Publications by authors named "Bethune M"

Cleft lip and/or palate (CL/CP) is the most common congenital craniofacial anomaly and parents often ask, "how did this happen?" Patients and families may benefit from access to a multidisciplinary team (MDT) from prenatal diagnosis into early adulthood. Multiple factors can contribute to the development of a cleft. We discuss the epidemiology and risk factors that increase the likelihood of having a newborn with a cleft.

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Neoantigens are peptides derived from non-synonymous mutations presented by human leukocyte antigens (HLAs), which are recognized by antitumour T cells. The large HLA allele diversity and limiting clinical samples have restricted the study of the landscape of neoantigen-targeted T cell responses in patients over their treatment course. Here we applied recently developed technologies to capture neoantigen-specific T cells from blood and tumours from patients with metastatic melanoma with or without response to anti-programmed death receptor 1 (PD-1) immunotherapy.

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Article Synopsis
  • T cell receptors (TCRs) are crucial for T cells to detect cancer cell mutations, and researchers used a CRISPR-Cas9 method to edit TCR genes in a clinical trial setting.
  • Sixteen patients with advanced solid cancers received personalized T cell therapies featuring engineered neoTCRs, with most participants experiencing either stable disease or disease progression.
  • The study confirmed that it is feasible to create multiple engineered TCRs, showing the safety and effectiveness of infusing gene-edited T cells that can successfully target tumors.
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Border Disease (BD) is a major sheep disease characterized by immunosuppression, congenital disorders, abortion, and birth of lambs persistently infected (PI) by Border Disease Virus (BDV). Control measures are based on the elimination of PI lambs, biosecurity, and frequent vaccination which aims to prevent fetal infection and birth of PI. As there are no vaccines against BDV, farmers use vaccines directed against the related Bovine Viral Diarrhea Virus (BVDV).

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Background: The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recently recommended offering genetic counseling and diagnostic testing for enlarged nuchal translucency at ≥3.0 mm, regardless of previous negative screening with noninvasive prenatal testing.

Objective: This study aimed to perform a population-based, individual record linkage study to determine the optimal definition of an enlarged nuchal translucency for the detection of atypical chromosome abnormalities.

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Study Question: What is the frequency of major chromosome abnormalities in a population-based diagnostic data set of genomic tests performed on miscarriage, fetal and infant samples in a state with >73 000 annual births?

Summary Answer: The overall frequency of major chromosome abnormalities in the entire cohort was 28.2% (2493/8826), with a significant decrease in the detection of major chromosome abnormalities with later developmental stage, from 50.9% to 21.

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Objectives: To explore the association between timing of diagnosis of common autosomal trisomies, maternal age, and socio-economic status (SES).

Design: Retrospective study of cytogenetic diagnoses of trisomy 21 (T21), trisomy 18 (T18), and trisomy 13 (T13) in Victoria, Australia, in 2015 to 2016, stratified by timing (prenatal less than 17 weeks gestation, prenatal including or greater than or 17 weeks gestation, and postnatal before 12 months of age), maternal age, and SES region. Utilisation of prenatal testing following a live-born T21 infant was ascertained via record linkage.

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Objectives: To perform individual record linkage of women undergoing screening with cell-free DNA (cfDNA), combined first-trimester screening (CFTS), second-trimester serum screening (STSS), and/or prenatal and postnatal cytogenetic testing with the aim to (1) obtain population-based estimates of utilization of prenatal screening and invasive diagnosis, (2) analyze the performance of different prenatal screening strategies, and (3) report the residual risk of any major chromosomal abnormality following a low-risk aneuploidy screening result.

Methods: This was a retrospective study of women residing in the state of Victoria, Australia, who underwent prenatal screening or invasive prenatal diagnosis in 2015. Patient-funded cfDNA referrals from multiple providers were merged with state-wide results for government-subsidized CFTS, STSS and invasive diagnostic procedures.

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Adaptive immunity is based on peptide antigen recognition. Our ability to harness the immune system for therapeutic gain relies on the discovery of the T cell receptor (TCR) genes that selectively target antigens from infections, mutated proteins, and foreign agents. Here we present a method that selectively labels peptide antigen-specific CD8+ T cells using magnetic nanoparticles functionalized with peptide-MHC tetramers, isolates these specific cells within an integrated microfluidic device, and directly amplifies the TCR genes for sequencing.

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Neoantigen-specific T cells are increasingly viewed as important immunotherapy effectors, but physically isolating these rare cell populations is challenging. Here, we describe a sensitive method for the enumeration and isolation of neoantigen-specific CD8+ T cells from small samples of patient tumor or blood. The method relies on magnetic nanoparticles that present neoantigen-loaded major histocompatibility complex (MHC) tetramers at high avidity by barcoded DNA linkers.

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T cell receptor (TCR) ligand discovery is essential for understanding and manipulating immune responses to tumors. We developed a cell-based selection platform for TCR ligand discovery that exploits a membrane transfer phenomenon called trogocytosis. We discovered that T cell membrane proteins are transferred specifically to target cells that present cognate peptide-major histocompatibility complex (MHC) molecules.

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CD8 T cells recognize and eliminate tumors in an antigen-specific manner. Despite progress in characterizing the antitumor T cell repertoire and function, the identification of target antigens remains a challenge. Here we describe the use of chimeric receptors called signaling and antigen-presenting bifunctional receptors (SABRs) in a cell-based platform for T cell receptor (TCR) antigen discovery.

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Tumor-specific T cell receptor (TCR) gene transfer enables specific and potent immune targeting of tumor antigens. Due to the prevalence of the HLA-A2 MHC class I supertype in most human populations, the majority of TCR gene therapy trials targeting public antigens have employed HLA-A2-restricted TCRs, limiting this approach to those patients expressing this allele. For these patients, TCR gene therapy trials have resulted in both tantalizing successes and lethal adverse events, underscoring the need for careful selection of antigenic targets.

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Objective: To utilise image score-based criteria for second-trimester fetal biometry as an educational tool to improve biometry quality.

Methods: Five sonographers regularly performing obstetric ultrasound examinations were recruited for this study. Biometry images were collected from fifteen second-trimester examinations for each sonographer prior to participating in a biometry education session, and another set of biometry images were collected from fifteen second-trimester examinations following the education session.

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HIV controllers (HCs) are individuals who can naturally control HIV infection, partially due to potent HIV-specific CD8+ T cell responses. Here, we examined the hypothesis that superior function of CD8+ T cells from HCs is encoded by their T cell receptors (TCRs). We compared the functional properties of immunodominant HIV-specific TCRs obtained from HLA-B*2705 HCs and chronic progressors (CPs) following expression in primary T cells.

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For adoptive cell transfer (ACT) immunotherapy of tumor-reactive T cells, an effective therapeutic outcome depends upon cell dose, cell expansion in vivo through a minimally differentiated phenotype, long term persistence, and strong cytolytic effector function. An incomplete understanding of the biological coupling between T cell expansion, differentiation, and response to stimulation hinders the co-optimization of these factors. We report on a biophysical investigation of how the short-term kinetics of T cell functional activation, through molecular stimulation and cell-cell interactions, competes with phenotype differentiation.

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The immune system can mount T cell responses against tumors; however, the antigen specificities of tumor-infiltrating lymphocytes (TILs) are not well understood. We used yeast-display libraries of peptide-human leukocyte antigen (pHLA) to screen for antigens of "orphan" T cell receptors (TCRs) expressed on TILs from human colorectal adenocarcinoma. Four TIL-derived TCRs exhibited strong selection for peptides presented in a highly diverse pHLA-A02:01 library.

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Immunotherapies are yielding effective treatments for several previously untreatable cancers. Until recently, vaccines and adoptive cell therapies have been designed to target public tumor antigens common to multiple patients rather than private antigens specific to a single patient. Due to the difficulty of identifying public antigens that are expressed exclusively on tumor cells, these studies have yielded both clinical successes and serious immune-related adverse events.

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Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3TCR-αβ single-positive CD8 or CD4 cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs.

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Peptide-major histocompatibility complex (pMHC) multimers enable the detection, characterization, and isolation of antigen-specific T-cell subsets at the single-cell level via flow cytometry and fluorescence microscopy. These labeling reagents exploit a multivalent scaffold to increase the avidity of individually weak T-cell receptor (TCR)-pMHC interactions. Dextramers are an improvement over the original streptavidin-based tetramer technology because they are more multivalent, improving sensitivity for rare, low-avidity T cells, including self/tumor-reactive clones.

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T cells engineered to express a tumor-specific αβ T cell receptor (TCR) mediate anti-tumor immunity. However, mispairing of the therapeutic αβ chains with endogenous αβ chains reduces therapeutic TCR surface expression and generates self-reactive TCRs. We report a general strategy to prevent TCR mispairing: swapping constant domains between the α and β chains of a therapeutic TCR.

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Background: Web-delivered interventions are a feasible approach to health promotion. However, if a website is poorly designed, difficult to navigate, and has technical bugs, it will not be used as intended. Usability testing prior to evaluating a website's benefits can identify barriers to user engagement and maximize future use.

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Health status and health literacy are interrelated. Previous research suggests that this relationship must be considered when providing services to HIV positive individuals. However, the pathways through which health literacy affects HIV remain unclear.

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Objectives: The purpose of this study was to determine whether measurement of the near-field lateral ventricular diameter can be reliably obtained within a practical time frame during second-trimester obstetric scans by angling the fetal head approximately 30° away from the horizontal image axis such that the posterior aspect of the fetal head lies closer to the transducer.

Methods: Fifty consecutive singleton pregnancies presenting for a routine-second trimester scan were recruited for this study. The far-field lateral ventricular diameter was measured, followed by the near-field lateral ventricular diameter using the proposed technique.

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