Epigenetic tuning of PD-1 expression improves exhausted T cell function and viral control.

PD-1 is a key negative regulator of CD8+ T cell activation and is highly expressed by exhausted T cells in cancer and chronic viral infection. Although PD-1 blockade can improve viral and tumor control, physiological PD-1 expression prevents immunopathology and improves memory formation. The mechanisms driving high PD-1 expression in exhaustion are not well understood and could be critical to disentangling its beneficial and detrimental effects. Here, we functionally interrogated the epigenetic regulation of PD-1 using a mouse model with deletion of an exhaustion-specific PD-1 enhancer. Enhancer deletion exclusively alters PD-1 expression in CD8+ T cells in chronic infection, creating a 'sweet spot' of intermediate expression where T cell function is optimized compared to wild-type and Pdcd1-knockout cells. This permits improved control of chronic infection without additional immunopathology. Together, these results demonstrate that tuning PD-1 via epigenetic editing can reduce CD8+ T cell dysfunction while avoiding excess immunopathology.

Obesity Shapes Metabolism in the Tumor Microenvironment to Suppress Anti-Tumor Immunity.

Obesity is a major cancer risk factor, but how differences in systemic metabolism change the tumor microenvironment (TME) and impact anti-tumor immunity is not understood. Here, we demonstrate that high-fat diet (HFD)-induced obesity impairs CD8+ T cell function in the murine TME, accelerating tumor growth. We generate a single-cell resolution atlas of cellular metabolism in the TME, detailing how it changes with diet-induced obesity. We find that tumor and CD8+ T cells display distinct metabolic adaptations to obesity. Tumor cells increase fat uptake with HFD, whereas tumor-infiltrating CD8+ T cells do not. These differential adaptations lead to altered fatty acid partitioning in HFD tumors, impairing CD8+ T cell infiltration and function. Blocking metabolic reprogramming by tumor cells in obese mice improves anti-tumor immunity. Analysis of human cancers reveals similar transcriptional changes in CD8+ T cell markers, suggesting interventions that exploit metabolism to improve cancer immunotherapy.

PTPN2 regulates the generation of exhausted CD8+ T cell subpopulations and restrains tumor immunity.

CD8+ T cell exhaustion is a state of dysfunction acquired in chronic viral infection and cancer, characterized by the formation of Slamf6+ progenitor exhausted and Tim-3+ terminally exhausted subpopulations through unknown mechanisms. Here we establish the phosphatase PTPN2 as a new regulator of the differentiation of the terminally exhausted subpopulation that functions by attenuating type 1 interferon signaling. Deletion of Ptpn2 in CD8+ T cells increased the generation, proliferative capacity and cytotoxicity of Tim-3+ cells without altering Slamf6+ numbers during lymphocytic choriomeningitis virus clone 13 infection. Likewise, Ptpn2 deletion in CD8+ T cells enhanced Tim-3+ anti-tumor responses and improved tumor control. Deletion of Ptpn2 throughout the immune system resulted in MC38 tumor clearance and improved programmed cell death-1 checkpoint blockade responses to B16 tumors. Our results indicate that increasing the number of cytotoxic Tim-3+CD8+ T cells can promote effective anti-tumor immunity and implicate PTPN2 in immune cells as an attractive cancer immunotherapy target.

Subsets of exhausted CD8+ T cells differentially mediate tumor control and respond to checkpoint blockade.

T cell dysfunction is a hallmark of many cancers, but the basis for T cell dysfunction and the mechanisms by which antibody blockade of the inhibitory receptor PD-1 (anti-PD-1) reinvigorates T cells are not fully understood. Here we show that such therapy acts on a specific subpopulation of exhausted CD8+ tumor-infiltrating lymphocytes (TILs). Dysfunctional CD8+ TILs possess canonical epigenetic and transcriptional features of exhaustion that mirror those seen in chronic viral infection. Exhausted CD8+ TILs include a subpopulation of 'progenitor exhausted' cells that retain polyfunctionality, persist long term and differentiate into 'terminally exhausted' TILs. Consequently, progenitor exhausted CD8+ TILs are better able to control tumor growth than are terminally exhausted T cells. Progenitor exhausted TILs can respond to anti-PD-1 therapy, but terminally exhausted TILs cannot. Patients with melanoma who have a higher percentage of progenitor exhausted cells experience a longer duration of response to checkpoint-blockade therapy. Thus, approaches to expand the population of progenitor exhausted CD8+ T cells might be an important component of improving the response to checkpoint blockade.

Author Correction: Subsets of exhausted CD8+ T cells differentially mediate tumor control and respond to checkpoint blockade.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Epigenetic silencing by SETDB1 suppresses tumour intrinsic immunogenicity.

Epigenetic dysregulation is a defining feature of tumorigenesis that is implicated in immune escape1,2. Here, to identify factors that modulate the immune sensitivity of cancer cells, we performed in vivo CRISPR-Cas9 screens targeting 936 chromatin regulators in mouse tumour models treated with immune checkpoint blockade. We identified the H3K9 methyltransferase SETDB1 and other members of the HUSH and KAP1 complexes as mediators of immune escape3-5. We also found that amplification of SETDB1 (1q21.3) in human tumours is associated with immune exclusion and resistance to immune checkpoint blockade. SETDB1 represses broad domains, primarily within the open genome compartment. These domains are enriched for transposable elements (TEs) and immune clusters associated with segmental duplication events, a central mechanism of genome evolution6. SETDB1 loss derepresses latent TE-derived regulatory elements, immunostimulatory genes, and TE-encoded retroviral antigens in these regions, and triggers TE-specific cytotoxic T cell responses in vivo. Our study establishes SETDB1 as an epigenetic checkpoint that suppresses tumour-intrinsic immunogenicity, and thus represents a candidate target for immunotherapy.

Expansion of Telestroke Coverage in Community Hospitals: Unifying Stroke Care and Reducing Transfer Rate.

OBJECTIVE: Telestroke (TS) service has been shown to improve stroke diagnosis timing and accuracy, facilitate treatment decisions, and decrease interfacility transfers. Expanding TS service to inpatient units at the community hospital provides an opportunity to follow up on stroke patients and optimize medical management. This study examines the outcome of expanding TS coverage from acute emergency room triage to incorporate inpatient consultation. METHODS: We studied the effect of expanding TS to inpatient consultation service at 19 regional hospitals affiliated with Promedica Stroke Network. We analyzed data pre- and post-TS expansion. We reviewed changes in TS utilization, admission rate, thrombolytic therapy, patient transfer rate, and diagnosis accuracy. RESULTS: Between January 2018 and June 2022, a total of 9,756 patients were evaluated in our stroke network (4,705 in pre- and 5,051 in the post-TS expansion). In the post-TS expansion period, stroke patients' admission at the spoke hospital increased from 18/month to 40/month, and for TIA from 11/month to 16/month. TS cart use increased from 12% to 35.2%. Patient transfers to hub hospital decreased by 31%. TS service expansion did not affect intravenous thrombolytic therapy rate or door-to-needle time. There was no difference in length of stay or readmission rate, and the patients at the spoke hospitals had a higher rate of home discharge 57.38% compared with 52.58% at hub hospital. INTERPRETATION: Telestroke service expansion to inpatient units helped decrease transfers and retain patients in their communities, increased stroke and TIA diagnosis accuracy, and did not compromise patients' hospitalization or outcome. ANN NEUROL 2024;95:576-582.

Loss of ADAR1 in tumours overcomes resistance to immune checkpoint blockade.

Most patients with cancer either do not respond to immune checkpoint blockade or develop resistance to it, often because of acquired mutations that impair antigen presentation. Here we show that loss of function of the RNA-editing enzyme ADAR1 in tumour cells profoundly sensitizes tumours to immunotherapy and overcomes resistance to checkpoint blockade. In the absence of ADAR1, A-to-I editing of interferon-inducible RNA species is reduced, leading to double-stranded RNA ligand sensing by PKR and MDA5; this results in growth inhibition and tumour inflammation, respectively. Loss of ADAR1 overcomes resistance to PD-1 checkpoint blockade caused by inactivation of antigen presentation by tumour cells. Thus, effective anti-tumour immunity is constrained by inhibitory checkpoints such as ADAR1 that limit the sensing of innate ligands. The induction of sufficient inflammation in tumours that are sensitized to interferon can bypass the therapeutic requirement for CD8+ T cell recognition of cancer cells and may provide a general strategy to overcome immunotherapy resistance.

Recruitment of a Middling Promiscuous Enzyme Drives Adaptive Metabolic Evolution in Escherichia coli.

A key step in metabolic pathway evolution is the recruitment of promiscuous enzymes to perform new functions. Despite the recognition that promiscuity is widespread in biology, factors dictating the preferential recruitment of one promiscuous enzyme over other candidates are unknown. Escherichia coli contains four sugar kinases that are candidates for recruitment when the native glucokinase machinery is deleted-allokinase (AlsK), manno(fructo)kinase (Mak), N-acetylmannosamine kinase (NanK), and N-acetylglucosamine kinase (NagK). The catalytic efficiencies of these enzymes are 103- to 105-fold lower than native glucokinases, ranging from 2,400 M-1 s-1 for the most active candidate, NagK, to 15 M-1 s-1 for the least active candidate, AlsK. To investigate the relationship between catalytic activities of promiscuous enzymes and their recruitment, we performed adaptive evolution of a glucokinase-deficient E. coli strain to restore glycolytic metabolism. We observed preferential recruitment of NanK via a trajectory involving early mutations that facilitate glucose uptake and amplify nanK transcription, followed by nonsynonymous substitutions in NanK that enhance the enzyme's promiscuous glucokinase activity. These substitutions reduced the native activity of NanK and reduced organismal fitness during growth on an N-acetylated carbon source, indicating that enzyme recruitment comes at a cost for growth on other substrates. Notably, the two most active candidates, NagK and Mak, were not recruited, suggesting that catalytic activity alone does not dictate evolutionary outcomes. The results highlight our lack of knowledge regarding biological drivers of enzyme recruitment and emphasize the need for a systems-wide approach to identify factors facilitating or constraining this important adaptive process.

Association of clonal hematopoiesis with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is associated with age and smoking, but other determinants of the disease are incompletely understood. Clonal hematopoiesis of indeterminate potential (CHIP) is a common, age-related state in which somatic mutations in clonal blood populations induce aberrant inflammatory responses. Patients with CHIP have an elevated risk for cardiovascular disease, but the association of CHIP with COPD remains unclear. We analyzed whole-genome sequencing and whole-exome sequencing data to detect CHIP in 48 835 patients, of whom 8444 had moderate to very severe COPD, from four separate cohorts with COPD phenotyping and smoking history. We measured emphysema in murine models in which Tet2 was deleted in hematopoietic cells. In the COPDGene cohort, individuals with CHIP had risks of moderate-to-severe, severe, or very severe COPD that were 1.6 (adjusted 95% confidence interval [CI], 1.1-2.2) and 2.2 (adjusted 95% CI, 1.5-3.2) times greater than those for noncarriers. These findings were consistently observed in three additional cohorts and meta-analyses of all patients. CHIP was also associated with decreased FEV1% predicted in the COPDGene cohort (mean between-group differences, -5.7%; adjusted 95% CI, -8.8% to -2.6%), a finding replicated in additional cohorts. Smoke exposure was associated with a small but significant increased risk of having CHIP (odds ratio, 1.03 per 10 pack-years; 95% CI, 1.01-1.05 per 10 pack-years) in the meta-analysis of all patients. Inactivation of Tet2 in mouse hematopoietic cells exacerbated the development of emphysema and inflammation in models of cigarette smoke exposure. Somatic mutations in blood cells are associated with the development and severity of COPD, independent of age and cumulative smoke exposure.

Integrated Devices: A New Regulatory Pathway to Promote Revolutionary Innovation.

Policy Points Current medical device regulatory frameworks date back half a century and are ill suited for the next generation of medical devices that involve a significant software component. Existing Food and Drug Administration efforts are insufficient because of a lack of statutory authority, whereas international examples offer lessons for improving and harmonizing domestic medical device regulatory policy. A voluntary alternative pathway built upon two-stage review with individual component review followed by holistic review for integrated devices would provide regulators with new tools to address a changing medical device marketplace.

Effective and adaptable: Four studies on the shortened attitude toward the color blue marker variable scale.

This research is an extension of the recent scale development efforts for the marker variable Attitude Toward the Color Blue (ATCB), which addresses the efficacy of multiple shorter permutations of the scale. The purpose of this study is to develop a shorter version of an ideal marker variable scale used to detect common method variance. Potential uses of the shorter version of ATCB include intensive longitudinal studies, implementation of experience sampling methodology, or any brief survey for which the original version might be cumbersome to implement repeatedly or appear very odd to the respondent when paired with only a few other substantive items. Study 1, uses all six-, five-, and four-item versions of ATCB in confirmatory factor analysis (CFA) marker technique tests on a bivariate relationship. Study 2 analyzes the best- and worst-performing versions of reduced lengths of the ATCB scale found in the first study on another bivariate relationship. Study 3 compares the original seven-item version, as well as randomly selected reduced length versions in a data set with 15 model relationships. Study 4 uses an experiment to determine the efficacy of providing respondents with one of three shorter ATCB scales in a model of three substantive variables. Our findings indicate that ATCB of different permutations and lengths can detect CMV successfully, and that researchers should choose the length of scale based on their survey length. We conclude that ATCB is adaptable for a variety of research situations, presenting it as a valuable tool for high-quality research.

Revisiting the manzamine biosynthetic hypothesis.

Covering: up to 2023The marine environment represents a rich yet challenging source of novel therapeutics. These challenges are best exemplified by the manzamine class of alkaloids, featuring potent bioactivities, difficult procurement, and a biosynthetic pathway that has eluded characterization for over three decades. This review highlights postulated biogenic pathways toward the manzamines, evaluated in terms of current biosynthetic knowledge and metabolic precedent.

Predictors of successful anti-inflammatory drug trials in patients with schizophrenia: A meta-regression and critical commentary.

Given evidence pointing toward a role for immune dysregulation in the pathogenesis of schizophrenia, anti-inflammatory agents are promising adjunctive treatments that have potential to support a causal relationship for inflammation and psychopathology and lead to novel treatments for individuals. Indeed, previous meta-analyses have demonstrated small-to-medium effect sizes (ES) in favor of various anti-inflammatory agents, though there is significant heterogeneity and challenges in the interpretation of this literature. Identifying predictors, including sociodemographic variables, trial duration, and/or symptoms themselves, of successful anti-inflammatory trials may help identify which patients who might benefit from these compounds. We performed a meta-regression analysis of 63 adjunctive anti-inflammatory trial arms (2232 patients randomized to adjunctive anti-inflammatory agents and 2207 patients randomized to placebo).Potential predictors of effect size estimates for changes in psychopathology scores from baseline to endpoint included geography, trial duration, sample size, age, sex, race, smoking, body mass index, illness duration, age of onset of psychosis, study quality score and psychopathology scores (total and subscale) at baseline. Geography (ß = 0.31, p = 0.011), smaller sample size (ß = 0.33, p = 0.009), and higher study quality score (ß = 0.44, p < 0.001) were significant predictors of larger ES estimates for change in total psychopathology in favor of anti-inflammatory agents. Smaller sample size (ß = 0.37, p = 0.034) and higher study quality score (ß = 0.55, p = 0.003) were significant predictors of larger ES estimates for change in negative psychopathology in favor of anti-inflammatory agents. Higher study quality score (ß = 0.46, p = 0.019) was a significant predictor of larger ES estimates for change in general psychopathology in favor of anti-inflammatory agents. These findings should be interpreted with caution given concerns of publication bias regarding the geographic differences and small study effects. The lack of an association with other demographic variables should be seen as a primary limitation of the literature that needs to be considered in future studies. The association with study quality score suggests that future anti-inflammatory trials must consider demographic variables known to be associated with inflammation (e.g., BMI and smoking) and evidence of increased baseline inflammation should be incorporated in study design. Moreover, evidence of target engagement and endpoints thoughts to be associated with increased inflammation should be considered as well.

Long-Acting Injectable Antipsychotics and Infections in Schizophrenia.

PURPOSE: Antipsychotics, particularly long-acting injectable (LAI) agents, are associated with decreased all-cause mortality. Antipsychotics are also associated with an increased prevalence of infections. We performed a systematic review and meta-analysis of the risk of infections in patients with schizophrenia treated with LAIs versus placebo. METHODS: We systematically searched PubMed and Food and Drug Administration package inserts for placebo-controlled studies of LAI antipsychotic use in schizophrenia. Random effects meta-analysis calculating odds ratios and 95% confidence intervals for any and site-specific infections were performed. RESULTS: The total study sample consisted of 2559 subjects with schizophrenia, with 867 receiving placebo and 1692 LAI antipsychotics. Long-acting injectable antipsychotic use was associated with a significant 1.75-fold increased odds of any infection versus placebo (2.4% vs 1.5%; odds ratio, 1.75; 95% confidence interval, 1.16-2.66; P = 0.008), although findings for specific infections did not reach statistical significance. The association between LAIs and infection was unrelated to study duration, age, sex, body mass index, and total psychopathology. CONCLUSIONS: Our findings suggest that LAIs are associated with a small, but significant, increased risk of infections. This association may be due to immunomodulatory effects of antipsychotics.

Yttrium-90 Activity Quantification in PET/CT-Guided Biopsy Specimens from Colorectal Hepatic Metastases Immediately after Transarterial Radioembolization Using Micro-CT and Autoradiography.

PURPOSE: To evaluate the yttrium-90 (90Y) activity distribution in biopsy tissue samples of the treated liver to quantify the dose with higher spatial resolution than positron emission tomography (PET) for accurate investigation of correlations with microscopic biological effects and to evaluate the radiation safety of this procedure. MATERIALS AND METHODS: Eighty-six core biopsy specimens were obtained from 18 colorectal liver metastases (CLMs) immediately after 90Y transarterial radioembolization (TARE) with either resin or glass microspheres using real-time 90Y PET/CT guidance in 17 patients. A high-resolution micro-computed tomography (micro-CT) scanner was used to image the microspheres in part of the specimens and allow quantification of 90Y activity directly or by calibrating autoradiography (ARG) images. The mean doses to the specimens were derived from the measured specimens' activity concentrations and from the PET/CT scan at the location of the biopsy needle tip for all cases. Staff exposures were monitored. RESULTS: The mean measured 90Y activity concentration in the CLM specimens at time of infusion was 2.4 ± 4.0 MBq/mL. The biopsies revealed higher activity heterogeneity than PET. Radiation exposure to the interventional radiologists during post-TARE biopsy procedures was minimal. CONCLUSIONS: Counting the microspheres and measuring the activity in biopsy specimens obtained after TARE are safe and feasible and can be used to determine the administered activity and its distribution in the treated and biopsied liver tissue with high spatial resolution. Complementing 90Y PET/CT imaging with this approach promises to yield more accurate direct correlation of histopathological changes and absorbed dose in the examined specimens.

In vivo CRISPR screening identifies Ptpn2 as a cancer immunotherapy target.

Immunotherapy with PD-1 checkpoint blockade is effective in only a minority of patients with cancer, suggesting that additional treatment strategies are needed. Here we use a pooled in vivo genetic screening approach using CRISPR-Cas9 genome editing in transplantable tumours in mice treated with immunotherapy to discover previously undescribed immunotherapy targets. We tested 2,368 genes expressed by melanoma cells to identify those that synergize with or cause resistance to checkpoint blockade. We recovered the known immune evasion molecules PD-L1 and CD47, and confirmed that defects in interferon-γ signalling caused resistance to immunotherapy. Tumours were sensitized to immunotherapy by deletion of genes involved in several diverse pathways, including NF-κB signalling, antigen presentation and the unfolded protein response. In addition, deletion of the protein tyrosine phosphatase PTPN2 in tumour cells increased the efficacy of immunotherapy by enhancing interferon-γ-mediated effects on antigen presentation and growth suppression. In vivo genetic screens in tumour models can identify new immunotherapy targets in unanticipated pathways.

Electronic nicotine delivery systems: the need for continued regulatory innovation.

The recent surge in electronic nicotine delivery systems (ENDS) or electronic cigarette use among both adolescents and adults challenged tobacco regulatory frameworks worldwide. In this article, we review recent US Food and Drug Administration regulatory approaches to tobacco products, including attempts to regulate nicotine concentration and address youth use. We examine recent drives to promote a harm reduction approach in other product markets such as opioids, where the use of methadone and related therapies promote the public health. We describe the potential of a harm reduction framework for ENDS regulation based on tiered nicotine exposure standards coupled with risk-based product distribution controls that would enable ENDS products to meet the 'Appropriate for the Protection of the Public Health' standard required for tobacco product market entry. A harm reduction approach to ENDS regulation could help countries achieve the laudable public health goals of transitioning existing combustion cigarette users to ENDS products while preventing adolescent ENDS use and subsequent nicotine addiction.

Using Trauma Video Review to Assess EMS Handoff and Trauma Team Non-Technical Skills.

OBJECTIVE: Handoffs by emergency medical services (EMS) personnel suffer from poor structure, inattention, and interruptions. The relationship between the quality of EMS communication and the non-technical performance of trauma teams remains unknown. METHODS: We analyzed 3 months of trauma resuscitation videos (highest acuity activations or patients with an Injury Severity Score [ISS] of ≥15). Handoffs were scored using the mechanism-injury-signs-treatment (MIST) framework for completeness (0-20), efficiency (category jumps), interruptions, and timeliness. Trauma team non-technical performance was scored using the Trauma Non-Technical Skills (T-NOTECHS) scale (5-15). RESULTS: We analyzed 99 videos. Handoffs lasted a median of 62 seconds [IQR: 43-74], scored 11 [10-13] for completeness, and had 2 [1-3] interruptions. Most interruptions were verbal (85.2%) and caused by the trauma team (64.9%). Most handoffs (92%) were efficient with 2 or fewer jumps. Patient transfer during handoff occurred in 53.5% of the videos; EMS providers giving handoff helped transfer in 69.8% of the Primary surveys began during handoff in 42.4% of the videos. Resuscitation teams who scored in the top-quartile on the T-NOTECHS (>11) had higher MIST scores than teams in lower quartiles (13 [11.25-14.75] vs. 11 [10-13]; p < .01). There were no significant differences in ISS, efficiency, timeliness, or interruptions between top- and lower-quartile groups. CONCLUSIONS: There is a relationship between EMS MIST completeness and high performance of non-technical skill by trauma teams. Trauma video review (TVR) can help identify modifiable behaviors to improve EMS handoff and resuscitation efforts and therefore trauma team performance.

The Local Market of Major Teaching Hospitals.

OBJECTIVE: The purpose of this study was to describe the local communities served by major teaching hospitals. METHODS: Using a dataset of hospitals around the United States provided by the Association of American Medical Colleges, we identified major teaching hospitals (MTHs) using the Association of American Medical Colleges' definition of those with an intern-to-resident bed ratio above 0.25 and more than 100 beds. We defined the local geographic market surrounding these hospitals as the Dartmouth Atlas hospital service area (HSA). Using MATLAB R2020b software, data from each ZIP Code Tabulation Area from the US Census Bureau's 2019 American Community Survey 5-Year Estimate Data tables were grouped by HSA and attributed to each MTH. One-sample t tests were used to evaluate for statistical differences between the HSAs and the US average data. We further stratified the data into regions as defined by the US Census Bureau: West, Midwest, Northeast, and South. One-sample t tests were used to evaluate for statistical differences between MTH HSA regional populations with their respective US regional population. RESULTS: The local population surrounding 299 unique MTHs covered 180 HSAs and was 57% White, 51% female, 14% older than 65 years old, 37% with public insurance coverage, 12% with any disability, and 40% with at least a bachelor's degree. Compared with the overall US population, HSAs surrounding MTHs had higher percentages of female residents, Black/African American residents, and residents enrolled in Medicare. In contrast, these communities also showed higher average household and per capita income, higher percentages of bachelor's degree attainment, and lower rates of any disability or Medicaid insurance. CONCLUSIONS: Our analysis suggests that the local population surrounding MTHs is representative of the wide-ranging ethnic and economic diversity of the US population that is advantaged in some ways and disadvantaged in others. MTHs continue to play an important role in caring for a diverse population. To support and improve policy related to the reimbursement of uncompensated care and care of underserved populations, researchers and policy makers must work to better delineate and make transparent local hospital markets.