asset for development of next generation genome editing approaches using VLPs. Subject terms: CRISPR-Cas9 genome editing,Genetic vectors,Nanoparticles View Publication

Human norovirus (HuNoV) is a major cause of enteric infectious gastroenteritis and is classified into several genotypes based on its capsid protein amino acid sequence and nucleotide sequence of the polymerase gene. Among these,GII.4 is the major genotype worldwide. Epidemiological studies have highlighted the prevalence of GII.2. Although recent advances using human tissue– and induced pluripotent stem cell (iPSC)–derived intestinal epithelial cells (IECs) have enabled in vitro replication of multiple HuNoV genotypes,GII.2 HuNoV could replicate only in tissue-derived IECs and not in iPSC-derived IECs. We investigated the factors influencing GII.2 HuNoV replication in IECs,focusing on histo-blood group antigens. We also assessed the immunogenicity of GII.2 virus-like particles (VLPs) and their ability to induce neutralizing antibodies. Antibody cross-reactivity was tested to determine whether GII.2 VLPs could neutralize other HuNoV genotypes,including GII.4,GII.3,GII.6,and GII.17. Our findings indicated that GII.2 HuNoV replication in vitro requires the presence of both H and B antigens. Moreover,GII.2 VLPs generated neutralizing antibodies effective against both GII.2 and GII.4 but not against GII.3,GII.6,or GII.17. Comparatively,GII.2 and GII.17 VLPs induced broader neutralizing responses than GII.4 VLPs. The findings of this study suggests that GII.2 and GII.17 VLPs may be advantageous as HuNoV vaccine candidates because they elicit neutralizing antibodies against the predominant GII.4 genotype,which could be particularly beneficial for infants without prior HuNoV exposure. These insights will contribute to the development of effective HuNoV vaccines. View Publication

Polo-like kinase 1 (PLK1),a key regulator of the G2/M phase in mitosis,is frequently overexpressed in numerous tumors. Although PLK1 inhibitors have emerged as promising therapeutic agents for cancer,their use has been linked to significant anemia in a subset of patients,yet the underlying mechanisms remain poorly understood. In this study,we utilized an in vitro human umbilical cord blood-derived CD34 + cell-based erythroid differentiation system,alongside a murine model,to investigate the impact of PLK1 inhibitors on erythropoiesis. Our results indicate that PLK1 inhibitors,specifically GSK461364 and BI6727,significantly suppress the proliferation of erythroid cells,resulting in G2/M phase cell cycle arrest,increased apoptosis in erythroid cells,and the formation of abnormally nucleated late-stage erythroblasts. In vivo,administration of PLK1 inhibitors in mice induced severe anemia,as evidenced by a marked reduction in red blood cells and hemoglobin levels. More specifically,PLK1 inhibition impaired the differentiation and erythroid commitment of hematopoietic stem cells in the bone marrow,resulting in abnormal accumulation of BFU-E cells and reduced proliferation and differentiation of CFU-E,and a decrease in the number of terminal erythrocytes. Mechanistically,PLK1 inhibitors primarily induce apoptosis in erythroid cells by reducing Mitochondrial membrane potential and arresting the cell cycle at the G2/M phase. Overall,our findings underscore the critical role of PLK1 in erythropoiesis and shed light on the mechanisms underlying PLK1 inhibitor-induced anemia,providing essential guidance for developing strategies to prevent and manage anemia in clinical applications of PLK1-targeted therapies. View Publication

Previous studies have indicated that the presence of cancer stem cells may be a contributing factor to the development of metastasis in colorectal cancer patients. Cancer stem cells represent a small subpopulation within the tumor mass that exhibits heightened resistance to treatment and possesses the capacity for self-replication,epithelial–mesenchymal transition,and the generation of new tumors. The tumor microenvironment secretes and releases several molecules that facilitate the self-renewal of cancer stem cells and provide support for colorectal cancer progression. microRNAs are involved in direct cell-to-cell signaling and paracrine signaling between tumor cells and other tumor microenvironment components. They could act as tumor suppressors or oncomiRs,and their deregulation is involved in colorectal cancer progression and cancer stem cell formation. In our previous studies,we demonstrated the oncosuppressive function of miR-486-5p in colorectal cancer; these findings prompted us to conduct a more detailed investigation into its role in cancer stem cell phenotypes. Background: Colorectal cancer (CRC) is the third diagnosed cancer worldwide. Forty-four percent of metastatic colorectal cancer patients were diagnosed at an early stage. Despite curative resection,approximately 40% of patients will develop metastases within a few years. Previous studies indicate the presence of cancer stem cells (CSCs) and their contribution to CRC progression and metastasis. miRNAs deregulation plays a role in CSCs formation and in tumor development. In light of previous studies,we investigated the role of miR-486-5p to understand its role in CSC better. Methods: The expression of miR-486-5p was assessed in adherent cells and spheres generated from two CRC cell lines to observe the difference in expression in CSC-enriched spheroids. Afterward,we overexpressed and underexpressed this miRNA in adherent and sphere cultures through the transfection of a miR-486-5p mimic and a mimic inhibitor. Results: The results demonstrated that miR-486-5p exhibited a notable downregulation in CSC models,and its overexpression led to a significant decrease in colony size. Conclusions: In this study,we confirmed that miR-486-5p plays an oncosuppressive role in CRC,thereby advancing our understanding of the role of this microRNA in the CSC phenotype. View Publication

Cancer stem cells (CSCs) play a key role in non-small cell lung cancer (NSCLC) chemoresistance and metastasis. In this study,we used two NSCLC cell lines to investigate the regulating effect of hypoxia in the induction and maintenance of CSC traits. Our study demonstrated hypoxia-induced stemness and chemoresistance at levels comparable to those in typical CSC sphere culture. Activation of the NF-κB pathway (by transfection of NF-κB-p65) plays a key role in NSCLC CSCs and chemoresistance. Disulfiram (DS),an anti-alcoholism drug,showed a strong in vitro anti-CSC effect. It blocked cancer cell sphere reformation and clonogenicity,synergistically enhanced the cytotoxicity of four anti-NSCLC drugs (doxorubicin,gemcitabine,oxaliplatin and paclitaxel) and reversed hypoxia-induced resistance. The effect of DS on CSCs is copper-dependent. A very short half-life in the bloodstream is the major limitation for the translation of DS into a cancer treatment. Our team previously developed a poly lactic-co-glycolic acid (PLGA) nanoparticle encapsulated DS (DS-PLGA) with a long half-life in the bloodstream. Intra venous injection of DS-PLGA in combination with the oral application of copper gluconate has strong anticancer efficacy in a metastatic NSCLC mouse model. Further study may be able to translate DS-PLGA into cancer applications. View Publication

Introduction: Pathogenic variants in the OFD1 gene are linked to a spectrum of syndromes that exhibit partial clinical overlap. Hemizygous loss-of-function variants are considered lethal in males,while heterozygous loss-of-function variants generally result in oro-facial-digital syndrome type 1. A reported phenotype,Simpson–Golabi–Behmel syndrome type 2,was published once but remains controversial,with many specialists questioning its validity and arguing about its continued listing in the OMIM database. Methods: To investigate the genetic and phenotypic characteristics of the patients,we performed clinical exome sequencing,family-based genetic analysis,X-inactivation studies,electron microscopy,and detailed clinical assessments. Results: Three patients from unrelated families carrying loss-of-function variants in the OFD1 gene were identified,emphasizing the diverse phenotypic spectrum of OFD1 -associated disorders. The first patient,a female with a heterozygous frameshift variant p.(Gln398LeufsTer2),was diagnosed with oro-facial-digital syndrome type 1. The second patient,a male with a heterozygous nonsense variant p.(Gln892Ter),presented with features resembling Simpson–Golabi–Behmel syndrome type 2,as previously reported under this diagnosis. The third patient,a male with another heterozygous nonsense variant p.(Glu879Ter),exhibited isolated primary ciliary dyskinesia without any syndromic features. Conclusions: This study contributes to the growing body of evidence on the expanding phenotypic spectrum of OFD1 -associated disorders. It underscores the need for further investigation into the molecular mechanisms underlying the diverse presentations and the necessity of re-evaluating diagnostic classifications for conditions such as SGBS2 in the context of variants in the OFD1 gene. View Publication

Borrelia (or Borreliella ) burgdorferi,the causative agent of Lyme disease,is a motile and invasive zoonotic pathogen adept at navigating between its arthropod vector and mammalian host. While motility and chemotaxis are well known to be essential for its enzootic cycle,the role of each methyl-accepting chemotaxis proteins (MCPs) in the infectious cycle of B . burgdorferi remains unclear. In this study,we show that mcp5,a gene encoding one of the most abundant MCPs in B . burgdorferi,is differentially expressed in response to environmental signals and at distinct stages of the pathogen’s enzootic cycle. Notably,mcp5 expression is regulated by the Hk1-Rrp1 and Rrp2-RpoN-RpoS pathways,two key regulatory pathways that are critical for the spirochete’s colonization of the tick vector and mammalian host,respectively. Infection experiments with an mcp5 mutant revealed that spirochetes lacking MCP5 were unable to establish infections in either C3H/HeN mice or Severe Combined Immunodeficiency (SCID) mice,which are deficient in adaptive immunity,underscoring MCP5’s critical role in mammalian infection. However,the mcp5 mutant was able to establish infection and disseminate in NOD SCID Gamma (NSG) mice,which are deficient in both adaptive and most innate immune responses,suggesting that MCP5 plays an important role in evading host innate immunity. Moreover,NK cell depletion in C3H and SCID mice restored the infectivity of the mcp5 mutant,further highlighting MCP5’s role in evading NK cell-associated immunity. Co-culture assays with NK cells and macrophages revealed that the mcp5 mutant enhanced interferon-gamma production by NK cells. In the tick vector,the mcp5 mutants survived feeding but failed to transmit to mice. These findings reveal that MCP5,regulated by both the Rrp1 and Rrp2 pathways,is critical for establishing infection in mammalian hosts by evading NK cell-mediated host innate immunity and is important for the transmission of spirochetes from ticks to mammalian hosts. This work provides a foundation for further elucidation of chemotactic signals sensed by MCP5 that facilitate B . burgdorferi in evading host defenses. View Publication

Many respiratory viruses attack the airway epithelium and cause a wide spectrum of diseases for which we have limited therapies. To date,a few primary human stem cell-based models of the proximal airway have been reported for drug discovery but scaling them up to a higher throughput platform remains a significant challenge. As a result,most of the drug screening assays for respiratory viruses are performed on commercial cell line-based 2D cultures that provide limited translational ability. We optimized a primary human stem cell-based mucociliary airway epithelium model of SARS-CoV-2 infection,in 96-well air–liquid-interface (ALI) format,which is amenable to moderate throughput drug screening. We tested the model against SARS-CoV-2 parental strain (Wuhan) and variants Beta,Delta,and Omicron. We applied this model to screen 2100 compounds from targeted drug libraries using a high throughput-high content image-based quantification method. The model recapitulated the heterogeneity of infection among patients with SARS-CoV-2 parental strain and variants. While there were heterogeneous responses across variants for host factor targeting compounds,the two direct-acting antivirals we tested,Remdesivir and Paxlovid,showed consistent efficacy in reducing infection across all variants and donors. Using the model,we characterized a new antiviral drug effective against both the parental strain and the Omicron variant. This study demonstrates that the 96-well ALI model of primary human mucociliary epithelium can recapitulate the heterogeneity of infection among different donors and SARS-CoV-2 variants and can be used for moderate throughput screening. Compounds that target host factors showed variability among patients in response to SARS-CoV-2,while direct-acting antivirals were effective against SARS-CoV-2 despite the heterogeneity of patients tested. View Publication

Pseudomonas aeruginosa is a Gram-negative bacterium that is notorious for airway infections in cystic fibrosis (CF) subjects. Bacterial quorum sensing (QS) coordinates virulence factor expression and biofilm formation at population level. Better understanding of QS in the bacterium-host interaction is required. Here,we set up a new P. aeruginosa infection model,using 2D upper airway nasal organoids that were derived from 3D organoids. Using dual RNA-sequencing,we dissected the interaction between organoid epithelial cells and WT or QS-mutant P. aeruginosa strains. Since only a single healthy individual and a single CF subject were used as donors for the organoids,conclusions about CF-specific effects could not be deduced. However,P. aeruginosa induced epithelial inflammation,whereas QS signaling did not affect the epithelial airway cells. Conversely,the epithelium influenced infection-related processes of P. aeruginosa,including QS-mediated regulation. Comparison of our model with samples from the airways of CF subjects indicated that our model recapitulates important aspects of infection in vivo. Hence,the 2D airway organoid infection model is relevant and may help to reduce the future burden of P. aeruginosa infections in CF. The online version contains supplementary material available at 10.1038/s41598-024-82500-w. View Publication