Project description:Anti-CD19 chimeric antigen receptor (CD19-CAR)-engineered T cells are approved therapeutics for malignancies. The impact of the hinge domain (HD) and the transmembrane domain (TMD) between the extracellular antigen-targeting CARs and the intracellular signaling modalities of CARs has not been systemically studied. In this study, a series of 19-CARs differing only by their HD (CD8, CD28, or IgG4) and TMD (CD8 or CD28) was generated. CARs containing a CD28-TMD, but not a CD8-TMD, formed heterodimers with the endogenous CD28 in human T cells, as shown by co-immunoprecipitation and CAR-dependent proliferation of anti-CD28 stimulation. This dimerization was dependent on polar amino acids in the CD28-TMD and was more efficient with CARs containing CD28 or CD8 HD than IgG4-HD. The CD28-CAR heterodimers did not respond to CD80 and CD86 stimulation but had a significantly reduced CD28 cell-surface expression. These data unveiled a fundamental difference between CD28-TMD and CD8-TMD and indicated that CD28-TMD can modulate CAR T-cell activities by engaging endogenous partners.
Project description:BackgroundIn many situations, the therapeutic efficacy of CAR T cells is limited due to immune suppression and poor persistence. Immunostimulatory fusion protein (IFP) constructs have been advanced as a tool to convert suppressive signals into stimulation and thus promote the persistence of T cells, but no universal IFP design has been established so far. We now took advantage of a PD-1-CD28 IFP as a clinically relevant structure to define key determinants of IFP activity.MethodsWe compared different PD-1-CD28 IFP variants in a human leukemia model to assess the impact of distinctive design choices on CAR T cell performance in vitro and a xenograft mouse model.ResultsWe observed that IFP constructs that putatively exceed the extracellular length of PD-1 induce T-cell response without CAR target recognition, rendering them unsuitable for tumour-specific therapy. IFP variants with physiological PD-1 length ameliorated CAR T cell effector function and proliferation in response to PD-L1+ tumour cells in vitro and prolonged survival in vivo. Transmembrane or extracellular CD28 domains were found to be replaceable by corresponding PD-1 domains for in vivo efficacy.ConclusionPD-1-CD28 IFP constructs must mimic the physiological interaction of PD-1 with PD-L1 to retain selectivity and mediate CAR-conditional therapeutic activity.
Project description:BackgroundIn recent years, the incidence of thyroid nodules has increased significantly. There are various ways to treat thyroid nodules, and ablation therapy is one of the important ways to treat thyroid nodules. However, there are many complications and deficiencies in the current ablation treatment of thyroid nodules, especially the incomplete ablation of thyroid cancer nodules, which limits the further application of ablation technology. In this paper, we report two cases of incomplete ablation of thyroid nodules, one of which underwent surgical treatment due to anxiety after ablation, and the postoperative pathology confirmed that there was still residual papillary thyroid carcinoma, and the other patient underwent an operation after ablation, but visited our medical institution again due to cervical lymph node metastasis in a short period of time, and after radical cervical lymph node dissection, pathology confirmed multiple cervical lymph node metastasis. Radionuclide therapy was performed after surgery, and two patients are currently receiving endocrine suppression therapy, and their condition is stable with no signs of recurrence.ConclusionThe incomplete ablation of thyroid cancer nodules limits the development of ablation therapy, making ablation treatment a double-edged sword. Guidelines and expert consensus can guide their development, but they need to evolve with the times, and a multidisciplinary diagnostic team can help screen the most suitable patients. Only by using this technology more standardly, using the most appropriate technology, and treating the most suitable patients, can benefit more and more patients.
Project description:Guided by evolutionarily signaled vulnerabilities in the structure of SARS-CoV-2, we identify epitopes in free monomers of the spike protein that steer the generation of induced or administered antibodies geared at promoting destabilization of the virus quaternary structure, thereby hampering infectivity.
Project description:BackgroundThe assessment of calibration performance of risk prediction models based on regression or more flexible machine learning algorithms receives little attention.Main textHerein, we argue that this needs to change immediately because poorly calibrated algorithms can be misleading and potentially harmful for clinical decision-making. We summarize how to avoid poor calibration at algorithm development and how to assess calibration at algorithm validation, emphasizing balance between model complexity and the available sample size. At external validation, calibration curves require sufficiently large samples. Algorithm updating should be considered for appropriate support of clinical practice.ConclusionEfforts are required to avoid poor calibration when developing prediction models, to evaluate calibration when validating models, and to update models when indicated. The ultimate aim is to optimize the utility of predictive analytics for shared decision-making and patient counseling.
Project description:Mycobacterial pathogens adapt to environmental stresses such as nutrient deprivation by entering a non-replicative antibiotic-tolerant state of persistence. Using a biochemically-validated data-driven approach, we identified an adaptive metabolic network underlying the mycobacterial response to starvation in M. tuberculosis, M. bovis BCG and M. smegmatis. All three species show a strong Mg+2-dependence for surviving complete nutrient deprivation, accompanied by a broad phenotypic antibiotic resistance. Multivariate analysis of RNA-seq, metabolic phenotyping and biochemical data revealed substantial metabolic remodelling involving a shift to triacylglycerol utilization with adaptation to the consequent ketoacidosis by upregulation of cytochrome P450s. Paradoxically, the ketosis-driven P450 upregulation generated substantial levels of reactive oxygen species (ROS) yet conferred hypersensitivity to killing by hydrogen peroxide-induced inactivation of the P450s that reduced ROS levels. This emergent property of starvation-induced mycobacterial persistence represents a potentially exploitable vulnerability.
Project description:Ovarian cancer is the leading cause of death among gynecological cancers. It exhibits great heterogeneity in tumor biology and treatment response. Germline mutations of DNA repair genes BRCA1/2 are the fundamental defects in hereditary ovarian cancer that expresses a distinct phenotype of high response rates to platinum agents, improved disease-free intervals and survival rates, and high-grade serous histology. The term "BRCAness" describes the phenotypic traits that some sporadic ovarian tumors share with tumors in BRCA1/2 germline mutation carriers and reflects similar causative molecular abnormalities. BRCA pathway studies and molecular profiling reveal BRCA-related defects in almost half of the cases of ovarian cancer. BRCA-like tumors are particularly sensitive to DNA-damaging agents (e.g., platinum agents) because of inadequate BRCA-mediated DNA repair mechanisms, such as nucleotide-excision repair and homologous recombination (HR). Additional inhibition of other DNA repair pathways leads to synthetic lethality in HR-deficient cells; this has been employed in the treatment of BRCA-like ovarian tumors with poly(ADP-ribose) polymerase inhibitors with promising results. This article presents a comprehensive review of the relevant literature on the role of BRCAness in ovarian cancer with respect to BRCA function, methods of BRCA epigenetic defect detection and molecular profiling, and the implications of BRCA dysfunction in the treatment of ovarian cancer.
Project description:Androgen deprivation therapy (ADT) is the primary systemic therapy for treating locally advanced or metastatic prostate cancer (PCa). Despite its positive effect on PCa patient survival, ADT causes various adverse effects, including increased cardiovascular risk factors and cardiotoxicity. Lifespans extension, early use of ADT, and second-line treatment with next-generation androgen receptor pathway inhibitors would further extend the duration of ADT and possibly increase the risk of ADT-induced cardiotoxicity. Meanwhile, information on the molecular mechanisms underlying ADT-induced cardiotoxicity and measures to prevent it is limited, mainly due to the lack of specifically designed preclinical studies and clinical trials. This review article compiles up-to-date evidence obtained from observational studies and clinical trials, in order to gain new insights for deciphering the association between ADT use and cardiotoxicity. In addition, potential cardioprotective strategies involving GnRH receptors and second messenger cGMP are discussed.
Project description:Interest in the lysosome's potential role in anticancer therapies has recently been appreciated in the field of immuno-oncology. Targeting lysosomes triggers apoptotic pathways, inhibits cytoprotective autophagy, and activates a unique form of apoptosis known as immunogenic cell death (ICD). This mechanism stimulates a local and systemic immune response against dead-cell antigens. Stressors that can lead to ICD include an abundance of ROS which induce lysosome membrane permeability (LMP). Dying cells express markers that activate immune cells. Dendritic cells engulf the dying cell and then present the cell's neoantigens to T cells. The discovery of ICD-inducing agents is important due to their potential to trigger autoimmunity. In this review, we discuss the various mechanisms of activating lysosome-induced cell death in cancer cells specifically and the strategies that current laboratories are using to selectively promote LMP in tumors.