Refining chimeric antigen receptors via barcoded protein domain combination pooled screening.

Chimeric antigen receptor (CAR)-T cells represent a promising frontier in cancer immunotherapy. However, the current process for developing new CAR constructs is time consuming and inefficient. To address this challenge and expedite the evaluation and comparison of full-length CAR designs, we have devised a novel cloning strategy. This strategy involves the sequential assembly of individual CAR domains using blunt ligation, with each domain being assigned a unique DNA barcode. Applying this method, we successfully generated 360 CAR constructs that specifically target clinically validated tumor antigens CD19 and GD2. By quantifying changes in barcode frequencies through next-generation sequencing, we characterize CARs that best mediate proliferation and expansion of transduced T cells. The screening revealed a crucial role for the hinge domain in CAR functionality, with CD8a and IgG4 hinges having opposite effects in the surface expression, cytokine production, and antitumor activity in CD19- versus GD2-based CARs. Importantly, we discovered two novel CD19-CAR architectures containing the IgG4 hinge domain that mediate superior in vivo antitumor activity compared with the construct used in Kymriah, a U.S. Food and Drug Administration (FDA)-approved therapy. This novel screening approach represents a major advance in CAR engineering, enabling accelerated development of cell-based cancer immunotherapies.

Self-assembly Induced Enhanced Electrochemiluminescence of Copper Nanoclusters Using DNA Nanoribbon Templates.

Copper nanoclusters (CuNCs) are attractive electrochemiluminescence (ECL) emitters as Cu is comparatively inexpensive, nontoxic, and highly abundant. However, their ECL yield is relatively low. Herein, we report that orderly self-assembly of CuNCs using DNA nanoribbon as the template (DNR/CuNCs) conferred the CuNCs with improved ECL properties compared with individual CuNCs in both annihilation and co-reactant processes. The DNR/CuNCs resulted in a high ECL yield of 46.8 % in K2 S2 O8 , which was ≈68 times higher than that of individual CuNCs. This strategy was successfully extended to other ECL emitters, such as gold nanoclusters and the Ru(bpy)3 2+ /TPrA system. Furthermore, as an application of DNR/CuNCs, a DNR/CuNC-based ECL biosensor with higher sensitivity was constructed for dopamine determination (two orders of magnitude lower than that previously reported), showing that DNR/CuNCs have a potential for application in ECL bioanalysis as a new type of superior luminophore candidate.

Endoscopic transcecal appendectomy: a new endotherapy for appendiceal orifice lesions.

BACKGROUND: Endoscopic transcecal appendectomy (ETA) has been reported as a minimally invasive alternative procedure for lesions involving the appendiceal orifice. The aim of this case series study was to evaluate the feasibility, safety, and effectiveness of ETA for lesions at the appendiceal orifice. METHODS: This retrospective study included consecutive patients with appendiceal orifice lesions who underwent ETA between December 2018 and March 2021. The primary outcome was technical success. The secondary outcomes included postoperative adverse events, postoperative hospital stay, and recurrence. RESULTS: 13 patients with appendiceal orifice lesions underwent ETA during the study period. The median lesion size was 20 mm (range 8-50). Lesions morphologies were polypoid lesions (n = 5), laterally spreading tumors (n = 4), and submucosal lesions (n = 4). Technical success with complete resection was achieved in all 13 cases. There were no postoperative bleeding, perforation, or intra-abdominal abscess. The median length of hospital stay after ETA was 8 days (range 6-18). There was no tumor recurrence during a median follow-up of 17 months (range 1-28). CONCLUSIONS: ETA is feasible, safe, and effective for complete resection of appendiceal orifice lesions. Larger, multicenter, prospective studies are needed to further assess this technique.

Four-Component Reaction Access to Nitrile-Substituted All-Carbon Quaternary Centers.

A four-component reaction strategy for access to acyclic nitrile-substituted all-carbon quaternary centers is disclosed. In the presence of a DABCO-based ionic liquid catalyst, the reactions proceed smoothly with a wide range of substrates efficiently to deliver nitrile-substituted all-carbon quaternary centers under mild reaction conditions. This protocol is further demonstrated as an efficient method for the construction of contiguous all-carbon quaternary centers. All the reactions are easily operated in a green manner, producing water as the only byproduct. Some of the products show excellent activity against specific fungi.

Artificial intelligence for detecting superficial esophageal squamous cell carcinoma under multiple endoscopic imaging modalities: A multicenter study.

BACKGROUND AND AIM: Diagnosis of esophageal squamous cell carcinoma (ESCC) is complicated and requires substantial expertise and experience. This study aimed to develop an artificial intelligence (AI) system for detecting superficial ESCC under multiple endoscopic imaging modalities. METHODS: Endoscopic images were retrospectively collected from West China Hospital, Sichuan University as a training dataset and an independent internal validation dataset. Images from other four hospitals were used as an external validation dataset. The AI system was compared with 11 experienced endoscopists. Furthermore, videos were collected to assess the performance of the AI system. RESULTS: A total of 53 933 images from 2621 patients and 142 videos from 19 patients were used to develop and validate the AI system. In the internal and external validation datasets, the performance of the AI system under all or different endoscopic imaging modalities was satisfactory, with sensitivity of 92.5-99.7%, specificity of 78.5-89.0%, and area under the receiver operating characteristic curves of 0.906-0.989. The AI system achieved comparable performance with experienced endoscopists. Regarding superficial ESCC confined to the epithelium, the AI system was more sensitive than experienced endoscopists on white-light imaging (90.8% vs 82.5%, P = 0.022). Moreover, the AI system exhibited good performance in videos, with sensitivity of 89.5-100% and specificity of 73.7-89.5%. CONCLUSIONS: We developed an AI system that showed comparable performance with experienced endoscopists in detecting superficial ESCC under multiple endoscopic imaging modalities and might provide valuable support for inexperienced endoscopists, despite requiring further evaluation.

Remote Photothermal Control of DNA Origami Assembly in Cellular Environments.

In situ synthesis of DNA origami structures in living systems is highly desirable due to its potential in biological applications, which nevertheless is hampered by the requirement of thermal activation procedures. Here, we report a photothermal DNA origami assembly method in near-physiological environments. We find that the use of copper sulfide nanoparticles (CuS NPs) can mediate efficient near-infrared (NIR) photothermal conversion to remotely control the solution temperature. Under a 4 min NIR illumination and subsequent natural cooling, rapid and high-yield (>80%) assembly of various types of DNA origami nanostructures is achieved as revealed by atomic force microscopy and single-molecule fluorescence resonance energy transfer analysis. We further demonstrate the in situ assembly of DNA origami with high location precision in cell lysates and in cell culture environments.

Directing Multivalent Aptamer-Receptor Binding on the Cell Surface with Programmable Atom-Like Nanoparticles.

Multivalent interactions of biomolecules play pivotal roles in physiological and pathological settings. Whereas the directionality of the interactions is crucial, the state-of-the-art synthetic multivalent ligand-receptor systems generally lack programmable approaches for orthogonal directionality. Here, we report the design of programmable atom-like nanoparticles (aptPANs) to direct multivalent aptamer-receptor binding on the cell interface. The positions of the aptamer motifs can be prescribed on tetrahedral DNA frameworks to realize atom-like orthogonal valence and direction, enabling the construction of multivalent molecules with fixed aptamer copy numbers but different directionality. These directional-yet-flexible aptPAN molecules exhibit the adaptability to the receptor distribution on cell surfaces. We demonstrate the high-affinity tumor cell binding with a linear aptPAN oligomer (≈13-fold improved compared to free aptamers), which leads to ≈50 % suppression of cell growth.

Detection of multiple lesions of gastrointestinal tract for endoscopy using artificial intelligence model: a pilot study.

BACKGROUND: This study was aimed to develop a computer-aided diagnosis (CAD) system with deep-learning technique and to validate its efficiency on detecting the four categories of lesions such as polyps, advanced cancer, erosion/ulcer and varices at endoscopy. METHODS: A deep convolutional neural network (CNN) that consists of more than 50 layers were trained with a big dataset containing 327,121 white light images (WLI) of endoscopy from 117,005 cases collected from 2012 to 2017. Two CAD models were developed using images with or without annotation of the training dataset. The efficiency of the CAD system detecting the four categories of lesions was validated by another dataset containing consecutive cases from 2018 to 2019. RESULTS: A total of 1734 cases with 33,959 images were included in the validation datasets which containing lesions of polyps 1265, advanced cancer 500, erosion/ulcer 486, and varices 248. The CAD system developed in this study may detect polyps, advanced cancer, erosion/ulcer and varices as abnormality with the sensitivity of 88.3% and specificity of 90.3%, respectively, in 0.05 s. The training datasets with annotation may enhance either sensitivity or specificity about 20%, p = 0.000. The sensitivities and specificities for polyps, advanced cancer, erosion/ulcer and varices reached about 90%, respectively. The detect efficiency for the four categories of lesions reached to 89.7%. CONCLUSION: The CAD model for detection of multiple lesions in gastrointestinal lumen would be potentially developed into a double check along with real-time assessment and interpretation of the findings encountered by the endoscopists and may be a benefit to reduce the events of missing lesions.

Poly-Adenine-Based Spherical Nucleic Acids for Efficient Live-Cell MicroRNA Capture.

Direct delivery of exogenous non-coding nucleic acids into living cells has attracted intense interest in biological applications. However, the cell entry efficiency and target capture ability remain to be improved. Herein, we report a method for compartmenting the nucleic acids on the surface of poly-adenine-based spherical nucleic acids (polyA-SNAs) for efficient capture of oncogenic microRNAs (miRNAs) in living cells. We find that polyA-SNAs exhibit high cell entry efficiency, which is insensitive to the configuration of the anti-miRNA sequences. By programming the length of polyAs, we precisely engineered the spatial configuration of the anti-miRNA sequences in polyA-SNAs. Compartmentalized polyA-SNAs bind to miRNAs with improved capture ability as compared to densely compacted SNAs. We further demonstrate that polyA-SNAs serve as high-efficacy miRNA sponges for capturing oncogenic miRNAs both in living cells and in mice. The efficient inhibition of miRNAs results in significant suppression of tumor growth.

Programming Cell-Cell Communications with Engineered Cell Origami Clusters.

Cells existing in the form of clusters often exhibit distinct physiological functions from their monodispersed forms, which have a close association with tissue and organ development, immunoresponses, and cancer metastasis. Nevertheless, the ability to construct artificial cell clusters as in vitro models for probing and manipulating intercellular communications remains limited. Here we design DNA origami nanostructure (DON)-based biomimetic membrane channels to organize cell origami clusters (COCs) with controlled geometric configuration and cell-cell communications. We demonstrate that programmable patterning of homotypic and heterotypic COCs with different configurations can result in three distinct types of intercellular communications: gap junctions, tunneling nanotubes, and immune/tumor cell interactions. In particular, the organization of T cells and cancer cells with a prescribed ratio and geometry can program in vitro immunoresponses, providing a new route to understanding and engineering cancer immunotherapy.

Programming Switchable Transcription of Topologically Constrained DNA.

Genomic DNA is compacted via chromatin condensation in mammalian cells, and transcription of such topologically constrained DNA to messenger RNA is under strict spatiotemporal regulation. Nevertheless, control of DNA topology has been poorly explored in in vitro transcription and gene transfection. Here we report the construction of topologically ordered (TO-) prokaryotic genes composed of linear DNA templates appended with a T7 promoter sequence with the use of DNA self-assembly. We find that TO-DNA maintains the transcription activity whereas the activity is critically dependent on the configuration of the T7 promoter in a folded DNA nanostructure. By prescribing the position and the intactness of the T7 promoter, we can dynamically activate or repress transcription in response to specific DNA key strands in a Boolean logic manner. Bioorthogonal switchable transcription is realized with the insertion of multiple genes in a TO-DNA. Further, implementing TO-DNA in living bacteria leads to switchable transcription of fluorescent RNA aptamers for light-up cell imaging. Hence, the design of TO-DNAs provides a means for shape-dependent gene delivery, enriching the toolbox of genetic engineering and synthetic biology.

DNA Origami-Enabled Engineering of Ligand-Drug Conjugates for Targeted Drug Delivery.

Effective drug delivery systems that can systematically and selectively transport payloads to disease cells remain a challenge. Here, a targeting ligand-modified DNA origami nanostructure (DON) as an antibody-drug conjugate (ADC)-like carrier for targeted prostate cancer therapy is reported. Specifically, DON of six helical bundles is modified with a ligand 2-[3-(1,3-dicarboxy propyl)-ureido] pentanedioic acid (DUPA) against prostate-specific membrane antigen (PSMA), to serve as the antibody for drug conjugation in ADC. Doxorubicin (Dox) is then loaded to DON through intercalation to dsDNA. This platform features in spatially controllable organization of targeting ligands and high drug loading capacity. With this nanocomposite, selective delivery of Dox to the PSMA+ cancer cell line LNCaP is readily achieved. The consequent therapeutic efficacy is critically dependent on the numbers of targeting ligand assembled on DON. This target-specific and biocompatible drug delivery platform with high maximum tolerated doses shows immense potential for developing novel nanomedicine.

Real-time automated diagnosis of precancerous lesions and early esophageal squamous cell carcinoma using a deep learning model (with videos).

BACKGROUND AND AIMS: We developed a system for computer-assisted diagnosis (CAD) for real-time automated diagnosis of precancerous lesions and early esophageal squamous cell carcinomas (ESCCs) to assist the diagnosis of esophageal cancer. METHODS: A total of 6473 narrow-band imaging (NBI) images, including precancerous lesions, early ESCCs, and noncancerous lesions, were used to train the CAD system. We validated the CAD system using both endoscopic images and video datasets. The receiver operating characteristic curve of the CAD system was generated based on image datasets. An artificial intelligence probability heat map was generated for each input of endoscopic images. The yellow color indicated high possibility of cancerous lesion, and the blue color indicated noncancerous lesions on the probability heat map. When the CAD system detected any precancerous lesion or early ESCCs, the lesion of interest was masked with color. RESULTS: The image datasets contained 1480 malignant NBI images from 59 consecutive cancerous cases (sensitivity, 98.04%) and 5191 noncancerous NBI images from 2004 cases (specificity, 95.03%). The area under curve was 0.989. The video datasets of precancerous lesions or early ESCCs included 27 nonmagnifying videos (per-frame sensitivity 60.8%, per-lesion sensitivity, 100%) and 20 magnifying videos (per-frame sensitivity 96.1%, per-lesion sensitivity, 100%). Unaltered full-range normal esophagus videos included 33 videos (per-frame specificity 99.9%, per-case specificity, 90.9%). CONCLUSIONS: A deep learning model demonstrated high sensitivity and specificity for both endoscopic images and video datasets. The real-time CAD system has a promising potential in the near future to assist endoscopists in diagnosing precancerous lesions and ESCCs.

Endoscopic submucosal dissection with additional radiotherapy in the treatment of T1a esophageal squamous cell cancer: randomized controlled Trial.

BACKGROUND: Endoscopic submucosal dissection (ESD) is effective for treating T1a early esophageal squamous cell carcinoma (ESCC). However, occasional recurrences are inevitable. This trial was designed to clarify the efficacy of combining ESD with additional radiotherapy in the treatment of T1a ESCC. METHODS: Between January 2015 and September 2018, patients with early ESCC (T1aN0M0) following ESD were randomly assigned (1:1) to the radiotherapy group or non-radiotherapy group. Patients in the radiotherapy group received a median radiation dose of 59.4 Gy within 2 months after ESD. In the non-radiotherapy group, patients underwent regular follow-up only. Recurrence-free survival, cancer-specific survival, overall survival, and complications were evaluated. RESULTS: 70 patients completed the per-protocol treatment. Three patients in the non-radiotherapy group experienced intraluminal mucosal recurrence compared with none in the radiotherapy group. No local lymph node or distant metastases occurred in either group. The 3-year cumulative recurrence-free survival was 100 % in the radiotherapy group and 85.3 % in the non-radiotherapy group (P = 0.04; hazard ratio 0.08, 95 % confidence interval [CI] 0.01 - 0.86). However, there was no significant difference in RFS between the treatments within the T1a invasion subgroups (P > 0.05). No patient died in either group. Mucosal defects of more than three-quarters of the esophageal circumference were positively correlated with stenosis (P < 0.01; odds ratio 23.26, 95 %CI 4.04 - 133.86). No severe radiation toxicities were recorded. CONCLUSIONS: Radiotherapy after ESD might be a safe and effective optional therapeutic strategy to prevent recurrence of T1a ESCC.

IL-21 Selectively Protects CD62L+ NKT Cells and Enhances Their Effector Functions for Adoptive Immunotherapy.

T cells expressing CD19-specific chimeric Ag receptors (CARs) produce high remission rates in B cell lymphoma, but frequent disease recurrence and challenges in generating sufficient numbers of autologous CAR T cells necessitate the development of alternative therapeutic effectors. Vα24-invariant NKTs have intrinsic antitumor properties and are not alloreactive, allowing for off-the-shelf use of CAR-NKTs from healthy donors. We recently reported that CD62L+ NKTs persist longer and have more potent antilymphoma activity than CD62L- cells. However, the conditions governing preservation of CD62L+ cells during NKT cell expansion remain largely unknown. In this study, we demonstrate that IL-21 preserves this crucial central memory-like NKT subset and enhances its antitumor effector functionality. We found that following antigenic stimulation with α-galactosylceramide, CD62L+ NKTs both expressed IL-21R and secreted IL-21, each at significantly higher levels than CD62L- cells. Although IL-21 alone failed to expand stimulated NKTs, combined IL-2/IL-21 treatment produced more NKTs and increased the frequency of CD62L+ cells versus IL-2 alone. Gene expression analysis comparing CD62L+ and CD62L- cells treated with IL-2 alone or IL-2/IL-21 revealed that the latter condition downregulated the proapoptotic protein BIM selectively in CD62L+ NKTs, protecting them from activation-induced cell death. Moreover, IL-2/IL-21-expanded NKTs upregulated granzyme B expression and produced more TH1 cytokines, leading to enhanced in vitro cytotoxicity of nontransduced and anti-CD19-CAR-transduced NKTs against CD1d+ and CD19+ lymphoma cells, respectively. Further, IL-2/IL-21-expanded CAR-NKTs dramatically increased the survival of lymphoma-bearing NSG mice compared with IL-2-expanded CAR-NKTs. These findings have immediate translational implications for the development of NKT cell-based immunotherapies targeting lymphoma and other malignancies.

Risk factors for distal migration of biliary plastic stents and related duodenal injury.

BACKGROUND: The risk factors of duodenal injury from distal migrated biliary plastic stents remain uncertain. The aim of this study was to determine the risk factors of distal migration and its related duodenal injury in patients who underwent placement of a single biliary plastic stent for biliary strictures. METHODS: We retrospectively reviewed all patients with biliary strictures who underwent endoscopic placement of a single biliary plastic stent from January 2006 to October 2017. RESULTS: Two hundred forty-eight patients with 402 endoscopic retrograde cholangiopancreatography procedures were included. The incidence of distal migration was 6.2%. The frequency of duodenal injury was 2.2% in all cases and 36% in cases with distal migration. Benign biliary strictures (BBS), length of the stent above the proximal end of the stricture (> 2 cm), and duration of stent retention (< 3 months) were independently associated with distal migration (p = 0.018, p = 0.009, and p = 0.016, respectively). Duodenal injury occurred more commonly in cases with larger angle (≥ 30°) between the distal end of the stent and the centerline of the patient's body (p = 0.018) or in cases with stent retention < 3 months (p = 0.031). CONCLUSIONS: The risk factors of distal migration are BBS and the length of the stent above the proximal end of the stricture. The risk factor of duodenal injury due to distal migration is large angle (≥ 30°) between the distal end of the stent and the centerline of the patient's body. Distal migration and related duodenal injury are more likely to present during the early period after biliary stenting.

DNA Nanoribbon-Templated Self-Assembly of Ultrasmall Fluorescent Copper Nanoclusters with Enhanced Luminescence.

Fluorescent copper nanoclusters (CuNCs) have been widely used in chemical sensors, biological imaging, and light-emitting devices. However, individual fluorescent CuNCs have limitations in their capabilities arising from poor photostability and weak emission intensities. As one kind of aggregation-induced emission luminogen (AIEgen), the formation of aggregates with high compactness and good order can efficiently improve the emission intensity, stability, and tunability of CuNCs. Here, DNA nanoribbons, containing multiple specific binding sites, serve as a template for in situ synthesis and assembly of ultrasmall CuNCs (0.6 nm). These CuNC self-assemblies exhibit enhanced luminescence and excellent fluorescence stability because of tight and ordered arrangement through DNA nanoribbons templating. Furthermore, the stable and bright CuNC assemblies are demonstrated in the high-sensitivity detection and intracellular fluorescence imaging of biothiols.

Detection of Performance of Hybrid Rice Pot-Tray Sowing Utilizing Machine Vision and Machine Learning Approach.

Monitoring the performance of hybrid rice seeding is very important for the seedling production line to adjust the sowing amount of the seeding device. The objective of this paper was to develop a system for the real-time online monitoring of the performance of hybrid rice seeding based on embedded machine vision and machine learning technology. The embedded detection system captured images of pot trays that passed under the illuminant cabinet installed in the seedling production line. This paper proposed an algorithm for fixed threshold segmentation by analyzing the images with the exploratory analysis method. With the algorithm, the grid image and seed image were extracted from the pot tray image. The paper also proposed a method for obtaining pixel coordinates of gridlines from the grid image. Binary images of seeds were divided into small pieces, according to the pixel coordinates of gridlines. Each piece corresponded to a cell on the pot tray. By scanning the contours in each piece of the image to check whether there were seeds in the cell, the number of empty cells was counted and then used to calculate the missing rate of hybrid rice seeding. The seed number sowed in pot trays was monitored while using the machine learning approach. The experimental results demonstrated that it would consume 4.863 s for the device to process an image, which allowed for the detection of the missing rate and seed number in real-time at the rate of 500 trays per hour (7.2 s per tray). The average accuracy of the detection of missing rates of a seedling production line was 94.67%. The average accuracy of the detection of seed numbers was 95.68%.