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Multilocus variable number tandem repeat analysis (MLVA) is a molecular subtyping technique that remains useful for those without the resources to access whole genome sequencing for the tracking and tracing of bacterial contaminants. Unlike techniques such as multilocus sequence typing (MLST) and pulsed-field gel electrophoresis, MLVA did not emerge as a standardized subtyping method for Listeria monocytogenes, and as a result, there is no reference database of virulent or food-associated MLVA subtypes as there is for MLST-based clonal complexes (CCs). Having previously shown the close congruence of a 5-loci MLVA scheme with MLST, a predictive model was created using the XGBoost machine learning (ML) technique, which enabled the prediction of CCs from MLVA patterns with â¼85% (±4%) accuracy. As well as validating the model on existing data, a straightforward update protocol was simulated for if and when previously unseen subtypes might arise. This article illustrates how ML techniques can be applied with elementary coding skills to add value to previous-generation molecular subtyping data in-built food processing environments.
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Wine is renowned for its rich content of polyphenols, including resveratrol (Res), known for their health promoting properties. Steamed clam with wine, a popular Mediterranean delicacy that highlights the role of wine as a key ingredient. However, despite these benefits, resveratrol's low bioavailability poses challenges. Could the process of steaming together with clam alter the digestive fate of resveratrol from wine? This study explores the potential of proteoglycan-based nanoparticles from freshwater clam (CFNPs) as a delivery vehicle for enhancing the stability and bioavailability of resveratrol, compared with wine and free Res' solution, aiming to elucidate mechanisms facilitating Res' absorption. The results demonstrated that CFNPs can effectively encapsulate Res with an efficiency over 70%, leading to a uniform particle size of 70.5±0.1 nm (PDI < 0.2). Resveratrol loaded in CFNPs (CFNPs-Res) exhibited an improved antioxidant stability under various conditions, retaining over 90% of antioxidant capacity after three-day storage at room temperature. The controlled-release profile of Res loaded in CFNPs fits both first and Higuchi order kinetics and was more desirable than that of wine and the free Res. Examined by the simulated gastrointestinal digestion, CFNPs-Res showed a significantly higher bioaccessibility and antioxidant retention compared to free Res and the wines. The discovery and use of food derived nanoparticles to carry micronutrients and antioxidants could lead to a shift in functional food design and nutritional advice, advocating much more attention on these entities over solely conventional molecules.
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MOTIVATION: Predicting cancer drug response requires a comprehensive assessment of many mutations present across a tumor genome. While current drug response models generally use a binary mutated/unmutated indicator for each gene, not all mutations in a gene are equivalent. RESULTS: Here, we construct and evaluate a series of predictive models based on leading methods for quantitative mutation scoring. Such methods include VEST4 and CADD, which score the impact of a mutation on gene function, and CHASMplus, which scores the likelihood a mutation drives cancer. The resulting predictive models capture cellular responses to dabrafenib, which targets BRAF-V600 mutations, whereas models based on binary mutation status do not. Performance improvements generalize to other drugs, extending genetic indications for PIK3CA, ERBB2, EGFR, PARP1, and ABL1 inhibitors. Introducing quantitative mutation features in drug response models increases performance and mechanistic understanding. AVAILABILITY AND IMPLEMENTATION: Code and example datasets are available at https://github.com/pgwall/qms.
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Antineoplásicos , Mutación , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/tratamiento farmacológico , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Imidazoles/farmacología , Oximas/farmacología , Biología Computacional/métodosRESUMEN
BACKGROUND: Contact tracing is a key component in controlling the spread of COVID-19, however little research has focused on learning from the experiences of contact tracing staff. Harnessing learning from those in this role can provide valuable insights into the process of contact tracing and how best to support staff in this crucial role. METHODS: Thematic analysis was used to analyse 47 semi-structured interviews conducted with contact tracing staff via telephone or Zoom at three time points in 2021: March, May and September-October. RESULTS: Six themes related to the contact tracing role were identified, including training, workforce culture, systems issues, motivation and support. While initially nervous in the role, participants were motivated to contribute to the pandemic response and believed the role provided them with valuable transferable skills. Participants described the training as having improved over time while desiring more proactive training. Sources of frustration included a perceived lack of opportunity for feedback and involvement in process changes, feelings of low autonomy, and a perception of high staff turnover. Participants expressed a need for improved communication of formal emotional supports. Increased managerial support and provision of opportunities for career advancement may contribute to increased motivation among staff. CONCLUSIONS: These findings identify the experiences of contact tracing staff working during the COVID-19 pandemic, and have important implications for the improvement of the contact tracing system. Recommendations based on learning from participants offer suggestions as to how best to support the needs of contact tracing staff during a pandemic response.
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COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Trazado de Contacto , Pandemias , Irlanda/epidemiología , ComunicaciónRESUMEN
Desmosomes are transmembrane protein complexes that contribute to cell-cell adhesion in epithelia and other tissues. Here, we report the discovery of frequent genetic alterations in the desmosome in human cancers, with the strongest signal seen in cutaneous melanoma where desmosomes are mutated in over 70% of cases. In primary but not metastatic melanoma biopsies, the burden of coding mutations on desmosome genes associates with a strong reduction in desmosome gene expression. Analysis by spatial transcriptomics suggests that these expression decreases occur in keratinocytes in the microenvironment rather than in primary melanoma tumor cells. In further support of a microenvironmental origin, we find that loss-of-function knockdowns of the desmosome in keratinocytes yield markedly increased proliferation of adjacent melanocytes in keratinocyte/melanocyte co-cultures. Thus, gradual accumulation of desmosome mutations in neighboring cells may prime melanocytes for neoplastic transformation.
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Listeria monocytogenes is a serious human pathogen and an enduring challenge to control for the ready-to-eat food processing industry. Cost-effective tools that can be deployed by commercial or in-house laboratories to rapidly investigate and resolve contamination events in the built food processing environment are of value to the food industry. Multilocus variable number tandem-repeat analysis (MLVA) is a molecular subtyping method, which along with other same-generation methods such as pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) is being superseded in disease tracking and outbreak investigations by whole-genome sequencing (WGS). In this paper, it is demonstrated that MLVA can continue to play a valuable role as a valid, fast, simple, and cost-effective method to identify and track Listeria monocytogenes subtypes in factory environments, with the method being highly congruent with MLST. Although MLVA does not have the discriminatory power of WGS to identify truly persistent clones, with careful interpretation of results alongside isolate metadata, it remains a powerful tool in situations and locations where WGS may not be readily available to food business operators.
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Listeria monocytogenes , Humanos , Listeria monocytogenes/genética , Tipificación de Secuencias Multilocus/métodos , Repeticiones de Minisatélite , Manipulación de Alimentos/métodos , Industria de Procesamiento de Alimentos , Electroforesis en Gel de Campo Pulsado/métodos , Microbiología de AlimentosRESUMEN
Risk communication is defined as the interactive exchange of information and opinions concerning risk, risk-related factors and risk perceptions amongst all the stakeholders of food safety throughout the risk analysis process. The interactive exchange of information occurs at three different levels i.e. informed level, dialogue level and engagement level. For an effective food safety risk communication (FSRC), it is important that the information should adhere to the core principles of risk communication which are transparency, openness, responsiveness and timeliness. Communication of a food safety risk within all the components of risk communication strategy constitutes a complex network of information flow that can be better understood with the help of a framework. Therefore, a model framework to communicate the risks associated with aflatoxins (AFs) dietary intake has been developed with the aim of (a) creating general awareness amongst public and (b) involving industry stakeholders in the prevention and control of risk. The framework has been motivated by the learnings and best practices outlined in the identified technical guidance documents for risk communication. Risk assessors, risk managers, industry stakeholders and general public have been identified as the major stakeholders for the present framework. Amongst them, industry stakeholders and general public has been selected as the major target audience for risk managers. Moreover, population residing in low- and middle-income countries (LMIC) has been identified as the main target group to reach.
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BACKGROUND: Contact tracing is a key control measure in the response to the COVID-19 pandemic. While quantitative research has been conducted on the psychological impact of the pandemic on other frontline healthcare workers, none has explored the impact on contact tracing staff. METHODS: A longitudinal study was conducted using two repeated measures with contact tracing staff employed in Ireland during the COVID-19 pandemic using two-tailed independent samples t tests and exploratory linear mixed models. RESULTS: The study sample included 137 contact tracers in March 2021 (T1) and 218 in September 2021 (T3). There was an increase from T1 to T3 in burnout related exhaustion (p < 0·001), post-traumatic stress disorder (PTSD) symptom scores (p < 0·001), mental distress (p < 0·01), perceived stress (p < 0·001) and tension and pressure (p < 0·001). In those aged 18-30, there was an increase in exhaustion related burnout (p < 0·01), PTSD symptoms (p < 0·05), and tension and pressure scores (p < 0·05). Additionally, participants with a background in healthcare showed an increase in PTSD symptom scores by T3 (p < 0·001), reaching mean scores equivalent to those of participants who did not have a background in healthcare. CONCLUSIONS: Contact tracing staff working during the COVID-19 pandemic experienced an increase in adverse psychological outcomes. These findings highlight a need for further research on psychological supports required by contact tracing staff with differing demographic profiles.
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COVID-19 , Humanos , COVID-19/epidemiología , Trazado de Contacto , Estudios Longitudinales , Pandemias , Agotamiento Psicológico , Personal de SaludRESUMEN
In 2009, the European Centre for Disease Prevention and Control (ECDC) developed a competency framework to support European Union countries and the European Commission in ensuring a competent public health workforce for Europe. The coronavirus disease (COVID-19) pandemic emphasised the importance of harmonised public health strategies and competencies across international boundaries, specifically for infectious diseases. This perspective presents the process to update the competency framework for applied infectious disease epidemiology, highlighting ECDC's efforts to support countries with using the framework. ECDC commissioned the Association of Schools of Public Health in the European Region (ASPHER) to update the framework through publication and dissemination of a technical report and a self-assessment tool linked to training resources. A mixed methods approach to gather input from experts in relevant specialities included qualitative interviews with 42 experts, workshops with ECDC Technical Advisory Group and an online survey of 212 public health professionals across Europe and beyond. Modifications resulted in 157 core competencies in 23 domains, each mapping to one of six subject areas of importance in applied infectious disease epidemiology. The framework serves as a basis to update the curriculum of the ECDC Fellowship programme with two alternative paths: intervention epidemiology or public health microbiology.
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COVID-19 , Enfermedades Transmisibles , Humanos , Enfermedades Transmisibles/epidemiología , Salud Pública , Curriculum , Europa (Continente)/epidemiologíaRESUMEN
The diagnostic protocol currently used globally to identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is RT-qPCR. The spread of these infections and the epidemiological imperative to describe variation across the virus genome have highlighted the importance of sequencing. SARS-CoV-2 rapid antigen diagnostic tests (RADTs) are designed to detect viral nucleocapsid protein with positive results suggestive of the presence of replicating virus and potential infectivity. In this study, we developed a protocol for recovering SARS-CoV-2 RNA from "spent" RADT devices of sufficient quality that can be used directly for whole virus genome sequencing. The experimental protocol included the spiking of RADTs at different concentrations with viable SARS-CoV-2 variant Alpha (lineage B.1.1.7), lysis for direct use or storage. The lysed suspensions were used for RNA extraction and RT-qPCR. In parallel, we also tested the stability of the viral RNA in the RADTs and the RNA extracted from the RADTs was used as a template for tiling-PCR and whole virus genome sequencing. RNA recovered from RADTs spiked with SARS-CoV-2 was detected through RT-qPCR with Ct values suitable for sequencing and the recovery from RADTs was confirmed after 7 days of storage at both 4 and 20°C. The genomic sequences obtained at each time-point aligned to the strain used for the spiking, demonstrating that sufficient SARS-CoV-2 viral genome can be readily recovered from positive-RADT devices in which the virus has been safely inactivated and genomically conserved. This protocol was applied to obtain whole virus genome sequence from RADTs ran in the field where the omicron variant was detected. The study demonstrated that viral particles of SARS-CoV-2 suitable for whole virus genome sequencing can be recovered from positive spent RADTs, extending their diagnostic utility, as a risk management tool and for epidemiology studies. In large deployment of the RADTs, positive devices could be safely stored and used as a template for sequencing allowing the rapid identification of circulating variants and to trace the source and spread of outbreaks within communities and guaranteeing public health.
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COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Genoma Viral , Humanos , ARN Viral/genética , SARS-CoV-2/genéticaAsunto(s)
Carga Global de Enfermedades , Carne Roja , Dieta , Humanos , Carne , Carne Roja/efectos adversos , Factores de RiesgoRESUMEN
Rapid Antigen Diagnostic Tests (RADTs) for the detection of SARS-CoV-2 offer advantages in that they are cheaper and faster than currently used PCR tests but have reduced sensitivity and specificity. One potential application of RADTs is to facilitate gatherings of individuals, through testing of attendees at the point of, or immediately prior to entry at a venue. Understanding the baseline risk in the tested population is of particular importance when evaluating the utility of applying diagnostic tests for screening purposes. We used incidence data from January and from July-August 2021, periods of relatively high and low levels of infection, to estimate the prevalence of infectious individuals in the community at particular time points and simulated mass gatherings by sampling from a series of age cohorts. Nine different illustrative scenarios were simulated, small (n = 100), medium (n = 1,000) and large (n = 10,000) gatherings each with 3 possible age constructs: mostly younger, mostly older or a gathering with equal numbers from each age cohort. For each scenario, we estimated the prevalence of infectious attendees, then simulated the likely number of positive and negative test results, the proportion of cases detected and the corresponding positive and negative predictive values, and the cost per case identified. Our findings suggest that for each reported case on a given day, there are likely to be 13.8 additional infectious individuals also present in the community. Prevalence ranged from 0.26% for "mostly older" events in July-August, to 2.6% for "mostly younger" events in January. For small events (100 attendees) the expected number of infectious attendees ranged from <1 across all age constructs of attendees in July-August, to 2.6 for "mostly younger" events in January. For large events (10,000 attendees) the expected number of infectious attendees ranged from 27 (95% confidence intervals 12 to 45) for mostly older events in July-August, to 267 (95% confidence intervals 134 to 436) infectious attendees for mostly younger attendees in January. Given rapid changes in SARS-CoV-2 incidence over time, we developed an RShiny app to allow users to run updated simulations for specific events.
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BACKGROUND: Contact tracing is conducted with the primary purpose of interrupting transmission from individuals who are likely to be infectious to others. Secondary analyses of data on the numbers of close contacts of confirmed cases could also: provide an early signal of increases in contact patterns that might precede larger than expected case numbers; evaluate the impact of government interventions on the number of contacts of confirmed cases; or provide data information on contact rates between age cohorts for the purpose of epidemiological modelling. We analysed data from 140,204 close contacts of 39,861 cases in Ireland from 1st May to 1st December 2020. RESULTS: Negative binomial regression models highlighted greater numbers of contacts within specific population demographics, after correcting for temporal associations. Separate segmented regression models of the number of cases over time and the average number of contacts per case indicated that a breakpoint indicating a rapid decrease in the number of contacts per case in October 2020 preceded a breakpoint indicating a reduction in the number of cases by 11 days. CONCLUSIONS: We found that the number of contacts per infected case was overdispersed, the mean varied considerable over time and was temporally associated with government interventions. Analysis of the reported number of contacts per individual in contact tracing data may be a useful early indicator of changes in behaviour in response to, or indeed despite, government restrictions. This study provides useful information for triangulating assumptions regarding the contact mixing rates between different age cohorts for epidemiological modelling.
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COVID-19 , SARS-CoV-2 , Trazado de Contacto , Gobierno , Humanos , IrlandaRESUMEN
Background: Given the unprecedented nature of the COVID-19 pandemic, the Irish health system required the redeployment of public sector staff and the recruitment of dedicated contact tracing staff in the effort to contain the spread of the virus. Contact tracing is crucial for effective disease control and is normally carried out by public health teams. Contact tracing staff are provided with rapid intensive training but are operating in a dynamic environment where processes and advice are adapting continuously. Real-time data is essential to inform strategy, coordinate interconnected processes, and respond to needs . Given that many contact tracers have been newly recruited or redeployed, they may not have significant experience in healthcare and may experience difficulties in managing the anxieties and emotional distress of the public. Aim: (i) identify emerging needs and issues and feed this information back to the Health Service Executive for updates to the COVID-19 Contact Management Programme (CMP); (ii) understand the psychological impact on contact tracers and inform the development of appropriate supports. Methods: We will use a mixed-methods approach. A brief online survey will be administered at up to three time points during 2021 to measure emotional exhaustion, anxiety, general health, and stress of contact tracing staff, identify tracing systems or processes issues, as well as issues of concern and confusion among the public. Interviews will also be conducted with a subset of participants to achieve a more in-depth understanding of these experiences. Observations may be conducted in contact tracing centres to document processes, practices, and explore any local contextual issues. Impact: Regular briefs arising from this research with data, analysis, and recommendations will aim to support the work of the CMP to identify problems and implement solutions. We will deliver regular feedback on systems issues; challenges; and the psychological well-being of contact tracing staff.
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OBJECTIVE: To estimate the proportion of presymptomatic transmission of SARS-CoV-2 infection that can occur, and the timing of transmission relative to symptom onset. SETTING/DESIGN: Secondary analysis of international published data. DATA SOURCES: Meta-analysis of COVID-19 incubation period and a rapid review of serial interval and generation time, which are published separately. PARTICIPANTS: Data from China, the Islamic Republic of Iran, Italy, Republic of Korea, Singapore and Vietnam from December 2019 to May 2020. METHODS: Simulations were generated of incubation period and of serial interval or generation time. From these, transmission times relative to symptom onset, and the proportion of presymptomatic transmission, were estimated. OUTCOME MEASURES: Transmission time of SARS-CoV-2 relative to symptom onset and proportion of presymptomatic transmission. RESULTS: Based on 18 serial interval/generation time estimates from 15 papers, mean transmission time relative to symptom onset ranged from -2.6 (95% CI -3.0 to -2.1) days before infector symptom onset to 1.4 (95% CI 1.0 to 1.8) days after symptom onset. The proportion of presymptomatic transmission ranged from 45.9% (95% CI 42.9% to 49.0%) to 69.1% (95% CI 66.2% to 71.9%). CONCLUSIONS: There is substantial potential for presymptomatic transmission of SARS-CoV-2 across a range of different contexts. This highlights the need for rapid case detection, contact tracing and quarantine. The transmission patterns that we report reflect the combination of biological infectiousness and transmission opportunities which vary according to context.
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COVID-19 , SARS-CoV-2 , China/epidemiología , Trazado de Contacto , Humanos , Irán , Italia , República de Corea , Singapur/epidemiología , Vietnam/epidemiologíaRESUMEN
OBJECTIVES: The aim of this study was to determine the relative infectiousness of asymptomatic SARS-CoV-2 infected persons compared with symptomatic individuals based on a scoping review of available literature. DESIGN: Rapid scoping review of peer-reviewed literature from 1 January to 5 December 2020 using the LitCovid database and the Cochrane library. SETTING: International studies on the infectiousness of individuals infected with SARS-CoV-2. PARTICIPANTS: Studies were selected for inclusion if they defined asymptomatics as a separate cohort distinct from presymptomatics and if they provided a quantitative measure of the infectiousness of asymptomatics relative to symptomatics. PRIMARY OUTCOME MEASURES: PCR result (PCR studies), the rate of infection (mathematical modelling studies) and secondary attack rate (contact tracing studies) - in each case from asymptomatic in comparison with symptomatic individuals. RESULTS: There are only a limited number of published studies that report estimates of relative infectiousness of asymptomatic compared with symptomatic individuals. 12 studies were included after the screening process. Significant differences exist in the definition of infectiousness. PCR studies in general show no difference in shedding levels between symptomatic and asymptomatic individuals; however, the number of study subjects is generally limited. Two modelling studies estimate relative infectiousness to be 0.43 and 0.57, but both of these were more reflective of the infectiousness of undocumented rather than asymptomatic cases. The results from contact tracing studies include estimates of relative infectiousness of 0, but with insufficient evidence to conclude that it is significantly different from 1. CONCLUSIONS: There is considerable heterogeneity in estimates of relative infectiousness highlighting the need for further investigation of this important parameter. It is not possible to provide any conclusive estimate of relative infectiousness, as the estimates from the reviewed studies varied between 0 and 1.
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COVID-19 , SARS-CoV-2 , Estudios de Cohortes , Trazado de Contacto , Humanos , Tamizaje MasivoRESUMEN
The consumer survey reported in this research paper aims to understand how Chinese mothers learn about and confirm the origin of powdered infant formulas (henceforward formulas), their knowledge level and preferences between formulas from different origins. With globalization, dairy companies can source ingredients for domestic production and manufacture finished products across the world. Chinese consumers are now facing a variety of formulas with different brand origin, main ingredient origin ('nai yuan'), manufacturing origin, and country-of-purchase. Drawing on a large representative sample of Chinese mothers who have purchased formulas, we found that most of them had intensively engaged in learning about and confirming formulas' origin through different strategies. However, they may not interpret related cues correctly: a majority of Chinese mothers incorrectly considered the 'main ingredient origin' as the 'manufacturing place' and could not necessarily recognize between 'foreign' and 'domestic' brands. Among formulas from different origins, authentic foreign branded, produced and packaged formulas showed a high popularity in Tier 1 & 2 cities and among more knowledgeable consumers. In low-tier cities, these products were equally popular as domestically branded and produced formulas using imported milk powders and other ingredients. Formulas directly acquired from overseas markets through unofficial channels were least favoured by consumers. The study shows that Chinese consumers' previous one-sided endorsement towards foreign formulas appears to have weakened. Decisions made by formula companies on the origin of the main ingredient and the place of manufacture would influence product attractiveness, and the segments of Chinese consumers to target.
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Comportamiento del Consumidor/estadística & datos numéricos , Etiquetado de Alimentos , Fórmulas Infantiles , Madres/psicología , Adulto , China , Comercio/métodos , Femenino , Humanos , Lactante , Recién Nacido , Percepción , Encuestas y Cuestionarios , Población UrbanaRESUMEN
Oncolytic vaccinia viruses have promising efficacy and safety profiles in cancer therapy. Although antitumor activity can be increased by manipulating viral genes, the relative efficacy of individual modifications has been difficult to assess without side-by-side comparisons. This study sought to compare the initial antitumor activity after intravenous administration of five vaccinia virus variants of the same Western Reserve backbone and thymidine kinase gene deletion in RIP-Tag2 transgenic mice with spontaneous pancreatic neuroendocrine tumors. Tumors had focal regions of infection at 5 days after all viruses. Natural killer (NK) cells were restricted to these sites of infection, but CD8+ T cells and tumor cell apoptosis were widespread and varied among the viruses. Antitumor activity of virus VV-A34, bearing amino acid substitution A34K151E to increase viral spreading, and virus VV-IL2v, expressing a mouse IL2 variant (mIL2v) with attenuated IL2 receptor alpha subunit binding, was similar to control virus VV-GFP. However, antitumor activity was significantly greater after virus VV-A34/IL2v, which expressed mIL2v together with A34K151E mutation and viral B18R gene deletion, and virus VV-GMCSF that expressed mouse GM-CSF. Both viruses greatly increased expression of CD8 antigens Cd8a/Cd8b1 and cytotoxicity genes granzyme A, granzyme B, Fas ligand, and perforin-1 in tumors. VV-A34/IL2v led to higher serum IL2 and greater tumor expression of death receptor ligand TRAIL, but VV-GMCSF led to higher serum GM-CSF, greater expression of leukocyte chemokines and adhesion molecules, and more neutrophil recruitment. Together, the results show that antitumor activity is similarly increased by viral expression of GM-CSF or IL2v combined with additional genetic modifications.
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Apoptosis , Citocinas/metabolismo , Inmunidad , Tumores Neuroendocrinos/terapia , Viroterapia Oncolítica/métodos , Neoplasias Pancreáticas/terapia , Virus Vaccinia/genética , Animales , Linfocitos T CD8-positivos/inmunología , Proliferación Celular , Femenino , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Humanos , Interleucina-2/genética , Interleucina-2/inmunología , Células Asesinas Naturales/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Tumores Neuroendocrinos/metabolismo , Tumores Neuroendocrinos/patología , Tumores Neuroendocrinos/virología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/virología , Células Tumorales CultivadasRESUMEN
Immune checkpoint inhibitors (ICIs) have emerged as promising therapies for the treatment of cancer. However, existing ICIs, namely PD-(L)1 and CTLA-4 inhibitors, generate durable responses only in a subset of patients. TIGIT is a co-inhibitory receptor and member of the DNAM-1 family of immune modulating proteins. We evaluated the prevalence of TIGIT and its cognate ligand, PVR (CD155), in human cancers by assessing their expression in a large set of solid tumors. TIGIT is expressed on CD4+ and CD8+ TILs and is upregulated in tumors compared to normal tissues. PVR is expressed on tumor cells and tumor-associated macrophages from multiple solid tumors. We explored the therapeutic potential of targeting TIGIT by generating COM902, a fully human anti-TIGIT hinge-stabilized IgG4 monoclonal antibody that binds specifically to human, cynomolgus monkey, and mouse TIGIT, and disrupts the binding of TIGIT with PVR. COM902, either alone or in combination with a PVRIG (COM701) or PD-1 inhibitor, enhances antigen-specific human T cell responses in-vitro. In-vivo, a mouse chimeric version of COM902 in combination with an anti-PVRIG or anti-PD-L1 antibody inhibited tumor growth and increased survival in two syngeneic mouse tumor models. In summary, COM902 enhances anti-tumor immune responses and is a promising candidate for the treatment of advanced malignancies.