The efficacy of T-cell therapy is inhibited by various tumor-associated immunosuppressive ligands and soluble factors. Such inhibitory signals turn specific T-cell signaling pathways on or off, impeding the anticancer functions of T cells. Many studies have focused on PD-1 or CTLA-4 blockade to invigorate T-cell functions through CD28/B7 signaling, but obtaining robust clinical outcomes remains challenging. In this study, we use CRISPR/Cas9 to potentiate T-cell function by increasing CD3 signaling via knockout of diacylglycerol kinase (DGK), an enzyme that metabolizes diacylglycerol to phosphatidic acid. Knockout of DGK augmented the effector functions of CAR-T cells via increased TCR signaling. DGK knockout from CAR-T cells rendered them resistant to soluble immunosuppressive factors such as TGFβ and prostaglandin E2 and sustained effector functions under conditions of repeated tumor stimulation. Moreover, DGK knockout caused significant regression of U87MGvIII glioblastoma tumors through enhanced effector functions in a xenograft mouse model. Collectively, our study shows that knockout of DGK effectively enhances the effector functions of CAR-T cells, suggesting that CRISPR/Cas9-mediated knockout of DGK could be applicable as part of a multifaceted clinical strategy to treat solid cancers. This novel study demonstrates efficient ablation of diacylglycerol kinase in human CAR-T cells that leads to improved antitumor immunity and may have significant impact in human cancer immunotherapy. .

Defect engineering has brought about a unique level of control for Si-based semiconductors, leading to the optimization of various opto-electronic properties and devices. With regard to perovskite transition metal oxides, O vacancies have been a key ingredient in defect engineering, as they play a central role in determining the crystal field and consequent electronic structure, leading to important electronic and magnetic phase transitions. Therefore, experimental approaches toward understanding the role of defects in complex oxides have been largely limited to controlling O vacancies. In this study, we report on the selective formation of different types of elemental vacancies and their individual roles in determining the atomic and electronic structures of perovskite SrTiO3 (STO) homoepitaxial thin films fabricated by pulsed laser epitaxy. Structural and electronic transitions have been achieved via selective control of the Sr and O vacancy concentrations, respectively, indicating a decoupling between the two phase transitions. In particular, O vacancies were responsible for metal-insulator transitions, but did not influence the Sr vacancy induced cubic-to-tetragonal structural transition in epitaxial STO thin film. The independent control of multiple phase transitions in complex oxides by exploiting selective vacancy engineering opens up an unprecedented opportunity toward understanding and customizing complex oxide thin films.

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PurposeBacillus Calmette-Guérin (BCG) is known to suppress the asthmatic responses in a murine model of asthma and to induce dendritic cells (DCs) maturation. Mature DCs play a crucial role in the differentiation of regulatory T cells (Tregs), which are known to regulate allergic inflammatory responses. To investigate whether BCG regulates Tregs in a DCs-mediated manner, we analyzed in a murine model of asthma.MethodsBALB/c mice were injected intraperitoneally with BCG or intravenously with BCG-stimulated DCs and then sensitized and challenged with ovalbumin (OVA). Mice were analysed for bronchial hyperresponsiveness (BHR), the influx of inflammatory cells in the bronchoalveolar lavage (BAL) fluid, and histopathological changes in the lung. To identify the mechanisms, IgE, IgG1 and IgG2a in the serum were analysed and the CD25+ Tregs in the mice were depleted with anti-CD25 monoclonal antibody (mAb).ResultsBCG and the transfer of BCG-stimulated DCs both suppressed all aspects of the asthmatic responses, namely, BHR, the production of total IgE and OVA-specific IgE and IgGs, and pulmonary eosinophilic inflammation. Anti-CD25mAb treatment reversed these effects.ConclusionsBCG can attenuate the allergic inflammation in a mouse model of asthma by a Tregs-related mechanism that is mediated by DCs.