Significant concerns have been raised owing to the rapid global spread of infection and disease caused by the mosquito-borne Zika virus (ZIKV). Recent studies suggest that ZIKV can also be ...transmitted sexually, further increasing the exposure risk for this virus. Associated with this spread is a dramatic increase in cases of microcephaly and additional congenital abnormalities in infants of ZIKV-infected mothers, as well as a rise in the occurrence of Guillain Barre' syndrome in infected adults. Importantly, there are no licensed therapies or vaccines against ZIKV infection. In this study, we generate and evaluate the
efficacy of a novel, synthetic, DNA vaccine targeting the pre-membrane+envelope proteins (prME) of ZIKV. Following initial
development and evaluation studies of the plasmid construct, mice and non-human primates were immunised with this prME DNA-based immunogen through electroporation-mediated enhanced DNA delivery. Vaccinated animals were found to generate antigen-specific cellular and humoral immunity and neutralisation activity. In mice lacking receptors for interferon (IFN)-α/β (designated IFNAR
) immunisation with this DNA vaccine induced, following
viral challenge, 100% protection against infection-associated weight loss or death in addition to preventing viral pathology in brain tissue. In addition, passive transfer of non-human primate anti-ZIKV immune serum protected IFNAR
mice against subsequent viral challenge. This study in NHP and in a pathogenic mouse model supports the importance of immune responses targeting prME in ZIKV infection and suggests that additional research on this vaccine approach may have relevance for ZIKV control and disease prevention in humans.
Significant concerns have arisen over the past 3 y from the increased global spread of the mosquito-borne flavivirus, Zika. Accompanying this spread has been an increase in cases of the devastating ...birth defect microcephaly as well as of Guillain-Barré syndrome in adults in many affected countries. Currently there is no vaccine or therapy for this infection; however, we sought to develop a combination approach that provides more rapid and durable protection than traditional vaccination alone. A novel immune-based prophylaxis/therapy strategy entailing the facilitated delivery of a synthetic DNA consensus prME vaccine along with DNA-encoded anti-ZIKV envelope monoclonal antibodies (dMAb) were developed and evaluated for antiviral efficacy. This immediate and persistent protection strategy confers the ability to overcome shortcomings inherent with conventional active vaccination or passive immunotherapy. A collection of novel dMAbs were developed which were potent against ZIKV and could be expressed in serum within 24-48 h of in vivo administration. The DNA vaccine, from a previous development, was potent after adaptive immunity was developed, protecting against infection, brain and testes pathology in relevant mouse challenge models and in an NHP challenge. Delivery of potent dMAbs protected mice from the same murine viral challenge within days of delivery. Combined injection of dMAb and the DNA vaccine afforded rapid and long-lived protection in this challenge model, providing an important demonstration of the advantage of this synergistic approach to pandemic outbreaks.
Cytokine release and macrophage activation contribute to immunopathology after SARS-CoV-2 infection. We discuss approaches to decrease the morbidity and mortality in patients with COVID-19 by ...repurposing existing drugs previously developed for cancer therapy.
Chimeric antigen receptor (CAR) T cell therapy targeting CD19 has achieved remarkable success in treating B-cell malignancies, however some patients fail to respond due to poor fitness of the ...adoptively transferred T cells. To potentially increase the number of patients that could benefit from CART19 therapy, we investigated whether CRISPR-Cas9-mediated disruption of PDCD1 and/or CTLA-4 in patient T cells could enhance efficacy and restore CART cell function. Indeed, we demonstrate, in both an in vitro model of CART cell dysfunction and xenograft mouse models, that disruption of CTLA-4, but not PDCD1 or PDCD1 and CTLA-4 results in superior CART cell performance evidenced by increased proliferation, cytokine production and superior anti-tumor response. Furthermore, CART19 cells manufactured from T cells lacking CTLA-4 maintain CAR expression on the T cell surface under conditions of chronic antigen exposure, which is a driver of CAR-dysfunction. To understand mechanistically how CTLA-4 disruption contributes to the increased anti-tumor efficacy of CART19 cells we perform transcriptomic analyses and identify upregulated pathways, aligning with the observed therapeutic superiority, including granzyme A and B signaling, cell cycle regulation and cytokine signaling. Moreover, CTLA-4 disrupted CART19 cells display unopposed CD28 signaling, which is observed by pathway analyses. Importantly we confirm the clinical relevance of these results, establishing that depletion of CTLA-4 rescues the function of T cells from leukemia patients that previously failed CART cell treatment and enables the manufacture of potent CART19 products from CLL patient T cells that previously produced an ineffective product. Our findings reveal that disruption of CTLA-4 invigorates dysfunctional patient T cells, providing a strategy for increasing the number of patients that respond to CART19 therapy.
Chimeric antigen receptor (CAR) T cell therapy has achieved remarkable success in hematological malignancies but remains ineffective in solid tumors, due in part to CAR T cell exhaustion in the solid ...tumor microenvironment. To study dysfunction of mesothelin-redirected CAR T cells in pancreatic cancer, we establish a robust model of continuous antigen exposure that recapitulates hallmark features of T cell exhaustion and discover, both in vitro and in CAR T cell patients, that CAR dysregulation is associated with a CD8+ T-to-NK-like T cell transition. Furthermore, we identify a gene signature defining CAR and TCR dysregulation and transcription factors, including SOX4 and ID3 as key regulators of CAR T cell exhaustion. Our findings shed light on the plasticity of human CAR T cells and demonstrate that genetic downmodulation of ID3 and SOX4 expression can improve the efficacy of CAR T cell therapy in solid tumors by preventing or delaying CAR T cell dysfunction.
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•CAR T cells under chronic antigen stimulation show hallmarks of T cell exhaustion•CAR dysregulation is associated with a CD8+ T-to-NK-like T cell transition•CAR T cells with NK-like transition were identified in patients after treatment•Unlike WT CAR T cells, ID3 and SOX4 knockout CAR T cells retain anti-tumor immunity
Continuous antigen exposure drives CAR T cell exhaustion and promotes CD8+ T-to-NK-like T cell transition. Transcription factors ID3 and SOX4 are upregulated during CAR dysfunction and regulate genes associated with exhaustion, including NK receptors. Knocking out ID3 and SOX4 in CAR T cells slows dysfunction and improves anti-tumor immunity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Primary resistance to CD19-directed chimeric antigen receptor T-cell therapy (CART19) occurs in 10% to 20% of patients with acute lymphoblastic leukemia (ALL); however, the mechanisms of this ...resistance remain elusive. Using a genome-wide loss-of-function screen, we identified that impaired death receptor signaling in ALL led to rapidly progressive disease despite CART19 treatment. This was mediated by an inherent resistance to T-cell cytotoxicity that permitted antigen persistence and was subsequently magnified by the induction of CAR T-cell functional impairment. These findings were validated using samples from two CAR T-cell clinical trials in ALL, where we found that reduced expression of death receptor genes was associated with worse overall survival and reduced T-cell fitness. Our findings suggest that inherent dysregulation of death receptor signaling in ALL directly leads to CAR T-cell failure by impairing T-cell cytotoxicity and promoting progressive CAR T-cell dysfunction. SIGNIFICANCE: Resistance to CART19 is a significant barrier to efficacy in the treatment of B-cell malignancies. This work demonstrates that impaired death receptor signaling in tumor cells causes failed CART19 cytotoxicity and drives CART19 dysfunction, identifying a novel mechanism of antigen-independent resistance to CAR therapy.
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•Gene editing using CRIPSR/Cas has the potential to increase anti-tumor efficacy and persistence of adoptively transferred cells.•Allogeneic T cells can be made safer and more effective using ...multiplex genome editing and are already in the clinic.•Base editing and prime editing are promising approaches for advanced T cell engineering but need further optimization of editing efficiency.
T cells engineered to express transgenes such as chimeric antigen receptors (CAR) or modified T cell receptors (TCR) represent a new pillar of cancer therapy. Use of CRISPR/Cas gene–editing tools now allows even stronger and more precise control over the fate and function of engineered T cell therapies, including multiplex genome editing to facilitate use of off-the-shelf allogeneic T cells and novel approaches which have the potential to overcome some of the limitations of canonical Cas9-mediated DNA cleavage. This review summarizes the CRISPR/Cas techniques that have been used in preclinical research and outlines those that currently being tested in clinical trials.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Synthetic receptor signalling has the potential to endow adoptively transferred T cells with new functions that overcome major barriers in the treatment of solid tumours, including the need for ...conditioning chemotherapy
. Here we designed chimeric receptors that have an orthogonal IL-2 receptor extracellular domain (ECD) fused with the intracellular domain (ICD) of receptors for common γ-chain (γ
) cytokines IL-4, IL-7, IL-9 and IL-21 such that the orthogonal IL-2 cytokine elicits the corresponding γ
cytokine signal. Of these, T cells that signal through the chimeric orthogonal IL-2Rβ-ECD-IL-9R-ICD (o9R) are distinguished by the concomitant activation of STAT1, STAT3 and STAT5 and assume characteristics of stem cell memory and effector T cells. Compared to o2R T cells, o9R T cells have superior anti-tumour efficacy in two recalcitrant syngeneic mouse solid tumour models of melanoma and pancreatic cancer and are effective even in the absence of conditioning lymphodepletion. Therefore, by repurposing IL-9R signalling using a chimeric orthogonal cytokine receptor, T cells gain new functions, and this results in improved anti-tumour activity for hard-to-treat solid tumours.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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