Selective IL-27 production by intestinal regulatory T cells permits gut-specific regulation of TH17 cell immunity.

Regulatory T cells (Treg cells) are instrumental in establishing immunological tolerance. However, the precise effector mechanisms by which Treg cells control a specific type of immune response in a given tissue remains unresolved. By simultaneously studying Treg cells from different tissue origins under systemic autoimmunity, in the present study we show that interleukin (IL)-27 is specifically produced by intestinal Treg cells to regulate helper T17 cell (TH17 cell) immunity. Selectively increased intestinal TH17 cell responses in mice with Treg cell-specific IL-27 ablation led to exacerbated intestinal inflammation and colitis-associated cancer, but also helped protect against enteric bacterial infection. Furthermore, single-cell transcriptomic analysis has identified a CD83+CD62Llo Treg cell subset that is distinct from previously characterized intestinal Treg cell populations as the main IL-27 producers. Collectively, our study uncovers a new Treg cell suppression mechanism crucial for controlling a specific type of immune response in a particular tissue and provides further mechanistic insights into tissue-specific Treg cell-mediated immune regulation.

Small intestine and colon tissue-resident memory CD8+ T cells exhibit molecular heterogeneity and differential dependence on Eomes.

Tissue-resident memory CD8+ T (TRM) cells are a subset of memory T cells that play a critical role in limiting early pathogen spread and controlling infection. TRM cells exhibit differences across tissues, but their potential heterogeneity among distinct anatomic compartments within the small intestine and colon has not been well recognized. Here, by analyzing TRM cells from the lamina propria and epithelial compartments of the small intestine and colon, we showed that intestinal TRM cells exhibited distinctive patterns of cytokine and granzyme expression along with substantial transcriptional, epigenetic, and functional heterogeneity. The T-box transcription factor Eomes, which represses TRM cell formation in some tissues, exhibited unexpected context-specific regulatory roles in supporting the maintenance of established TRM cells in the small intestine, but not in the colon. Taken together, these data provide previously unappreciated insights into the heterogeneity and differential requirements for the formation vs. maintenance of intestinal TRM cells.

Tocilizumab for the treatment of chronic antibody mediated rejection in kidney transplant recipients.

BACKGROUND: Chronic active antibody-mediated rejection (CAAMR) constitutes a dominant form of late allograft failure. Several treatment strategies directed at CAAMR have been attempted but proven ineffective at delaying kidney function decline or reducing donor-specific antibodies (DSA). We describe our single-center experience using tocilizumab in patients with CAAMR. METHODS: This is a retrospective analysis using electronic medical records. 38 kidney transplant recipients at Columbia University Irving Medical Center who had been prescribed tocilizumab and followed for at least 3 months between August 2013 through December 2019 were included. RESULTS: Tocilizumab use was associated with a decrease in the rate of estimated glomerular filtration rate (eGFR) decline in the 6 months following treatment initiation as compared to the 3 months before tocilizumab was initiated (difference between slopes before and after initiation of treatment = 2.6 mL/min/1.73 m2 (SE = .8, p = .002) per month for up to 6 months following Tocilizumab initiation). Allograft biopsies showed significant improvement in interstitial inflammation scores (score 1(0,1) to 0 (0,1), p = .03) while other histologic scores remained stable. There was no significant change in proteinuria or DSA titers post-treatment with tocilizumab. CONCLUSIONS: Treatment of CAAMR with tocilizumab was associated with a decrease in the rate of eGFR decline and a reduction in interstitial inflammation scores in patients with CAAMR.

Bioanalytical challenges and strategies for accurately measuring acyl glucuronide metabolites in biological fluids.

Bioanalysis of unstable compounds such as acyl glucuronide metabolites represents a great analytical challenge owing to poor analyte stability in biological matrices. The primary goal for bioanalytical assay development is to minimize the breakdown of acyl glucuronide metabolite into its parent aglycone during sample collection, transportation, storage and analysis. Samples need to be stabilized ex vivo immediately after sample collection to minimize potential breakdown and thus to ensure accurate concentration measurement of both acyl glucuronide metabolite and its parent aglycone. In this review paper, formation of acyl glucuronide metabolites, the importance of establishing acyl glucuronide exposure measurement and safety coverage, optimization of sample pretreatment to stabilize the acyl glucuronide metabolites, current analytical strategy of assaying them as well as considerations for regulatory filings are discussed. It is important to identify acyl glucuronide metabolites that are capable of undergoing hydrolysis and pH-dependent intra-molecular migration as well as covalently binding to plasma and tissue proteins which can cause toxicity in vivo in the early stages of drug development. Carefully planning analytical experiments, identifying structures of acyl glucuronides and monitoring their concentrations in early drug development can help assess the risks associated with their exposures and potentially predict their concentrations in human circulation.

Analysis of dendritic cells and ischemia-reperfusion changes in postimplantation renal allograft biopsies may serve as predictors of subsequent rejection episodes.

Ischemia-reperfusion injury increases allograft immunogenicity and enhances myeloid dendritic cell maturation and trafficking to recipient's secondary lymphoid tissue. Here, we used postreperfusion biopsies from patients who received kidney allografts from deceased donors between 2006 and 2009 to assess the impact of ischemia-reperfusion damage and myeloid dendritic cell density on subsequent allograft rejection episodes. Histologic changes of severe ischemia-reperfusion damage in postreperfusion biopsies were found to be associated with subsequent rejection episodes and suboptimal allograft survival. Using BDCA-1 as a marker of myeloid dendritic cells, postreperfusion biopsies from deceased donors had lower dendritic cell density compared to postreperfusion biopsies from living donors or normal controls. This suggests a rapid emigration of donor dendritic cells out of the allograft. In our cohort, low dendritic cell density was associated with a subsequent increase in rejection episodes. However, it appears that the donor's cause of death also influenced dendritic cell density. Therefore, we assessed the additive impact of severe ischemia-reperfusion changes and low dendritic cell density on subsequent rejection. The aforementioned combination was a powerful and independent predictor of allograft rejection. Thus, our data highlight the prognostic value of histopathologic changes associated with ischemia-reperfusion in postreperfusion biopsies and suggest a rapid posttransplant emigration of myeloid dendritic cells out of the allograft to enhance alloimmunity. These findings may provide a rationale for minimizing ischemia-reperfusion injury and therapeutic targeting of donor-derived dendritic cells to promote rejection-free allograft survival.

Outcomes for potential kidney transplant recipients offered public health service increased risk kidneys: A single-center experience.

BACKGROUND: Discard rate of Public Health Service Increased Risk (PHS-IR) organs is high despite the absence of worse kidney transplant outcomes. METHODS: We conducted a retrospective, single-center study of PHS-IR kidney offers made to kidney transplant-only potential recipients from 6/2004 to 5/2015. Overall mortality and transplant outcomes between potential recipients were stratified by response to PHS-IR kidney offers. Cox regression and Kaplan-Meier analyses of mortality and allograft failure were performed. RESULTS: A total of 2423 potential recipients were offered a PHS-IR kidney, with 1502 transplanted, with or without a PHS-IR kidney. Predictors of accepting a PHS-IR kidney included higher Estimated Post Transplant Survival (EPTS) score, prior kidney transplant, and lower educational achievement on multivariable analysis (P = 0.025, P = 0.004, P = 0.023). A positive response to a PHS-IR kidney was associated with lower risk of mortality (3.63% vs 11.6%; aHR 0.467, P = 0.0008). PHS-IR kidney recipients had decreased risk of allograft loss compared to non-PHS-IR recipients (P = 0.007), though mortality outcomes were not significantly different based on PHS-IR status (P = 0.38). No transmission of HIV, HBV, or HCV occurred from PHS-IR kidney donors in this cohort. CONCLUSIONS: Efforts must be made to increase awareness of the beneficial outcomes of PHS-IR organs to maximize appropriate donor allocation.

Responsiveness to Vedolizumab Therapy in Ulcerative Colitis is Associated With Alterations in Immune Cell-Cell Communications.

BACKGROUND: Ulcerative colitis (UC) and Crohn's disease are 2 types of inflammatory bowel disease (IBD), a group of chronic digestive disorders caused by aberrant immune responses to intestinal microbes. Although changes in the composition of immune cell subsets in the context of IBD have been previously described, the interactions and communication among cells are less well understood. Moreover, the precise mechanisms of action underlying many biologic therapies, including the anti-α4ß7 integrin antagonist vedolizumab, remain incompletely understood. Our study aimed to explore possible additional mechanisms through which vedolizumab acts. METHODS: We performed cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) on peripheral blood and colon immune cells derived from patients with ulcerative colitis treated with the anti-α4ß7 integrin antagonist vedolizumab. We applied a previously published computational approach, NicheNet, to predict immune cell-cell interactions, revealing putative ligand-receptor pairs and key transcriptional changes downstream of these cell-cell communications (CCC). RESULTS: We observed decreased proportions of T helper 17 (TH17) cells in UC patients who responded to vedolizumab and therefore focused the study on identifying cell-cell communications and signals of TH17 cells with other immune cells. For example, we observed that colon TH17 cells from vedolizumab nonresponders were predicted to have a greater degree of interactions with classical monocytes compared with responders, whereas colon TH17 cells from vedolizumab responders exhibited more interactions with myeloid dendritic cells compared with nonresponders. CONCLUSIONS: Overall, our results indicate that efforts to elucidate cell-cell communications among immune and nonimmune cell types may increase the mechanistic understanding of current and investigational therapies for IBD.

Compared to ulcerative patients unresponsive to vedolizumab, immune cell networks of ulcerative colitis patients responsive to vedolizumab have decreased proportion of TH17 and less pro-inflammatory signaling in the gut. Decreased pro-TH17 and interleukin (IL)-1 signaling from classical monocytes and innate immunocytes may mediate this phenotype.

Identification of CD8 + T-Cell-Immune Cell Communications in Ileal Crohn's Disease.

INTRODUCTION: Crohn's disease (CD) is a major subtype of inflammatory bowel disease (IBD), a spectrum of chronic intestinal disorders caused by dysregulated immune responses to gut microbiota. Although transcriptional and functional changes in a number of immune cell types have been implicated in the pathogenesis of IBD, the cellular interactions and signals that drive these changes have been less well-studied. METHODS: We performed Cellular Indexing of Transcriptomes and Epitopes by sequencing on peripheral blood, colon, and ileal immune cells derived from healthy subjects and patients with CD. We applied a previously published computational approach, NicheNet, to predict immune cell types interacting with CD8 + T-cell subsets, revealing putative ligand-receptor pairs and key transcriptional changes downstream of these cell-cell communications. RESULTS: As a number of recent studies have revealed a potential role for CD8 + T-cell subsets in the pathogenesis of IBD, we focused our analyses on identifying the interactions of CD8 + T-cell subsets with other immune cells in the intestinal tissue microenvironment. We identified ligands and signaling pathways that have implicated in IBD, such as interleukin-1ß, supporting the validity of the approach, along with unexpected ligands, such as granzyme B, which may play previously unappreciated roles in IBD. DISCUSSION: Overall, these findings suggest that future efforts focused on elucidating cell-cell communications among immune and nonimmune cell types may further our understanding of IBD pathogenesis.

Selective IL-27 production by intestinal regulatory T cells permits gut-specific regulation of Th17 immunity.

Regulatory T (Treg) cells are instrumental in establishing immunological tolerance. However, the precise effector mechanisms by which Treg cells control a specific type of immune response in a given tissue remains unresolved. By simultaneously studying Treg cells from different tissue origins under systemic autoimmunity, here we show that IL-27 is specifically produced by intestinal Treg cells to regulate Th17 immunity. Selectively increased intestinal Th17 responses in mice with Treg cell-specific IL-27 ablation led to exacerbated intestinal inflammation and colitis-associated cancer, but also helped protect against enteric bacterial infection. Furthermore, single-cell transcriptomic analysis has identified a CD83+TCF1+ Treg cell subset that is distinct from previously characterized intestinal Treg cell populations as the main IL-27 producers. Collectively, our study uncovers a novel Treg cell suppression mechanism crucial for controlling a specific type of immune response in a particular tissue, and provides further mechanistic insights into tissue-specific Treg cell-mediated immune regulation.

Diversity and inclusion in the bioanalytical industry: an interview with Shefali R Patel.

Shefali R Patel speaks to Sankeetha Nadarajah, Commissioning Editor.

You Cannot Hit Snooze on OSA: Sequelae of Pediatric Obstructive Sleep Apnea.

Pediatric obstructive sleep apnea (OSA) has been shown to not only affect the quality of sleep, but also overall health in general. Untreated or inadequately treated OSA can lead to long-term sequelae involving cardiovascular, endothelial, metabolic, endocrine, neurocognitive, and psychological consequences. The physiological effects of pediatric OSA eventually become pathological. As the complex effects of pediatric OSA are discovered, they must be identified early so that healthcare providers can be better equipped to treat and even prevent them. Ultimately, adequate management of OSA improves overall quality of life.

A qualitative analysis of people's experiences with weight-based discrimination.

OBJECTIVE: The aim of this study was to describe people's day-to-day experiences with weight-based discrimination and to distill themes that shed new light on this phenomenon. DESIGN: A qualitative study was conducted in 2019 using a purposive sampling strategy. A racially and ethnically diverse sample of 32 U.S. adult men and women with a body mass index ≥30 kg/m2 completed a semi-structured interview. RESULTS: Primary types of interpersonal weight-based discrimination included offensive comments, negative assumptions, social rejection, and unwanted attention or bullying. Participants also encountered environmental sources of weight bias such as inadequate seating in public venues. Three higher order themes that cut across people's experiences with weight-based discrimination were identified: 1) the often-ambiguous nature of weight-based discrimination; 2) intersections between body weight and other social identities; and 3) the role of social comparison processes. CONCLUSION: Findings provide a detailed portrait of people's everyday experiences with weight-based discrimination. These experiences often reflected widely held negative stereotypes about people with higher body weight and conveyed the socially devalued status of higher-weight individuals in society. Findings have important implications for future research and interventions aimed at reducing the harmful effects of weight-based discrimination on health and emotional wellbeing.

Niraparib Shows Superior Tissue Distribution and Efficacy in a Prostate Cancer Bone Metastasis Model Compared with Other PARP Inhibitors.

Patients with prostate cancer whose tumors bear deleterious mutations in DNA-repair pathways often respond to PARP inhibitors. Studies were conducted to compare the activity of several PARP inhibitors in vitro and their tissue exposure and in vivo efficacy in mice bearing PC-3M-luc-C6 prostate tumors grown subcutaneously or in bone. Niraparib, olaparib, rucaparib, and talazoparib were compared in proliferation assays, using several prostate tumor cell lines and in a cell-free PARP-trapping assay. PC-3M-luc-C6 cells were approximately 12- to 20-fold more sensitive to PARP inhibition than other prostate tumor lines, suggesting that these cells bear a DNA damage repair defect. The tissue exposure and efficacy of these PARP inhibitors were evaluated in vivo in PC-3M-luc-C6 subcutaneous and bone metastasis tumor models. A steady-state pharmacokinetic study in PC-3M-luc-C6 tumor-bearing mice showed that all of the PARP inhibitors had favorable subcutaneous tumor exposure, but niraparib was differentiated by superior bone marrow exposure compared with the other drugs. In a PC-3M-luc-C6 subcutaneous tumor efficacy study, niraparib, olaparib, and talazoparib inhibited tumor growth and increased survival to a similar degree. In contrast, in the PC-3M-luc-C6 bone metastasis model, niraparib showed the most potent inhibition of bone tumor growth compared with the other therapies (67% vs. 40%-45% on day 17), and the best survival improvement over vehicle control [hazard ratio (HR), 0.28 vs. HR, 0.46-0.59] and over other therapies (HR, 1.68-2.16). These results show that niraparib has superior bone marrow exposure and greater inhibition of tumor growth in bone, compared with olaparib, rucaparib, and talazoparib.

RORγt phosphorylation protects against T cell-mediated inflammation.

RAR-related orphan receptor-γ (RORγt) is an essential transcription factor for thymic T cell development, secondary lymphoid tissue organogenesis, and peripheral immune cell differentiation. Serine 182 phosphorylation is a major post-translational modification (PTM) on RORγt. However, the in vivo contribution of this PTM in health and disease settings is unclear. We report that this PTM is not involved in thymic T cell development and effector T cell differentiation. Instead, it is a critical regulator of inflammation downstream of IL-1ß signaling and extracellular signal regulated kinases (ERKs) activation. ERKs phosphorylation of serine 182 on RORγt serves to simultaneously restrict Th17 hyperactivation and promote anti-inflammatory cytokine IL-10 production in RORγt+ Treg cells. Phospho-null RORγtS182A knockin mice experience exacerbated inflammation in models of colitis and experimental autoimmune encephalomyelitis (EAE). In summary, the IL-1ß-ERK-RORγtS182 circuit protects against T cell-mediated inflammation and provides potential therapeutic targets to combat autoimmune diseases.

Leveraging patient-centric sampling for clinical drug development and decentralized clinical trials: Promise to reality.

Advances in the technologies to enable patient-centric sampling (PCS) have the potential to improve blood sample collection by enabling clinical trial participants to collect samples via self-collection or with the help of a caregiver in their home. Typically, blood samples to assess pharmacokinetics and pharmacodynamics of a drug during clinical development are collected at a clinical site via venous blood draw. In this position paper by the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ), the potential value PCS can bring to patients, to the clinical datasets generated, and to clinical trial sponsors is discussed, along with considerations for program decision making, bioanalytical feasibility, operations, and regulatory implications. With an understanding of the value of PCS and considerations when implementing during clinical drug development, we can bring the promise of PCS closer to reality and enable decentralized clinical trials.

Home Care Delivery and Remote Patient Monitoring of Kidney Transplant Recipients During COVID-19 Pandemic.

Telehealth plays a critical role in the response of healthcare organizations during the COVID-19 pandemic. While telemedicine offers a real-time patient-provider encounter, the inability to obtain vital signs during virtual visits is a potential limitation. Remote patient monitoring (RPM) uses portable devices in the patient's home to collect and electronically transmit physiological data to clinicians. Two kidney transplant recipients were enrolled in RPM in their immediate post-transplant period. Real-time monitoring of their physiological data at home through the RPM in combination with the ability to titrate medications resulted in normalization of the blood pressure and blood glucose measurements by six weeks. Our initial experience demonstrates that RPM is feasible and effective in the post-transplant period and can expand care opportunities on the remote care model. This is more relevant than ever as remote monitoring can facilitate the care of COVID-19-positive transplant patients who require close monitoring while isolated at home.

Clinical Features of Mycetoma and the Appropriate Treatment Options.

Mycetoma is a chronic, suppurative and debilitating granulomatous infection seen mainly in tropical and subtropical areas and is now declared as a neglected tropical disease by the World Health Organization. The clinical diagnosis is usually characterized by a classical triad of localized swelling, underlying sinus tracts, and production of grains or granules, but unusual presentations are also seen. It is classified into eumycetoma caused by the fungus, and actinomycetoma caused by the bacteria. The clinical presentation of both is almost similar and a definite diagnosis is essential before starting the treatment as it differs for both. Surgical debulking followed by a prolonged course of medical therapy now forms the mainstay of treatment due to the long course of the disease and suboptimal response. This review focuses on the various usual as well as unusual clinical presentations of mycetoma, established treatment regimens as well as recent changes in the mode of administration of drugs and newer drugs for mycetoma.

Gut-Restricted Selective Cyclooxygenase-2 (COX-2) Inhibitors for Chemoprevention of Colorectal Cancer.

Selective cyclooxygenase (COX)-2 inhibitors have been extensively studied for colorectal cancer (CRC) chemoprevention. Celecoxib has been reported to reduce the incidence of colorectal adenomas and CRC but is also associated with an increased risk of cardiovascular events. Here, we report a series of gut-restricted, selective COX-2 inhibitors characterized by high colonic exposure and minimized systemic exposure. By establishing acute ex vivo 18F-FDG uptake attenuation as an efficacy proxy, we identified a subset of analogues that demonstrated statistically significant in vivo dose-dependent inhibition of adenoma progression and survival extension in an APCmin/+ mouse model. However, in vitro-in vivo correlation analysis showed their chemoprotective effects were driven by residual systemic COX-2 inhibition, rationalizing their less than expected efficacies and highlighting the challenges associated with COX-2-mediated CRC disease chemoprevention.

Early Outcomes of Outpatient Management of Kidney Transplant Recipients with Coronavirus Disease 2019.

BACKGROUND AND OBJECTIVES: Outcomes of kidney transplant recipients diagnosed with coronavirus disease 2019 as outpatients have not been described. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We obtained clinical data for 41 consecutive outpatient kidney transplant recipients with known or suspected coronavirus disease 2019. Chi-squared and Wilcoxon rank sum tests were used to compare characteristics of patients who required hospitalization versus those who did not. RESULTS: Of 41 patients, 22 (54%) had confirmed coronavirus disease 2019, and 19 (46%) were suspected cases. Patients most commonly reported fever (80%), cough (56%), and dyspnea (39%). At the end of follow-up, 13 patients (32%) required hospitalization a median of 8 days (range, 1-16) after symptom onset, and 23 (56%) had outpatient symptom resolution a median of 12 days (4-23) after onset. Patients who required hospitalization were more likely to have reported dyspnea (77% versus 21%, P=0.003) and had higher baseline creatinine (median, 2.0 versus 1.3 mg/dl, P=0.02), but there were no other differences between groups. CONCLUSIONS: In an early cohort of outpatient kidney transplant recipients with known or suspected coronavirus disease 2019, many had symptomatic resolution without requiring hospitalization.

Heterogeneity and clonal relationships of adaptive immune cells in ulcerative colitis revealed by single-cell analyses.

Inflammatory bowel disease (IBD) encompasses a spectrum of gastrointestinal disorders driven by dysregulated immune responses against gut microbiota. We integrated single-cell RNA and antigen receptor sequencing to elucidate key components, cellular states, and clonal relationships of the peripheral and gastrointestinal mucosal immune systems in health and ulcerative colitis (UC). UC was associated with an increase in IgG1+ plasma cells in colonic tissue, increased colonic regulatory T cells characterized by elevated expression of the transcription factor ZEB2, and an enrichment of a γδ T cell subset in the peripheral blood. Moreover, we observed heterogeneity in CD8+ tissue-resident memory T (TRM) cells in colonic tissue, with four transcriptionally distinct states of differentiation observed across health and disease. In the setting of UC, there was a marked shift of clonally related CD8+ TRM cells toward an inflammatory state, mediated, in part, by increased expression of the T-box transcription factor Eomesodermin. Together, these results provide a detailed atlas of transcriptional changes occurring in adaptive immune cells in the context of UC and suggest a role for CD8+ TRM cells in IBD.