TLR-induced maturation of dendritic cells (DCs) leads to the production of proinflammatory cytokines as well as the upregulation of various molecules involved in T cell activation. These are believed ...to be the critical events that account for the induction of the adaptive immune response. In this study, we have examined the role of miR-155 in DC function and the induction of immunity. Using a model in which the transfer of self-Ag-pulsed, TLR-matured DCs can induce a functional CD8 T cell response and autoimmunity, we find that DCs lacking miR-155 have an impaired ability to break immune tolerance. Importantly, transfer of self- Ag-pulsed DCs overexpressing miR-155 was sufficient to break tolerance in the absence of TLR stimuli. Although these unstimulated DCs induced T cell function in vivo, there was no evidence for the upregulation of costimulatory ligands or cytokine secretion. Further analysis showed that miR-155 influenced the level of the phosphatase SHIP1 in DCs and that the lack of SHIP1 in DCs was sufficient to break T cell tolerance in vivo, again in the absence of TLR-induced DC maturation. Our study demonstrates that the overexpression of miR-155 in DCs is a critical event that is alone sufficient to break self-tolerance and promote a CD8-mediated autoimmune response in vivo. This process is independent of the induction of conventional DC maturation markers, indicating that miR-155 regulation of SHIP represents a unique axis that regulates DC function in vivo.
BackgroundAdoptive T cell therapy (ACT) is reaching its potential in multiple malignancies. However, anti-tumor T cell responses can be attenuated by suppressive cells in the tumor microenvironment, ...such as CD4+FoxP3+ regulatory T (Treg) cells. Depletion of Treg cells can be technically challenging in ACT and may be associated with unwanted adverse effects. Alternatively, studies suggest that specific modifications in T cell signaling network may render T cells resistant to regulation by Treg cells. Here, we investigated the role of Casitas B- Lineage Lymphoma-b (Cbl-b), an E3 ubiquitin ligase and a negative regulator of TCR signaling pathways, in rendering CD8+ T cells resistant to the effects of Treg cells to bolster ACT.MethodsIn vitro stimulated Cbl-b+/+ or Cbl-b-/- Thy1.1+ P14 TCR-transgenic CD8+ T cells were adoptively transferred into B16-gp33 melanoma-bearing Thy1.2+ FoxP3-GFP/DTR transgenic mice treated with or without diphtheria toxin (n = 15). Tumor size and overall survival were measured. Congenically labelled T cells from tumor, draining lymph node, and spleen were comprehensively profiled using flow cytometry. To further examine the biological mechanism of Treg resistance, we performed in vitro Treg suppression assays and RNA-sequencing.ResultsAdoptively transferred tumor-specific Cbl-b-/- effector CD8+ T cells mediated superior control over tumor growth and increased overall survival in comparison to the wild-type counterpart. Depletion of FoxP3+ cells increased the quantity and percentage of CD25+ 4-1BB+ expressing P14 Thy1.1+ CD8+ T cells in the tumor, whereas the effect of FoxP3+ cell depletion was negligible with Cbl-b deficient CD8+ T cells. Cbl-b deficiency also attenuated sensitivity to Treg cell-mediated suppression in vitro. Transcriptomic analyses suggested that Cbl-b regulates pathways associated with cytokine production and cellular proliferation. Specifically, hyper-secretion of IFN-γ by Cbl-b deficient CD8+ T cells attenuated suppression by Treg cells. In murine models of adoptive T cell therapy, Cbl-b deficient CD8+ T cells were less susceptible to suppression by Treg cells in the tumor through the effects of IFN-γ.ConclusionsWe demonstrate that adoptively transferred effector CD8+ T cells are susceptible to regulation by Treg cells in the tumor, and that ablation of Cbl-b abrogates Treg cell-mediated suppression. We highlight the therapeutic implications of targeting Cbl-b in the context of ACT.AcknowledgementsWe would like to thank Dr. Tak Mak and Dr. Naoto Hirano for their suggestions and insights for this project.
Regulatory T cells (Treg) are an integral component of the adaptive immune system that negatively affect antitumor immunity. Here, we investigated the role of the E3 ubiquitin ligase casitas ...B-lineage lymphoma-b (Cbl-b) in establishing CD8+ T-cell resistance to Treg-mediated suppression to enhance antitumor immunity. Transcriptomic analyses suggested that Cbl-b regulates pathways associated with cytokine signaling and cellular proliferation. We showed that the hypersecretion of IFNγ by Cbl-b-deficient CD8+ T cells selectively attenuated CD8+ T-cell suppression by Tregs. Although IFNγ production by Cbl-b-deficient T cells contributed to phenotypic alterations in Tregs, the cytokine did not attenuate the suppressive function of Tregs. Instead, IFNγ had a profound effect on CD8+ T cells by directly upregulating interferon-stimulated genes and modulating T-cell activation. In murine models of adoptive T-cell therapy, Cbl-b-deficient T cells elicited superior antitumor immune response. Furthermore, Cbl-b-deficient CD8+ T cells were less susceptible to suppression by Tregs in the tumor through the effects of IFNγ. Collectively, this study demonstrates that the hypersecretion of IFNγ serves as a key mechanism by which Cbl-b-deficient CD8+ T cells are rendered resistant to Tregs. See related Spotlight by Wolf and Baier, p. 370.
Recruiting participants to clinical trials is an ongoing challenge, and relatively little is known about what recruitment strategies lead to better recruitment. Recruitment interventions can be ...considered complex interventions, often involving multiple components, targeting a variety of groups, and tailoring to different groups. We used the Template for Intervention Description and Replication (TIDieR) reporting checklist (which comprises 12 items recommended for reporting complex interventions) to guide the assessment of how recruitment interventions are described. We aimed to (1) examine to what extent we could identify information about each TIDieR item within recruitment intervention studies, and (2) observe additional detail for each item to describe useful variation among these studies.
We identified randomized, nested recruitment intervention studies providing recruitment or willingness to participate rates from two sources: a Cochrane review of trials evaluating strategies to improve recruitment to randomized trials, and the Online Resource for Research in Clinical triAls database. First, we assessed to what extent authors reported information about each TIDieR item. Second, we developed descriptive categorical variables for 7 TIDieR items and extracting relevant quotes for the other 5 items.
We assessed 122 recruitment intervention studies. We were able to extract information relevant to most TIDieR items (e.g., brief rationale, materials, procedure) with the exception of a few items that were only rarely reported (e.g., tailoring, modifications, planned/actual fidelity). The descriptive variables provided a useful overview of study characteristics, with most studies using various forms of informational interventions (55%) delivered at a single time point (90%), often by a member of the research team (59%) in a clinical care setting (41%).
Our TIDieR-based variables provide a useful description of the core elements of complex trial recruitment interventions. Recruitment intervention studies report core elements of complex interventions variably; some process elements (e.g., mode of delivery, location) are almost always described, while others (e.g., duration, fidelity) are reported infrequently, with little indication of a reason for their absence. Future research should explore whether these TIDieR-based variables can form the basis of an approach to better reporting of elements of successful recruitment interventions.
This study aimed to systematically review evidence on the cost-effectiveness of chimeric antigen receptor T-cell (CAR-T) therapies for patients with cancer.
Electronic databases were searched in ...October 2022 and updated in September 2023. Systematic reviews, health technology assessments, and economic evaluations that compared costs and effects of CAR-T therapy in patients with cancer were included. Two reviewers independently screened studies, extracted data, synthesized results, and critically appraised studies using the Philips checklist. Cost data were presented in 2022 US dollars.
Our search yielded 1809 records, 47 of which were included. Most of included studies were cost-utility analysis, published between 2018 and 2023, and conducted in the United States. Tisagenlecleucel, axicabtagene ciloleucel, idecabtagene vicleucel, ciltacabtagene autoleucel, lisocabtagene maraleucel, brexucabtagene autoleucel, and relmacabtagene autoleucel were compared with various standard of care chemotherapies. The incremental cost-effectiveness ratio (ICER) for CAR-T therapies ranged from $9424 to $4 124 105 per quality-adjusted life-year (QALY) in adults and from $20 784 to $243 177 per QALY in pediatric patients. Incremental cost-effectiveness ratios were found to improve over longer time horizons or when an earlier cure point was assumed. Most studies failed to meet the Philips checklist due to a lack of head-to-head comparisons and uncertainty surrounding CAR-T costs and curative effects.
CAR-T therapies were more expensive and generated more QALYs than comparators, but their cost-effectiveness was uncertain and dependent on patient population, cancer type, and model assumptions. This highlights the need for more nuanced economic evaluations and continued research to better understand the value of CAR-T therapies in diverse patient populations.
•Chimeric antigen receptor T-cell (CAR-T) therapies are a group of novel cancer therapeutics that have shown significant promise in the treatment of patients whose disease has relapsed or become refractory to treatment. However, these come at a significantly higher price than existing therapies, raising questions of their value for money.•This systematic review provides a comprehensive summary and critical evaluation of the available evidence on the economic value of CAR-T therapies. It encompasses a review of 47 studies that compare 7 distinct CAR-T therapies against standard cancer care practices, covering both pediatric and adult patient populations.•The findings indicate that CAR-T therapies tend to be more costly, but also more effective than their comparator treatments. However, the cost-effectiveness estimates for these therapies are highly uncertain, influenced by a range of factors including patient demographics, specific cancer types being treated, and underlying assumptions of the economic models used. Given the evolving evidence on the safety and efficacy of CAR-T therapies, it is crucial to update estimates as new evidence becomes available.
The book is a handbook of cultural discourse analysis, a theory developed by Donal Carbaugh, and celebration of his work. The book features an explanation of the theory and sixteen chapters using the ...theory to examine communication issues across the globe.
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