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Natural killer T cells (NKTs) are a promising platform for cancer immunotherapy, but few genes involved in regulation of NKT therapeutic activity have been identified. To find regulators of NKT functional fitness, we developed a CRISPR/Cas9-based mutagenesis screen that employs a guide RNA (gRNA) library targeting 1,118 immune-related genes. Unmodified NKTs and NKTs expressing a GD2-specific chimeric antigen receptor (GD2.CAR) were transduced with the gRNA library and exposed to CD1d+ leukemia or CD1d-GD2+ neuroblastoma cells, respectively, over six challenge cycles in vitro. Quantification of gRNA abundance revealed enrichment of PRDM1-specific gRNAs in both NKTs and GD2.CAR NKTs, a result that was validated through targeted PRDM1 knockout. Transcriptional, phenotypic, and functional analyses demonstrated that CAR NKTs with PRDM1 knockout underwent central memory-like differentiation and resisted exhaustion. However, these cells downregulated the cytotoxic mediator granzyme B and showed reduced in vitro cytotoxicity and only moderate in vivo antitumor activity in a xenogeneic neuroblastoma model. In contrast, shRNA-mediated PRDM1 knockdown preserved effector function while promoting central memory differentiation, resulting in GD2.CAR NKTs with potent in vivo antitumor activity. Thus, we have identified PRDM1 as a regulator of NKT memory differentiation and effector function that can be exploited to improve the efficacy of NKT-based cancer immunotherapies.

The ability of immune cells to expand numerically after infusion distinguishes adoptive immunotherapies from traditional drugs, providing unique therapeutic advantages as well as the potential for unmanageable toxicities. Here, we describe a case of lethal hyperleukocytosis in a patient with neuroblastoma treated on phase 1 clinical trial (NCT03294954) with autologous natural killer T cells (NKTs) expressing a GD2-specific chimeric antigen receptor and cytokine interleukin 15 (GD2-CAR.15). This patient was the first to be treated on dose level (DL) 5 and the first patient whose product was restimulated with K562-derived artificial antigen-presenting cells (aAPCs) instead of autologous peripheral blood mononuclear cells (PBMCs). 12 previously treated patients on DLs 1 through 4 did not experience significant toxicity. Our root-cause analysis revealed no genetic alterations of known clinical significance and excluded the possibility of clonal expansion due to insertional retroviral mutagenesis. We report that the use of aAPCs instead of PBMCs for CAR-NKT restimulation contributed to a hyperproliferative state associated with distinct gene expression that possibly led to explosive lymphocyte expansion and uncontrolled toxicity in the patient. These findings warrant the implementation of measures to control immune cell activation during manufacture of cell therapy products, especially those armed with transgenic cytokines., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Introduction: Rapid On-Site Evaluation of cytological samples obtained through fine needle aspiration for adequacy is a critical component of a cytology service; however, it imposes a significant time and cost burden for the practicing pathologist and the cytology service. Telecytology enables adequacy assessment by a pathologist remotely, greatly saving time. Telecytology also allows slide preparation and manipulation at the procedure site by an employee with less training requirements, liberating the cytotechnologist to screen cases and perform other laboratory duties - an important aspect to consider during times of cytotechnologist shortages. We propose a telecytology system with a simple setup of a microscope, microscope camera, laptop, and Microsoft Teams software., Materials and Methods: We designed a system consisting of a mobile cart, backup battery, microscope, digital camera, and a laptop computer with microscope imaging software and Microsoft Teams software for image transmission. Validation was performed by 4 pathologists making adequacy assessments on randomly selected previously signed out cases using the telecytology system., Results: Our validation of this system demonstrated a greater than 90% concurrence rate between the original adequacy call and the call made by pathologists using the telecytology system - a benchmark used by most, if not all, published validations of similar telecytology systems. In addition, the adequacy assessment concordance rate between select pathologists exceeded 90%., Conclusions: In summary, our telecytology system provides excellent adequacy services for the clinicians and patients we serve. The Microsoft Teams software is a great tool for transmission of video microscopy. This system will be used with the goal of saving time and increasing efficiency for the cytopathology department., (Copyright © 2024 American Society of Cytopathology. Published by Elsevier Inc. All rights reserved.)

The CRISPR/Cas9 system enables a versatile set of genomes editing and genetic-based disease modeling tools due to its high specificity, efficiency, and accessible design and implementation. In cancer, the CRISPR/Cas9 system has been used to characterize genes and explore different mechanisms implicated in tumorigenesis. Different experimental strategies have been proposed in recent years, showing dependency on various intrinsic factors such as cancer type, gene function, mutation type, and technical approaches such as cell line, Cas9 expression, and transfection options. However, the successful methodological approaches, genes, and other experimental factors have not been analyzed. We, therefore, initially considered more than 1,300 research articles related to CRISPR/Cas9 in cancer to finally examine more than 400 full-text research publications. We summarize findings regarding target genes, RNA guide designs, cloning, Cas9 delivery systems, cell enrichment, and experimental validations. This analysis provides valuable information and guidance for future cancer gene validation experiments., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Several genes are significantly mutated in breast cancer but only a small percentage of mutations are well-known to contribute to cancer development. FASN is involved in de novo lipogenesis and the regulation of ERα signaling. However, the effect of genetic mutations affecting FASN in breast cancer has not thoroughly studied. Therefore, we used the CRISPR/Cas9 system to edit the FASN locus in MCF-7 cells and evaluated its biological effect. We obtained four clones carrying mutations and frameshifts in the acyl-transferase domain of FASN. We found that clones had reduced proliferation, migration, viability, and showed alterations in cell cycle profiles. RNA-Seq analysis demonstrates that a lack of fully functional FASN may have a more significant role in proliferation-related genes than in lipid metabolism. We conclude that functional knockouts in FASN contributes to decrease the proliferation and migration of breast cancer cells contrary to point mutations in breast cancer patients., Competing Interests: Declaration of competing interests, (Copyright © 2020 Elsevier Inc. All rights reserved.)