RESUMEN
Background and purpose: Peer review is an important component of quality assurance in radiotherapy. To our knowledge, there are no studies reporting on the feasibility and outcomes of the peer review process for magnetic resonance (MR) guided radiotherapy (MRgRT) on the MR linear accelerator (MR-Linac) despite the planning complexity involved and its evolving clinical indications. This study aimed to quantify the rate of change in treatment plans post-peer review and the time and resources required. Materials and methods: Fifty-five cases presented at weekly MR-Linac peer review meetings across two centres from 8 June to 21 September 2023 were prospectively collected. Cases were analysed to determine the rate and extent of plan changes based on the Peer Review Audit Tool for radiation oncology (PRAT) developed by the Royal Australian and New Zealand College of Radiologists (RANZCR). Results: Peer review resulted in changes to 36.4 % of treatment plans (n = 20), with 3.6 % (n = 2) having major changes requiring deferment of treatment. The most frequent changes were to organs at risk (OAR) volumes involving both delineation and increased OAR sparing (16.4 %, n = 9), total dose and fractionation (10.9 %, n = 6) and target volume dose coverage (5.5 %, n = 3). Patients with SBRT plans (39.1 % cf 22.2 %), oligometastatic/oligoprogressive sites (38.1 % cf 30.7 %) and reirradiation cases (41.2 % cf 34.2 %) had higher rates of change. Cases took a mean of 7 min (range 2-15 minutes) to discuss. Conclusion: The high rates of plan changes support the value of peer review in MRgRT. We recommend, where possible that all MRgRT cases, particularly those involving SBRT plans, oligometastatic/oligoprogressive sites, and/or reirradiation, be subject to peer review.
RESUMEN
Rationale and objectives: A new microcatheter was recently developed claiming to reduce beads reflux in drug-eluting bead transarterial chemoembolization (DEB-TACE). The aim of this study was to compare the reflux control microcatheter ability versus a standard microcatheter for TACE treatment in patients with hepatocellular carcinoma. Material and methods: Patients were prospectively included between November 2017 and February 2022. They received a DEB-TACE treatment with charged radiopaque beads using standard microcatheters or the SeQure reflux control microcatheter (Guerbet, France) and were assigned respectively to a control and a test group. Beads distribution mismatch was evaluated between the targeted territory on treatment planning CBCT and beads' spontaneous opacities on the post-intervention CBCT and the 1-month CT scanner. Results: Twenty-three patients (21 men, median age 64 years [12.5 years]) with 37 hepatocellular carcinoma nodules were treated. The control group consisted of 13 patients - 19 nodules, while the test group included ten patients - 18 nodules. Non target embolization (NTE) was found in 20 % (2/10) of patients in the test group and 85 % (11/13) in the control group. NTE involved only an adjacent segment in the test group while it affected the adjacent biliary sector or even the contralateral liver lobe in the control group. No complication linked to NTE was found in the test group, while it led to one case of ischemic cholangitis and another case of biloma in the control group. Conclusion: The reflux control microcatheter may be efficient in reducing NTE and thus eventual adverse events in comparison to standard of care end-hole microcatheters.
RESUMEN
Background and purpose: Treatment planning for MR-guided stereotactic body radiotherapy (SBRT) for pancreatic tumors can be challenging, leading to a wide variation of protocols and practices. This study aimed to harmonize treatment planning by developing a consensus planning protocol for MR-guided pancreas SBRT on a 1.5 T MR-Linac. Materials and methods: A consortium was founded of thirteen centers that treat pancreatic tumors on a 1.5 T MR-Linac. A phased planning exercise was conducted in which centers iteratively created treatment plans for two cases of pancreatic cancer. Each phase was followed by a meeting where the instructions for the next phase were determined. After three phases, a consensus protocol was reached. Results: In the benchmarking phase (phase I), substantial variation between the SBRT protocols became apparent (for example, the gross tumor volume (GTV) D99% ranged between 36.8 - 53.7 Gy for case 1, 22.6 - 35.5 Gy for case 2). The next phase involved planning according to the same basic dosimetric objectives, constraints, and planning margins (phase II), which led to a large degree of harmonization (GTV D99% range: 47.9-53.6 Gy for case 1, 33.9-36.6 Gy for case 2). In phase III, the final consensus protocol was formulated in a treatment planning system template and again used for treatment planning. This not only resulted in further dosimetric harmonization (GTV D99% range: 48.2-50.9 Gy for case 1, 33.5-36.0 Gy for case 2) but also in less variation of estimated treatment delivery times. Conclusion: A global consensus protocol has been developed for treatment planning for MR-guided pancreatic SBRT on a 1.5 T MR-Linac. Aside from harmonizing the large variation in the current clinical practice, this protocol can provide a starting point for centers that are planning to treat pancreatic tumors on MR-Linac systems.
RESUMEN
Metabolic programming is intricately linked to the anti-tumor properties of T cells. To study the metabolic pathways associated with increased anti-tumor T cell function, we utilized a metabolomics approach to characterize three different CD8+ T cell subsets with varying degrees of anti-tumor activity in murine models, of which IL-22-producing Tc22 cells displayed the most robust anti-tumor activity. Tc22s demonstrated upregulation of the pantothenate/coenzyme A (CoA) pathway and a requirement for oxidative phosphorylation (OXPHOS) for differentiation. Exogenous administration of CoA reprogrammed T cells to increase OXPHOS and adopt the CD8+ Tc22 phenotype independent of polarizing conditions via the transcription factors HIF-1α and the aryl hydrocarbon receptor (AhR). In murine tumor models, treatment of mice with the CoA precursor pantothenate enhanced the efficacy of anti-PDL1 antibody therapy. In patients with melanoma, pre-treatment plasma pantothenic acid levels were positively correlated with the response to anti-PD1 therapy. Collectively, our data demonstrate that pantothenate and its metabolite CoA drive T cell polarization, bioenergetics, and anti-tumor immunity.
Asunto(s)
Coenzima A , Subgrupos de Linfocitos T , Animales , Linfocitos T CD8-positivos , Diferenciación Celular , Coenzima A/metabolismo , Humanos , Activación de Linfocitos , Ratones , Subgrupos de Linfocitos T/metabolismoRESUMEN
BACKGROUND: To avoid false-positive findings and detect cell-type specific associations in methylation and transcription investigations with bulk samples, it is critical to know the proportions of the major cell-types. RESULTS: We present a novel approach that allows for precise estimation of cell-type proportions using only a few highly informative methylation markers. The most reliable estimates were obtained with 17 amplicons (34 CpGs) using the MuSiC estimator, for which the average correlations between the estimated and the true cell-type proportions were 0.889. Furthermore, the estimates were not significantly different from the true values (P = 0.95) indicating that the estimator is unbiased and the standard deviation of the estimates further indicate high precision. Moreover, the overall variability of the estimates as measured by the Root Mean Squared Error (RMSE), which is a function of both bias and precision, was low (mean RMSE = 0.038). Taken together, these results indicate that the approach produced reliable estimates that are both unbiased and highly precise. CONCLUSION: This cost-effective approach for estimating cell-type proportions in bulk samples allows for enhanced targeted analysis, which in turn will minimize the risk of reporting false-positive findings and allowing for detection of cell-type specific associations. The approach is applicable across platforms and can be extended to assess cell-type proportions for various tissues.
RESUMEN
Dendritic cells are sentinels of the immune system and represent a key cell in the activation of the adaptive immune response. Hypoxia-inducible factor 1 alpha (HIF-1α)-a crucial oxygen sensor stabilized during hypoxic conditions-has been shown to have both activating and inhibitory effects in immune cells in a context- and cell-dependent manner. Previous studies have demonstrated that in some immune cell types, HIF-1α serves a pro-inflammatory role. Genetic deletion of HIF-1α in macrophages has been reported to reduce their pro-inflammatory function. In contrast, loss of HIF-1α enhanced the pro-inflammatory activity of dendritic cells in a bacterial infection model. In this study, we aimed to further clarify the effects of HIF-1α in dendritic cells. Constitutive expression of HIF-1α resulted in diminished immunostimulatory capacity of dendritic cells in vivo, while conditional deletion of HIF-1α in dendritic cells enhanced their ability to induce a cytotoxic T cell response. HIF-1α-expressing dendritic cells demonstrated increased production of inhibitory mediators including IL-10, iNOS and VEGF, which correlated with their reduced capacity to drive effector CD8+ T cell function. Altogether, these data reveal that HIF-1α can promote the anti-inflammatory functions of dendritic cells and provides insight into dysfunctional immune responses in the context of HIF-1α activation.
Asunto(s)
Biomarcadores/metabolismo , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/citología , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Animales , Células Cultivadas , Células Dendríticas/metabolismo , Técnicas de Inactivación de Genes , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Interleucina-10/metabolismo , Ratones , Óxido Nítrico Sintasa de Tipo II/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Regulatory T cells are integral to the regulation of autoimmune and anti-tumor immune responses. However, several studies have suggested that changes in T cell signaling networks can result in T cells that are resistant to the suppressive effects of regulatory T cells. Here, we investigated the role of Cbl-b, an E3 ubiquitin ligase, in establishing resistance to Treg-mediated suppression. We found that the absence of Cbl-b, a negative regulator of multiple TCR signaling pathways, rendered T cells impartial to Treg suppression by regulating cytokine networks leading to improved anti-tumor immunity despite the presence of Treg cells in the tumor. Specifically, Cbl-b KO CD4+FoxP3- T cells hyper-produced IL-2 and together with IL-2 Rα upregulation served as an essential mechanism to escape suppression by Treg cells. Furthermore, we report that IL-2 serves as the central molecule required for cytokine-induced Treg resistance. Collectively our data emphasize the role of IL-2 as a key mechanism that renders CD4+ T cells resistant to the inhibitory effects of Treg cells.
Asunto(s)
Interleucina-2 , Linfocitos T Reguladores , Animales , Interleucina-2/genética , Subunidad alfa del Receptor de Interleucina-2 , Ratones Endogámicos C57BL , Transducción de Señal , Linfocitos T Reguladores/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Nanomedicine drug delivery systems are capable of transporting significant payloads to solid tumors. However, only a modest increase in antitumor efficacy relative to the standard of care has been observed. In this study, we demonstrate that a single dose of radiation or mild hyperthermia can substantially improve tumor uptake and distribution of nanotherapeutics, resulting in improved treatment efficacy. The delivery of nanomedicine was driven by a reduction in interstitial fluid pressure (IFP) and small perturbation of steady-state fluid flow. The transient effects on fluid dynamics in tumors with high IFP was also shown to dominate over immune cell endocytic capacity, another mechanism suspected of improving drug delivery. Furthermore, we demonstrate the specificity of this mechanism by showing that delivery of nanotherapeutics to low IFP tumors with high leukocyte infiltration does not benefit from pretreatment with radiation or heat. These results demonstrate that focusing on small perturbations to steady-state fluid dynamics, rather than large sustained effects or uncertain immune cell recruitment strategies, can impart a vulnerability to tumors with high IFP and enhance nanotherapeutic drug delivery and treatment efficacy.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/análogos & derivados , Sistemas de Liberación de Medicamentos , Líquido Extracelular/efectos de los fármacos , Calor , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Nanomedicina/métodos , Animales , Antibióticos Antineoplásicos/administración & dosificación , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Líquido Extracelular/metabolismo , Femenino , Humanos , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones SCID , Polietilenglicoles/administración & dosificación , Polietilenglicoles/farmacología , Relación Estructura-Actividad , Tomografía Computarizada por Rayos X , Rayos XRESUMEN
The decision between T cell activation and tolerance is governed by the spatial and temporal integration of diverse molecular signals and events occurring downstream of TCR and costimulatory or coinhibitory receptor engagement. The PI3K-protein kinase B (PKB; also known as Akt) signaling pathway is a central axis in mediating proximal signaling events of TCR and CD28 engagement in T cells. Perturbation of the PI3K-PKB pathway, or the loss of negative regulators of T cell activation, such as the E3 ubiquitin ligase Cbl-b, have been reported to lead to increased susceptibility to autoimmunity. In this study, we further examined the molecular pathway linking PKB and Cbl-b in murine models. Our data show that the protein kinase GSK-3, one of the first targets identified for PKB, catalyzes two previously unreported phosphorylation events at Ser476 and Ser480 of Cbl-b. GSK-3 inactivation by PKB abrogates phosphorylation of Cbl-b at these two sites and results in reduced Cbl-b protein levels. We further show that constitutive activation of PKB in vivo results in a loss of tolerance that is mediated through the downregulation of Cbl-b. Altogether, these data indicate that the PI3K-PKB-GSK-3 pathway is a novel regulatory axis that is important for controlling the decision between T cell activation and tolerance via Cbl-b.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Glucógeno Sintasa Quinasa 3/fisiología , Tolerancia Inmunológica/fisiología , Activación de Linfocitos/fisiología , Proteínas Proto-Oncogénicas c-cbl/metabolismo , Subgrupos de Linfocitos T/enzimología , Secuencia de Aminoácidos , Animales , Autoinmunidad/fisiología , Activación Enzimática , Regulación de la Expresión Génica/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Fosfatidilinositol 3-Quinasas/fisiología , Fosforilación , Fosfoserina/metabolismo , Isoformas de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas c-akt/fisiología , Alineación de Secuencia , Transducción de Señal/fisiología , Especificidad de la Especie , Organismos Libres de Patógenos Específicos , Subgrupos de Linfocitos T/inmunologíaRESUMEN
The polarity protein Scribble (SCRIB) regulates apical-basal polarity, directional migration and tumour suppression in Drosophila and mammals. Here we report that SCRIB is an important regulator of myeloid cell functions including bacterial infection and inflammation. SCRIB interacts directly with the NADPH oxidase (NOX) complex in a PSD95/Dlg/ZO-1 (PDZ)-domain-dependent manner and is required for NOX-induced reactive oxygen species (ROS) generation in culture and in vivo. On bacterial infection, SCRIB localized to phagosomes in a leucine-rich repeat-dependent manner and promoted ROS production within phagosomes to kill bacteria. Unexpectedly, SCRIB loss promoted M1 macrophage polarization and inflammation. Thus, SCRIB uncouples ROS-dependent bacterial killing activity from M1 polarization and inflammatory functions of macrophages. Modulating the SCRIB-NOX pathway can therefore identify ways to manage infection and inflammation with implications for chronic inflammatory diseases, sepsis and cancer.
Asunto(s)
Membrana Celular/metabolismo , Polaridad Celular/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Proteínas de la Membrana/metabolismo , NADPH Oxidasas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Humanos , Inflamación/metabolismo , Ratones , Células Mieloides/metabolismo , Fagosomas/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Infections with HIV, hepatitis B virus, and hepatitis C virus can turn into chronic infections, which currently affect more than 500 million patients worldwide. It is generally thought that virus-mediated T-cell exhaustion limits T-cell function, thus promoting chronic disease. Here we demonstrate that natural killer (NK) cells have a negative impact on the development of T-cell immunity by using the murine lymphocytic choriomeningitis virus. NK cell-deficient (Nfil3(-/-), E4BP4(-/-)) mice exhibited a higher virus-specific T-cell response. In addition, NK cell depletion caused enhanced T-cell immunity in WT mice, which led to rapid virus control and prevented chronic infection in lymphocytic choriomeningitis virus clone 13- and reduced viral load in DOCILE-infected animals. Further experiments showed that NKG2D triggered regulatory NK cell functions, which were mediated by perforin, and limited T-cell responses. Therefore, we identified an important role of regulatory NK cells in limiting T-cell immunity during virus infection.
Asunto(s)
Infecciones por Arenaviridae/inmunología , Linfocitos T CD8-positivos/inmunología , Enfermedad Crónica , Enfermedades Transmisibles/inmunología , Inmunidad Celular/inmunología , Células Asesinas Naturales/inmunología , Activación de Linfocitos/inmunología , Virus de la Coriomeningitis Linfocítica , Análisis de Varianza , Animales , Pruebas Inmunológicas de Citotoxicidad , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Técnicas Histológicas , Interferón-alfa/metabolismo , Ratones , Subfamilia K de Receptores Similares a Lectina de Células NK/inmunología , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
OBJECTIVE: To determine whether treatment with an antiresorptive drug in combination with an antiinflammatory drug reduces periarticular bone and soft tissue adaptations associated with the progression of posttraumatic secondary osteoarthritis (OA). METHODS: We used in vivo microfocal computed tomography (micro-CT) to map bony adaptations and in vivo micro-magnetic resonance imaging (micro-MRI) to examine joint inflammation in a rat model of surgically induced OA secondary to knee triad injury. We examined the arthroprotective effects of the bisphosphonates alendronate and risedronate and the nonsteroidal antiinflammatory drug (NSAID) meloxicam. RESULTS: Micro-CT revealed reduced levels of periarticular trabecular bone loss in animals with knee triad injury treated with the bisphosphonate drugs alendronate or risedronate, or the NSAID meloxicam, compared with untreated animals. Alendronate treatment reduced bony osteophyte development. While risedronate as a monotherapy did not positively impact osteophytogenesis, combination therapy with risedronate and meloxicam reduced osteophyte severity somewhat. Micro-MRI revealed an increased, diffuse water signal in the epiphyses of untreated rats with knee triad injury 8 weeks after surgery, suggestive of a bone marrow lesion-like stimulus. In contrast, meloxicam-treated rats showed a significant reduction in fluid signal compared with both bisphosphonate-treated groups 8 weeks after surgery. Histologic analysis qualitatively confirmed the chondroprotective effect of both bisphosphonate treatments, showing fewer degradative changes compared with untreated rats with knee triad injury. CONCLUSION: Our findings indicate that select combinations of bisphosphonate and NSAID drug therapy in the early stages of secondary OA preserve trabecular bone mass and reduce the impact of osteophytic bony adaptations and bone marrow lesion-like stimulus. Bisphosphonate and NSAID therapy may be an effective disease-modifying drug regimen if administered early after the initial injury.
Asunto(s)
Alendronato/farmacología , Antiinflamatorios no Esteroideos/farmacología , Conservadores de la Densidad Ósea/farmacología , Ácido Etidrónico/análogos & derivados , Osteoartritis de la Rodilla/tratamiento farmacológico , Tiazinas/farmacología , Tiazoles/farmacología , Animales , Modelos Animales de Enfermedad , Quimioterapia Combinada , Epífisis/química , Epífisis/efectos de los fármacos , Ácido Etidrónico/farmacología , Femenino , Fémur/diagnóstico por imagen , Fémur/efectos de los fármacos , Fémur/patología , Imagen por Resonancia Magnética/métodos , Meloxicam , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/patología , Osteofito/tratamiento farmacológico , Ratas , Ratas Sprague-Dawley , Ácido Risedrónico , Rodilla de Cuadrúpedos/efectos de los fármacos , Rodilla de Cuadrúpedos/patología , Rodilla de Cuadrúpedos/cirugía , Tibia/diagnóstico por imagen , Tibia/efectos de los fármacos , Tibia/patología , Tomografía Computarizada por Rayos X/métodos , Agua/químicaRESUMEN
Despite considerable excitement over the potential functional significance of copy-number variants (CNVs), we still lack knowledge of the fine-scale architecture of the large majority of CNV regions in the human genome. In this study, we used a high-resolution array-based comparative genomic hybridization (aCGH) platform that targeted known CNV regions of the human genome at approximately 1 kb resolution to interrogate the genomic DNAs of 30 individuals from four HapMap populations. Our results revealed that 1020 of 1153 CNV loci (88%) were actually smaller in size than what is recorded in the Database of Genomic Variants based on previously published studies. A reduction in size of more than 50% was observed for 876 CNV regions (76%). We conclude that the total genomic content of currently known common human CNVs is likely smaller than previously thought. In addition, approximately 8% of the CNV regions observed in multiple individuals exhibited genomic architectural complexity in the form of smaller CNVs within larger ones and CNVs with interindividual variation in breakpoints. Future association studies that aim to capture the potential influences of CNVs on disease phenotypes will need to consider how to best ascertain this previously uncharacterized complexity.