Context-dependent environmental associations with endometrial cancer histotype and genotype.

OBJECTIVE: MLH1 loss due to MLH1 methylation, detected during Lynch syndrome screening, is one of the most common molecular changes in endometrial cancer. It is well established that environmental influences such as nutritional state can impact gene methylation, both in the germline and in a tumor. In colorectal cancer and other cancer types, aging is associated with changes in gene methylation. The objective of this study was to determine if there was an association between aging or body mass index on MLH1 methylation in sporadic endometrial cancer. METHODS: A retrospective review of patients with endometrial cancer was performed. Tumors were screened for Lynch syndrome via immunohistochemistry, with MLH1 methylation analysis performed when there was loss of MLH1 expression. Clinical information was abstracted from the medical record. RESULTS: There were 114 patients with mismatch repair deficient tumors associated with MLH1 methylation, and 349 with mismatch repair proficient tumors. Patients with mismatch repair deficient tumors were older than those whose tumors were proficient. Mismatch repair deficient tumors had a higher incidence of lymphatic/vascular space invasion. When stratified by endometrioid grade, associations with body mass index and age became apparent. Patients with endometrioid grades 1 and 2 tumors and somatic mismatch repair deficiency were significantly older, but body mass index was comparable with that of the mismatch repair intact group. For endometrioid grade 3, patient age did not significantly vary between the somatic mismatch repair deficient group and the mismatch repair intact group. In contrast, body mass index was significantly higher in the patients with grade 3 tumors with somatic mismatch repair deficiency. CONCLUSION: The relationship of MLH1 methylated endometrial cancer with age and body mass index is complex and somewhat dependent on tumor grade. As body mass index is modifiable, it is possible that weight loss induces a 'molecular switch' to alter the histologic characteristics of an endometrial cancer.

Mosaic and non-mosaic protocadherin 19 mutation leads to neuronal hyperexcitability in zebrafish.

Epilepsy is one of the most common neurological disorders. The X-linked gene PCDH19 is associated with sporadic and familial epilepsy in humans, typically with early-onset clustering seizures and intellectual disability in females but not in so-called 'carrier' males, suggesting that mosaic PCDH19 expression is required to produce epilepsy. To characterize the role of loss of PCDH19 function in epilepsy, we generated zebrafish with truncating pcdh19 variants. Evaluating zebrafish larvae for electrophysiological abnormalities, we observed hyperexcitability phenotypes in both mosaic and non-mosaic pcdh19+/- and pcdh19-/- mutant larvae. Thus, we demonstrate that the key feature of epilepsy-network hyperexcitability-can be modeled effectively in zebrafish, even though overt spontaneous seizure-like swim patterns were not observed. Further, zebrafish with non-mosaic pcdh19 mutation displayed reduced numbers of inhibitory interneurons suggesting a potential cellular basis for the observed hyperexcitability. Our findings in both mosaic and non-mosaic pcdh19 mutant zebrafish challenge the prevailing theory that mosaicism governs all PCDH19-related phenotypes and point to interneuron-mediated mechanisms underlying these phenotypes.

Trauma-Informed Home Visiting Models in Public Health Nursing: An Evidence-Based Approach.

Traumatic experiences can have significant health effects, particularly when they are experienced during childhood. Structural determinants of health including environmental disasters and limited access to mental health services and affordable housing can contribute additional stress for parents with a personal history of childhood adversity. These factors can directly affect their children, contributing to intergenerational trauma. Pregnant people and families with young children are often referred to public health nursing maternal and child home visiting (HV) programs when there are concerns about historical or evolving childhood trauma. The strict eligibility and participation requirements of existing evidence-based maternal and child HV programs can exclude families that have experienced or are experiencing childhood trauma and its effects and can limit innovation by public health nurses, a hallmark of the field. Therefore, we advocate and describe the implementation of the Trauma Informed Approach in Public Health Nursing (TIA PHN) model, which incorporates a trauma-informed approach into a traditional maternal and child HV program in 3 California counties. TIA PHN, which began enrollment in March 2021, involves public health nurses and community health workers and integrates program evaluations in pursuit of evidence-based status. (Am J Public Health. 2022;112(S3):S298-S305. https://doi.org/10.2105/AJPH.2022.306737).

Biocatalytic Asymmetric Construction of Secondary and Tertiary Fluorides from ß-Fluoro-α-Ketoacids.

Fluorine is a critical element for the design of bioactive compounds, driving advances in selective and sustainable fluorination. However, stereogenic tertiary fluorides pose a synthetic challenge and are thus present in only a few approved drugs (fluticasone, solithromycin, and sofosbuvir). The aldol reaction of fluorinated donors provides an atom-economical approach to asymmetric C-F motifs via C-C bond formation. We report that the type II pyruvate aldolase HpcH and engineered variants perform addition of ß-fluoro-α-ketoacids (including fluoropyruvate, ß-fluoro-α-ketobutyrate, and ß-fluoro-α-ketovalerate) to diverse aldehydes. The reactivity of HpcH towards these fluoro-donors grants access to enantiopure secondary or tertiary fluorides. In addition to representing the first synthesis of tertiary fluorides via biocatalytic carboligation, the afforded products could improve the diversity of fluorinated building blocks and enable the synthesis of fluorinated drug analogs.

Acute kidney injury, stroke and death after cardiopulmonary bypass surgery: the role of perfusion flow and pressure.

INTRODUCTION: Acute kidney injury after cardiopulmonary bypass surgery is associated with morbidity and mortality. This study aims to evaluate the role of low perfusion flow and pressure in the development of cardiopulmonary bypass-associated acute kidney injury, stroke and death, using multicentre registry data. METHODS: We identified patients from the Australian and New Zealand Collaborative Perfusion Registry who underwent coronary artery bypass grafting and/or valvular surgery between 2008 and 2018. Primary predictor variables were the length of time the perfusion flow was <1.6 L/min/m2 and the length of time perfusion pressure was < 50mmHg. The primary outcome was new postoperative acute kidney injury defined by the risk-injury-failure-loss-end stage criteria. Secondary outcomes were stroke and in-hospital death. The influence of perfusion flow and pressure during cardiopulmonary bypass on the primary and secondary outcomes was estimated using separate multivariate models. RESULTS: A total of 16,356 patients were included. The mean age was 66 years and 75% were male. Acute kidney injury was observed in 1,844 patients (11%), stroke in 204 (1.3%) and in-hospital death in 286 (1.8%). Neither the duration of the time spent for perfusion flow (<1.6 L/minute/m2) nor the duration of the time spent for perfusion pressure (<50 mmHg) was associated with postoperative acute kidney injury, stroke or death in adjusted models. CONCLUSIONS: Neither low perfusion pressure nor low perfusion flow during cardiopulmonary bypass were predictive of postoperative acute kidney injury, stroke or death.

Improving body functions through participation in community activities among young people with physical disabilities.

AIM: To examine the impact of engagement in a self-chosen community-based activity on three relevant body functions (motor, cognitive, and affective) as well as on the performance of the selected activity. METHOD: An individual-based interrupted time series design with multiple baselines was used. Seven young people (four males, three females) aged 15 to 25 years (median 18y; interquartile range 17-20y) with physical disabilities participated in an 8-week community activity of choice (e.g. swimming, playing piano). Change in three relevant body functions, underpinning the specific chosen activity, including motor (e.g. Functional Reach Test, Trunk Impairment Scale, dynamometers), cognitive and affective (Behavior Assessment System for Children), as well as activity performance (Canadian Occupational Performance Measure) were measured repeatedly, providing individual outcome trajectories. Linear and mixed-effects models were used. RESULTS: Significant improvements in at least one aspect of motor function (6 out of 6), cognition (3 out of 3), affect (5 out of 7), and performance (7 out of 7) were observed. Specifically, the intervention had a moderate to large effect on hyperactivity (1.45, 95% confidence interval [CI] 1.0-1.9) with a smaller effect on anxiety (0.21, 95% CI 0.10-0.32) and inadequacy (0.21, 95% CI 0.02-0.39). Concurrently, a notable effect size for activity performance (4.61, 95% CI 0.76-8.46) was observed. Average change across motor outcomes was substantial (3.7 SDs from baseline), yet non-significant. INTERPERTATION: Findings provide initial evidence of the benefits resulting from participation-based interventions, emphasizing the merit of meaningful 'real-life' young people-engaging therapy. WHAT THIS PAPER ADDS: Participation-based interventions can impact body-function level outcomes. Significant improvements in the performance of chosen activities were observed. Significant improvements were also seen in cognitive and affective body functions. Improvements in motor-related outcomes were substantial but not statistically significant.

Trauma informed public health nursing visits to parents and children.

Adverse Childhood Experiences (ACEs) research has demonstrated a strong correlation between a traumatic childhood and poor health and social status in adulthood. Maternal/child Public Health Nursing (PHN) home visiting teams frequently encounter families experiencing trauma, thus offering a unique opportunity to assist parents in recognizing the potential harm such stress may have for their child. The Sonoma County Field Nursing team developed a trauma-informed model utilizing ACEs education in a self-reflective approach with parents to increase family resilience and reduce the risk for future childhood trauma. This paper presents the supporting research used to develop the trauma-informed approach and describes the execution of the model by the Sonoma County Field Nursing team.

SEPT8 modulates ß-amyloidogenic processing of APP by affecting the sorting and accumulation of BACE1.

Dysfunction and loss of synapses are early pathogenic events in Alzheimer's disease. A central step in the generation of toxic amyloid-ß (Aß) peptides is the cleavage of amyloid precursor protein (APP) by ß-site APP-cleaving enzyme (BACE1). Here, we have elucidated whether downregulation of septin (SEPT) protein family members, which are implicated in synaptic plasticity and vesicular trafficking, affects APP processing and Aß generation. SEPT8 was found to reduce soluble APPß and Aß levels in neuronal cells through a post-translational mechanism leading to decreased levels of BACE1 protein. In the human temporal cortex, we identified alterations in the expression of specific SEPT8 transcript variants in a manner that correlated with Alzheimer's-disease-related neurofibrillary pathology. These changes were associated with altered ß-secretase activity. We also discovered that the overexpression of a specific Alzheimer's-disease-associated SEPT8 transcript variant increased the levels of BACE1 and Aß peptides in neuronal cells. These changes were related to an increased half-life of BACE1 and the localization of BACE1 in recycling endosomes. These data suggest that SEPT8 modulates ß-amyloidogenic processing of APP through a mechanism affecting the intracellular sorting and accumulation of BACE1.

The histone methyltransferase SETDB1 is recurrently amplified in melanoma and accelerates its onset.

The most common mutation in human melanoma, BRAF(V600E), activates the serine/threonine kinase BRAF and causes excessive activity in the mitogen-activated protein kinase pathway. BRAF(V600E) mutations are also present in benign melanocytic naevi, highlighting the importance of additional genetic alterations in the genesis of malignant tumours. Such changes include recurrent copy number variations that result in the amplification of oncogenes. For certain amplifications, the large number of genes in the interval has precluded an understanding of the cooperating oncogenic events. Here we have used a zebrafish melanoma model to test genes in a recurrently amplified region of chromosome 1 for the ability to cooperate with BRAF(V600E) and accelerate melanoma. SETDB1, an enzyme that methylates histone H3 on lysine 9 (H3K9), was found to accelerate melanoma formation significantly in zebrafish. Chromatin immunoprecipitation coupled with massively parallel DNA sequencing and gene expression analyses uncovered genes, including HOX genes, that are transcriptionally dysregulated in response to increased levels of SETDB1. Our studies establish SETDB1 as an oncogene in melanoma and underscore the role of chromatin factors in regulating tumorigenesis.

Young people have their say: What makes a youth-friendly general practice?

BACKGROUND: The health of young people can be considered an indicator of the health of Australia's future population. To improve access to healthcare, the perspectives of adolescents on the design and delivery of services need to be championed. The objective of this study was to identify what young people in north-west Tasmania value when seeking healthcare at general practices. METHODS: The study was conducted at a single high school in rural Tasmania. Students aged 16-18 years were invited to participate in an electronic survey seeking their views and preferences for presenting to their general practitioner (GP). RESULTS: One hundred and fifty-five students, with a mean age of 17 years, were surveyed. GPs were the usual healthcare providers for 98.4% of participants, and 86% stated that they would like to discuss mental health, substance use and sexual health with their GP. DISCUSSION: GPs can improve access to care for young people through good communications skills and treating young people as young adults.

Parkinson's Disease and Driving Cessation: a Journey Influenced by Anxiety.

OBJECTIVES: In addition to the motor and cognitive symptoms that people with Parkinson's disease (PD) typically experience, psychiatric symptoms such as anxiety are also commonly experienced by people with PD. The overall purpose of the current study was to explore driving and driving cessation for people with PD and their families. METHODS: A descriptive phenomenological approach was employed using semi-structured interviews and 34 interviews were conducted overall (22 participants with PD and 12 family members). RESULTS: Experiences of anxiety and worry that had an impact on driving and driving cessation arose from the data, and this article specifically captured the lived experience of anxiety with driving and driving cessation for people with PD and their families. CONCLUSIONS: Findings reveal that the experience of anxiety while driving, as well as anticipatory anxiety and/or worry related to driving cessation, affect the driving experiences and wellbeing of people with PD. CLINICAL IMPLICATIONS: Implications of the study findings are outlined and aim to provide information about the needs to enable future clinical directions to be developed.

The Benefits and Challenges of Preconsent in a Multisite, Pediatric Sickle Cell Intervention Trial.

Enrollment of patients in sickle cell intervention trials has been challenging due to difficulty in obtaining consent from a legal guardian and lack of collaboration between emergency medicine and hematology. We utilized education and preconsent in a pediatric multisite sickle cell intervention trial to overcome these challenges. Overall, 48 patients were enrolled after being preconsented. Variable Institutional Review Board policies related to preconsent validity and its allowable duration decreased the advantages of preconsent at some sites. The utility of preconsent for future intervention trials largely depends on local Institutional Review Board policies. Preeducation may also benefit the consent process, regardless of site differences.

Improving the participation of youth with physical disabilities in community activities: An interrupted time series design.

BACKGROUND/AIM: Youth with physical disabilities experience restrictions to participation in community-based leisure activities; however, there is little evidence about how to improve their involvement. This study examined whether an intervention to remove environmental barriers and develop strategies using a coaching approach improved youth participation in leisure activities. METHODS: An Interrupted Time Series design was employed, where replication of the intervention effect was examined across individualised participation goals and across participants. Six adolescents with a physical disability participated in a 12-week intervention. An occupational therapist worked with each youth and his/her family to set three leisure goals based on problems identified using the Canadian Occupational Performance Measure (COPM). A coaching approach was used to collaboratively identify and implement strategies to remove environmental barriers. Interventions for each goal were introduced at different time points. Outcomes were evaluated using the COPM. RESULTS: Improvements in COPM performance scores were clinically significant for 83% of the identified activities; an average change of 4.5 points in the performance scale (SD = 1.95) was observed. Statistical analysis using the celeration line demonstrated that the proportion of data points falling above the line increased in the intervention phase for 94% of the activities, indicating a significant treatment effect. CONCLUSIONS: This study is the first to examine an intervention aimed at increasing leisure participation by changing only the environment. The results indicate that environment-focussed interventions are feasible and effective in promoting youth participation. Such findings can inform the design of a larger study and guide occupational therapy practice.

Age-related changes in perception of movement in driving scenes.

PURPOSE: Age-related changes in motion sensitivity have been found to relate to reductions in various indices of driving performance and safety. The aim of this study was to investigate the basis of this relationship in terms of determining which aspects of motion perception are most relevant to driving. METHODS: Participants included 61 regular drivers (age range 22-87 years). Visual performance was measured binocularly. Measures included visual acuity, contrast sensitivity and motion sensitivity assessed using four different approaches: (1) threshold minimum drift rate for a drifting Gabor patch, (2) Dmin from a random dot display, (3) threshold coherence from a random dot display, and (4) threshold drift rate for a second-order (contrast modulated) sinusoidal grating. Participants then completed the Hazard Perception Test (HPT) in which they were required to identify moving hazards in videos of real driving scenes, and also a Direction of Heading task (DOH) in which they identified deviations from normal lane keeping in brief videos of driving filmed from the interior of a vehicle. RESULTS: In bivariate correlation analyses, all motion sensitivity measures significantly declined with age. Motion coherence thresholds, and minimum drift rate threshold for the first-order stimulus (Gabor patch) both significantly predicted HPT performance even after controlling for age, visual acuity and contrast sensitivity. Bootstrap mediation analysis showed that individual differences in DOH accuracy partly explained these relationships, where those individuals with poorer motion sensitivity on the coherence and Gabor tests showed decreased ability to perceive deviations in motion in the driving videos, which related in turn to their ability to detect the moving hazards. CONCLUSIONS: The ability to detect subtle movements in the driving environment (as determined by the DOH task) may be an important contributor to effective hazard perception, and is associated with age, and an individuals' performance on tests of motion sensitivity. The locus of the processing deficits appears to lie in first-order, rather than second-order motion pathways.

Zebrafish models of candidate human epilepsy-associated genes provide evidence of hyperexcitability.

Hundreds of novel candidate human epilepsy-associated genes have been identified thanks to advancements in next-generation sequencing and large genome-wide association studies, but establishing genetic etiology requires functional validation. We generated a list of >2200 candidate epilepsy-associated genes, of which 81 were determined suitable for the generation of loss-of-function zebrafish models via CRISPR/Cas9 gene editing. Of those 81 crispants, 48 were successfully established as stable mutant lines and assessed for seizure-like swim patterns in a primary F2 screen. Evidence of seizure-like behavior was present in 5 (arfgef1, kcnd2, kcnv1, ubr5, wnt8b) of the 48 mutant lines assessed. Further characterization of those 5 lines provided evidence for epileptiform activity via electrophysiology in kcnd2 and wnt8b mutants. Additionally, arfgef1 and wnt8b mutants showed a decrease in the number of inhibitory interneurons in the optic tectum of larval animals. Furthermore, RNAseq revealed convergent transcriptional abnormalities between mutant lines, consistent with their developmental defects and hyperexcitable phenotypes. These zebrafish models provide strongest experimental evidence supporting the role of ARFGEF1, KCND2, and WNT8B in human epilepsy and further demonstrate the utility of this model system for evaluating candidate human epilepsy genes.

CXCR3-dependent recruitment and CCR6-mediated positioning of Th-17 cells in the inflamed liver.

BACKGROUND & AIMS: IL-17 secreting CD4 (Th17) and CD8 (Tc17) T cells have been implicated in immune-mediated liver diseases, but the molecular basis for their recruitment and positioning within the liver is unknown. METHODS: The phenotype and migratory behaviour of human liver-derived Th17 and Tc17 cells were investigated by flow cytometry and chemotaxis and flow-based adhesion assays. The recruitment of murine Th17 cells to the liver was studied in vivo using intra-vital microscopy. RESULTS: IL-17(+) T cells comprised 1-3% of the T cell infiltrate in inflammatory liver diseases and included both CD4 (Th17) and CD8 (Tc17) cells. They expressed RORC and the IL-23 receptor and included subsets that secreted IL-22 and interferon-γ. Th17 and Tc17 cells expressed high levels of CXCR3 and CCR6, Tc17 cells also expressed CXCR6. Binding to human sinusoidal endothelium from flow was dependent on ß1 and ß2 integrins, CXCR3, and, in the case of Th17 cells, VAP-1. Th17 recruitment via sinusoids in mice with liver inflammation was reduced by treatment with antibodies against CXCR3 ligands, confirming the role of CXCR3 in Th17 recruitment in vivo. In human liver, IL-17(+) cells were detected in portal infiltrates close to inflamed bile ducts expressing the CCR6 ligand CCL20. Cytokine-treated human cholangiocytes secreted CCL20 and induced CCR6-dependent migration of Th17 cells suggesting that local cholangiocyte chemokine secretion localises Th17 cells to bile ducts. CONCLUSIONS: CXCR3 promotes recruitment of Th17 cells from the blood into the liver in both human and murine liver injury. Their subsequent positioning near bile ducts is dependent on cholangiocyte-secreted CCL20.

Maculopathy Masquerading as Migraine.

We describe a case of a 23-year-old Caucasian woman with a background history of migraines who presented with bilateral paracentral scotomata. The ophthalmoscopy and MRI head were originally thought to be normal, and the scotomata were attributed to be of migrainous origin: a persistent negative aura. However, persistence of her symptoms prompted further specialist review 10 months later, at which time subtle bilateral perifoveal changes were noted, which had been apparent but overlooked at the initial assessment. Near-infrared reflectance imaging enabled better visualization of the lesions, which were apparent prior to any abnormalities on clinical examination. Spectral-domain optical coherence tomography revealed the early findings of hyperreflectivity in the outer nuclear and outer plexiform layers characteristic of acute macular neuroretinopathy. Our case aims to emphasize the importance of scrutinising ancillary tests of the macula in patients presenting with scotomata or atypical migraine symptoms, and to caution clinicians against diagnosing migraine with persistent negative aura without these investigations.

Scaling Up Behavioral Skills Training: Effectiveness of Large-Scale and Multiskill Trainings.

We used behavioral skills training (BST) to teach multiple skills to 2 cohorts of 18 participants. BST consisted of the standard 4 components: (a) didactic instruction, (b) modeling, (c) role-play, and (d) feedback, modified to be delivered in a large-group format. All components were provided by 1 trainer, simultaneously to all participants, with peers delivering feedback during role-plays. Across 4 targeted skills (e.g., discrete-trial teaching), the average performance of Cohort 1 improved from less than 60% correct implementation in baseline to a performance of between 85% and 100% correct, across participants, following BST. We used social validity data collected from Cohort 1 to modify the length of instruction across skills for Cohort 2. BST was similarly effective for Cohort 2, with a decrease in the additional training required for trainees to demonstrate the skill in a novel role-play scenario or with a client. Implications for effectively scaling up BST are discussed.

A randomized controlled trial of exercise on augmenting the effects of cognitive remediation in persons with severe mental illness.

BACKGROUND: Preliminary evidence suggests that aerobic exercise may augment the effects of cognitive remediation on improving cognitive functioning in severe mental illness. It has also been hypothesized that increases in cognitive functioning associated with adding exercise are mediated by increases in brain derived neurotrophic factor (BDNF). However, rigorous controlled trials are lacking. METHODS: A randomized controlled trial was conducted to explore whether adding a 30-h aerobic exercise program over 10 weeks to an equally intensive cognitive remediation program (CR + E) improved cognitive functioning more than cognitive remediation alone (CR-Only). Thirty-four participants with schizophrenia or bipolar disorder were randomly assigned to CR + E or CR-Only, and cognitive functioning was assessed at baseline and post-treatment. Total and mature BDNF were measured in blood serum at baseline, Week-5 pre- and post-exercise, and Week-10 pre- and post-exercise. RESULTS: Participants in both conditions had high levels of engagement in the interventions and improved significantly in cognitive functioning, but did not differ in amount of cognitive change. The groups also did not differ in changes in BDNF from pre-to post-exercise at Weeks 5 or 10, nor in resting BDNF levels. Exploratory analyses indicated that higher body mass index (BMI) significantly predicted attenuated improvement in cognitive functioning for both groups. DISCUSSION: Exercise did not augment the effects of cognitive remediation in persons with severe mental illness, possibly because the cognitive remediation program resulted in strong gains in cognitive functioning. Moderate aerobic exercise does not appear to reliably increase BDNF levels in persons with severe mental illness. CLINICALTRIALS. GOV IDENTIFIER: NCT02326389.

Gut homing receptors on CD8 T cells are retinoic acid dependent and not maintained by liver dendritic or stellate cells.

BACKGROUND & AIMS: Lymphocytes primed by intestinal dendritic cells (DC) express the gut-homing receptors CCR9 and alpha4beta7, which recognize CCL25 and mucosal addressin cell-adhesion molecule-1 in the intestine promoting the development of regional immunity. In mice, imprinting of CCR9 and alpha4beta7 is dependent on retinoic acid during T-cell activation. Tissue specificity is lost in primary sclerosing cholangitis (PSC), an extraintestinal manifestation of inflammatory bowel disease, when ectopic expression of mucosal addressin cell-adhesion molecule-1 and CCL25 in the liver promotes recruitment of CCR9+alpha4beta7+ T cells to the liver. We investigated the processes that control enterohepatic T-cell migration and whether the ability to imprint CCR9 and alpha4beta7 is restricted to intestinal DCs or can under some circumstances be acquired by hepatic DCs in diseases such as PSC. METHODS: Human and murine DCs from gut, liver, or portal lymph nodes and hepatic stellate cells were used to activate CD8 T cells. Imprinting of CCR9 and alpha4beta7 and functional migration responses were determined. Crossover activation protocols assessed plasticity of gut homing. RESULTS: Activation by gut DCs imprinted high levels of functional CCR9 and alpha4beta7 on naïve CD8 T cells, whereas hepatic DCs and stellate cells proved inferior. Imprinting was RA dependent and demonstrated plasticity. CONCLUSIONS: Imprinting and plasticity of gut-homing human CD8 T cells requires primary activation or reactivation by gut DCs and is retinoic acid dependent. The inability of liver DCs to imprint gut tropism implies that alpha4beta7+CCR9+ T cell that infiltrate the liver in PSC are primed in the gut.