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Variance Polygenic Scores (vPGS) as a Tool for Studying Gene-Environment Interactions Associated With Refractive Error.

PURPOSE: Conventional polygenic scores predict an individual's phenotype based on their genetics. By contrast, variance polygenic scores (vPGS) quantify genetic predisposition to phenotypic variance. We tested the hypothesis that a vPGS for refractive error can identify individuals with increased susceptibility to environmental risk factors for myopia. METHODS: Six vPGS construction strategies were evaluated in UK Biobank participants: three variance heterogeneity genome-wide association study (vGWAS) methods and two reweighting schemes. vPGS performance was assessed using two metrics: (i) "Diff"-difference in phenotypic variance in vPGS decile ten versus one; (ii) Spearman correlation of phenotypic variance versus vPGS decile. The optimal vPGS was used to test for vPGS × time spent reading or vPGS × time spent outdoors interactions in children aged 15 years (ALSPAC cohort; n = 3471). RESULTS: Of the vGWAS methods, conditional quantile regression outperformed SCAMPI and Levene's Test. Of the re-weighting schemes, LDpred2 outperformed pruning and thresholding. In an independent sample of UK Biobank participants (n = 19,470), the top-performing vPGS successfully stratified individuals into groups with increasing variance in refractive error, even after adjusting for a conventional PGS (Diff: 2.55, 95% confidence interval [CI], 1.64-3.47; Spearman correlation = 0.87; 95% CI, 0.43-0.93). However, in ALSPAC participants, there was minimal support for vPGS interactions with time reading (P = 0.80) or time outdoors (P = 0.89). CONCLUSIONS: A novel vPGS successfully stratified individuals into groups with relatively high or low genetic susceptibility to refractive error variance. However, the vPGS could not identify individuals at enhanced risk from lifestyle risk factors for myopia.

Humans

Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore region.

The sodium (Na+) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (NaVs and CaVs, respectively). Unlike NaVs and CaVs, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145, and Y1436) that block these openings. Structural data suggest that occluded fenestrations underlie the pharmacological resistance of NALCN, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned residues with alanine (AAAA) and compared the effects of NaV, CaV, and NALCN blockers on both wild-type (WT) and AAAA channels. Most compounds behaved in a similar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cavity through distinct fenestrations, implying structural specificity to their modes of access. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug binding site(s) within the pore region. Intrigued by the activity of 2-APB and its analogues, we tested compounds containing the diphenylmethane/amine moiety on WT channels. We identified clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the pharmacological resistance of NALCN, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties.

Binding Sites

Selective saccular plasticity under microgravity links peripheral transcriptomic remodeling to postflight vestibular dysfunction.

Long-duration exposure to microgravity disrupts human balance and spatial orientation, yet the molecular mechanisms underlying vestibular adaptation to spaceflight remain poorly understood. Here, we tested the hypothesis that the saccule, the primary gravity-sensing otolith organ, undergoes selective remodeling during spaceflight and contributes to transient postflight postural instability. Using a cross-species approach, we combined transcriptomic analysis of mouse otolith organs with physiological assessments in astronauts. Laser microdissection-based RNA sequencing of mouse otolith sensory epithelia after a 35-d spaceflight revealed pronounced, organ-specific transcriptomic remodeling in the saccule, whereas the utricle remained stable. Principal component and clustering analyses demonstrated that the saccular transcriptome shifted toward an utricle-like profile under microgravity, accompanied by changes in genes related to synaptic and neuronal function. Promoter motif analysis identified NFAT-associated transcriptional networks, suggesting Ca2+-dependent regulation of synaptic plasticity as a potential molecular substrate of gravity-dependent adaptation. In parallel, vestibular testing in astronauts following long-duration missions (157 to 328 d) revealed selective attenuation of saccule-mediated cervical vestibular-evoked myogenic potentials and increased postural sway immediately after return to Earth, while utricle-mediated responses and semicircular canal function were preserved. Both saccular function and postural stability recovered within approximately 10 d. Notably, early postflight postural instability was partially mitigated by noisy galvanic vestibular stimulation, consistent with stochastic resonance-mediated sensory enhancement. Together, these findings identify the saccule as a plastic gravity sensor and establish a mechanistic link between peripheral molecular remodeling and functional balance deficits after spaceflight, providing a framework for developing countermeasures to facilitate vestibular readaptation during human space exploration.

Animals

Weak but repeated patterns of co-introgression of nuclear OXPHOS genes and mitochondrial DNA in Iberian wall lizards.

In this study, we took advantage of the previously reported instances of mitochondrial DNA capture in the Podarcis Iberian group, a speciose group of Iberian wall lizards, to test the hypothesis that nuclear genes from the OXPHOS (Oxidative phosphorylation) chain can co-introgress with the mitochondria as an evolutionary response to mitigate the costs of mitonuclear incompatibilities. Using dense population sampling and transcriptome data, we generated capture-sequence datasets for nuclear OXPHOS chain genes (nucOXPHOS), random nuclear loci (nucControl) and the complete mitochondrial genome. Phylogenetic analyses of nuclear and mitochondrial genes confirmed two previously identified events of mitochondrial introgression in the Podarcis Iberian group and revealed two new cases. Three of these cases have led to complete local mitochondrial DNA replacements, where the introgressed mitotypes have replaced the native ones in several populations, and involve a currently unknown and presumably extinct donor species, so-called "ghost lineage". Detecting introgression from ghost lineages, whose genomes are not accessible, remains challenging. To overcome this issue, we designed or adapted several tests aimed at detecting differential signals of introgression between our nucOXPHOS and nucControl gene sets. One of these tests, based on the effects of introgression on branch lengths in phylogenetic trees, uncovered a weak but consistently significant signal of partial co-introgression of nucOXPHOS genes compared to the genomic background (represented by the nucControl gene set) in three out of four cases of mtDNA introgression.

mitochondrial introgression

Phylogenomic subsampling and upsampling for efficient evolutionary analyses of big data.

Long runtimes, high memory demands, and reliance on high-performance computing impede phylogenomic analyses. We review a scalable phylogenomic subsampling with upsampling (PSU) framework, in which small subsamples of sites from a concatenated alignment are expanded by upsampling before inference, and the resulting analyses are then aggregated to obtain evolutionary estimates. PSU harnesses the fact that the computational cost of maximum likelihood analysis is strongly influenced by the number of distinct site patterns in the concatenated alignment, whereas statistical power depends primarily on the amount of evolutionary information represented by the total number of sites and substitutions. By reducing the former while restoring the latter through upsampling, PSU can approximate many full-data analyses at substantially lower computational cost. Analysis of simulated and empirical datasets shows that PSU can accurately estimate bootstrap support values, select the optimal substitution model, test evolutionary hypotheses, and infer branch lengths, divergence times, and associated uncertainty measures, while reducing runtime and memory requirements by orders of magnitude. PSU also provides distributions of inferred clade support across independent subsamples, enabling detection of conflicting phylogenetic signals that may remain hidden in conventional bootstrap analysis. Automated tuning of subsample size, the number of subsamples, and the number of upsampling replicates make PSU practical across diverse datasets. We suggest that PSU is a general strategy for scalable phylogenomic inference using a broad range of statistical methods. By enabling analyses of genome-scale alignments on commodity hardware, PSU broadens research access and reduces environmental and infrastructural costs of big-data phylogenomics.

confidence limits

Mutation of the gidB gene causes intrinsic streptomycin resistance in Bacillus velezensis.

Bacillus velezensis strain DMB07, isolated from the traditional fermented Korean soybean meju, exhibits resistance to streptomycin [minimum inhibitory concentration (MIC) 128 mg/L]. To shed light on the genetic background behind this phenotype, this study determined the complete genome sequence of strain DMB07 and compared it with the genomes of two B. velezensis strains that are sensitive to streptomycin. Compared with the streptomycin-sensitive strains, in strain DMB07 there was a mutation of a nucleotide (C58T) of the 16 S rRNA (guanine527-N7)-methyltransferase gene (gidB) that leads to a change in the amino acid sequence of the protein (Arg20Cys). This sequence of gidB gene was previously linked with streptomycin resistance. To test the hypothesis that this change in the gidB gene sequence of strain DMB07 confers streptomycin resistance, a temperature-sensitive plasmid, pIMAY-tgidBT58C, was constructed for site-directed mutation (from thymine to cytosine) of nucleotide 58 of gidB in strain DMB07. The resulting strain, DMB07gidBT58C, showed the decreased MIC value (32 mg/L) against streptomycin. Furthermore, introduction of the wild-type gidB gene into strain DMB07gidBT58C resulted in recovery of the MIC for streptomycin to 128 mg/L. Thus, a single mutation of the nucleotide sequence of the gidB gene can confer resistance to streptomycin.

Streptomycin

Phylogenomic subsampling and upsampling for efficient evolutionary analyses of big data.

Long runtimes, high memory demands, and reliance on high-performance computing impede phylogenomic analyses. We review a scalable phylogenomic subsampling with upsampling (PSU) framework to address this challenge, which reduces runtime and memory requirements by orders of magnitude. In PSU, small subsamples of sites from a concatenated alignment are analyzed, which are expanded by upsampling before inference, and the resulting inferences are aggregated to obtain evolutionary estimates. PSU harnesses the fact that the computational cost of maximum likelihood analysis is strongly influenced by the number of distinct site patterns in the concatenated alignment, whereas statistical power depends primarily on the amount of evolutionary information represented by the total number of sites and substitutions. By reducing the former while restoring the latter through upsampling, PSU can approximate many full-alignment analyses at substantially lower computational cost. Analysis of simulated and empirical datasets shows that PSU can accurately estimate bootstrap support values, select the optimal substitution model, test evolutionary hypotheses, and infer branch lengths, divergence times, and associated uncertainty measures. PSU also provides distributions of inferred clade support across independent subsamples, enabling detection of conflicting phylogenetic signals that may remain hidden in conventional bootstrap analysis of concatenated alignments. Automated tuning of subsample size, the number of subsamples, and the number of upsampling replicates make PSU practical. We suggest that PSU is a general approach for scalable phylogenomic inference using a broad range of statistical methods. By enabling analyses of genome-scale alignments on commodity hardware, PSU broadens research access and reduces environmental and infrastructural costs of big-data phylogenomics.

Phylogeny

Design, rationale, and baseline patient characteristics for the Sickle Cell Disease and CardiovAscular Risk-Red cell Exchange (SCD-CARRE) trial.

BACKGROUND: Despite wide utilization of automated red blood cell exchange (RBCX) transfusion in adult patients with sickle cell disease (SCD), no consensus or quality efficacy data exist on its use. The Sickle Cell Disease and CardiovAscular Risk- Red cell Exchange (SCD-CARRE) trial tests the hypothesis that an automated chronic RBCX transfusion strategy reduces acute health care encounters and death while improving quality of life and end-organ function (cardiac, pulmonary and renal) in participants with SCD that are at high risk of death. METHODS: Adult patients with SCD with elevated tricuspid regurgitant jet velocity (TRV) and/or chronic kidney disease were considered to be at high risk of death and were randomly assigned to RBCX plus standard of care vs standard of care alone. Participants assigned to RBCX received 12 months of exchange transfusions to maintain target pretransfusion hemoglobin S% < 30%, post-transfusion hemoglobin S% < 20%, and post-transfusion hemoglobin concentration &#x2265;10 g/dL. All study participants were managed according to NHLBI/ASH/ATS Expert Panel guidelines. The primary endpoint was the number of SCD acute health care encounters or death over 13 months. Secondary endpoints included measures of cardiovascular and renal function, exercise capacity, patient reported outcomes (all collected at baseline, and months 4, 8, and 12), and transfusion-related adverse events (collected monthly). RESULTS: Between 2020 and 2025, the SCD-CARRE trial randomized 173 participants at 23 sites across 3 countries. Enrolled participants had mean (SD) age of 45.8 (11.8) years and 54% were female. At baseline, participants had average TRV of 2.8 (0.5) m/s such that 45.9% had a TRV between 2.5 to 2.9 m/sec and 28.1% had a TRV &#x2265; 3.0 m/sec. The median (Q1, Q3) eGFR in this cohort was 60 (36, 110) mL/min/1.73 m2. The median (Q1, Q3) 6-minute walk test distance was 375 meters (309, 439), the median daily steps were 3,728 (2,187, 5,821), and participants experienced a median (Q1, Q3) of 2 (1, 5) pain episodes in the year prior to randomization. The trial results are pending. CONCLUSIONS: The SCD-CARRE trial successfully enrolled a cohort of n = 173 adults with SCD. This study highlights a rationale to evaluate the effect of automated chronic RBCX transfusion strategy plus standard of care as compared to standard of care alone in SCD patients at high risk of death with a focus on patient centered outcomes, preservation of cardiovascular function, end-organ complications and death. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT04084080, https://clinicaltrials.gov/study/NCT04084080.

Adult

Resolving the "Yucca queretaroensis problem": Phylogenomic analysis of Yucca reveals the identity of an enigmatic species and the origin of an obligate pollination mutualism.

PREMISE: The genus Yucca is a group of ~50 species of woody monocots endemic to the North American arid regions. Their obligate pollination mutualism with yucca moths is considered a "textbook example" of coevolution and is hypothesized to have promoted rapid diversification. However, testing this hypothesis has been difficult due to uncertainty about the placement of a rogue taxon, Yucca queretaroensis, a rare endemic of the Sierra Gorda region of central Mexico. Past work placed this species in different positions within the Agavoideae, producing starkly different age estimates for Yucca (25 to 4 million years). METHODS: We generated new sequence capture data for 353 nuclear genes and for all coding regions of the plastid genome from wild-collected plants and samples included in previous studies to provide a new phylogeny and new age estimate for Yucca. RESULTS: The data presented here suggest that Y. queretaroensis is closely related to other species of Yucca. A relaxed molecular clock analysis of the plastid genome produced an estimated age for the genus of approximately 6.8 million years. CONCLUSIONS: The results resolve a mystery that has bedeviled evolutionary biologists for decades and provide a surprisingly young estimate for the age of Yucca, suggesting rapid diversification. The past difficulties in identifying the correct placement of Y. queretaroensis appear to be the product of laboratory errors, mistakes in field identification, and frequent hybridization with co-distributed taxa. The "Yucca queretaroensis problem" reaffirms the essential role for traditional botanical tools in phylogenomics.

ASTRAL

A Triple-Blinded, Randomized, Controlled Trial Comparing Hydromorphone vs. Fentanyl for Children Undergoing Tonsillectomy.

BACKGROUND: Tonsillectomy is one of the most frequently performed pediatric surgeries; however, little evidence guides the choice of intraoperative opioids in a population at an elevated risk for perioperative respiratory complications. This study tested the hypothesis that fewer children who received hydromorphone during tonsillectomy would require postoperative "rescue" opioids compared to children who received fentanyl. METHODS: We conducted a triple-blind, randomized, controlled trial to compare intravenous hydromorphone versus fentanyl in pediatric patients undergoing tonsillectomy. Children aged 2-15&#x2009;years undergoing bilateral tonsillectomy or adenotonsillectomy were assigned (1:1) to receive hydromorphone (10&#x2009;mcg/kg) or fentanyl (1&#x2009;mcg/kg) intraoperatively. The primary endpoint was the number of patients who required rescue intravenous opioid analgesia following endotracheal extubation. Secondary endpoints included pain scores, pulse oximetry saturations, postoperative nausea, time in the recovery room, morphine milligram equivalents in the post-anesthesia care unit, and adverse events. RESULTS: A total of 188 children underwent randomization, and 180 were analyzed (90 in each group). The median age was 5&#x2009;years (interquartile range: 3-7&#x2009;years). Rescue intravenous opioid was administered to 48 (53%) children who received intraoperative hydromorphone and 66 (73%) children who received intraoperative fentanyl (difference, 20.0 percentage points; 95% confidence interval, 6.2-33.8) (p&#x2009;=&#x2009;0.005). Children who received hydromorphone also had lower mean pain scores for the first 15&#x2009;min postoperatively and lower median morphine milligram equivalents. The incidence of adverse events was similar between the two groups. CONCLUSIONS: This study in children undergoing tonsillectomy found that intraoperative hydromorphone resulted in improved analgesia in the recovery room compared to fentanyl. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04230681.

Adolescent

In vitro fertilization-conceived offspring exhibit altered Long Interspersed Nuclear Elements-1 retrotransposition dynamics associated with long-term disease risks.

BACKGROUND: In vitro fertilization has transformed reproductive medicine, yet offspring conceived through in vitro fertilization display elevated risks for diverse long-term health conditions, with underlying mechanisms unclear. Long Interspersed Nuclear Elements-1, a mobile genetic element responsive to environmental stress, represents a potential mediator. OBJECTIVE: This study aimed to test the hypothesis that in vitro fertilization procedures may act as an embryonic stressor that alters Long Interspersed Nuclear Elements-1 dynamics, potentially contributing to genomic instability associated with long-term disease susceptibility. STUDY DESIGN: Umbilical cord blood or peripheral blood from 33 in vitro fertilization and 42 naturally conceived neonates were collected for whole-genome sequencing. Total Long Interspersed Nuclear Elements-1 proportion in individual genome was counted with Bowtie2 software. De novo Long Interspersed Nuclear Elements-1 insertion and Long Interspersed Nuclear Elements-1 deletion were detected with Mobile Element Locator Tool. Three parent-matched in vitro fertilization-naturally conceived sibling pairs were included to control for genetic background. Disease association analysis was performed for genes within 500 kb of differential Long Interspersed Nuclear Elements-1 sites in The Database for Annotation, Visualization and Integrated Discovery (DAVID). Statistical analysis was performed using the R language. RESULTS: In vitro fertilization offspring demonstrate elevated global Long Interspersed Nuclear Elements-1 content compared to naturally conceived controls (P=.04). This finding was corroborated in 3 sibling pairs from identical genetic backgrounds, where in vitro fertilization-conceived children consistently exhibited higher Long Interspersed Nuclear Elements-1 levels than their naturally conceived siblings. Eleven genomic loci with differential Long Interspersed Nuclear Elements-1 insertion frequencies and 14 loci with differential Long Interspersed Nuclear Elements-1 deletion frequencies between in vitro fertilization offspring and naturally conceived controls were identified. Notably, these differential Long Interspersed Nuclear Elements-1 sites demonstrated significant enrichment near genes implicated in metabolic, cardiovascular, neuropsychiatric, and neoplastic diseases, conditions associated with in vitro fertilization conception. CONCLUSION: These findings provide preliminary evidence that in vitro fertilization conception is associated with increased Long Interspersed Nuclear Elements-1 content and altered genomic distribution of Long Interspersed Nuclear Elements-1 elements. The proximity of these differential Long Interspersed Nuclear Elements-1 sites to disease-associated genes suggests a plausible genomic mechanism linking in vitro fertilization-associated embryonic stress to elevated disease risk. This work provides valuable molecular insights that may inform the ongoing discussion about assisted reproductive technology safety and suggests that continued attention to genomic integrity in in vitro fertilization-conceived individuals would be beneficial.

Humans

Binding capacity of Intravenous immunoglobulin G to BK polyomavirus determines its anti-BK polyomavirus activity in infected cultures.

BK polyomavirus (BKPyV) causes disease in immunocompromised individuals. This study tested the hypothesis that the antiviral efficacy of intravenous immunoglobulin (IVIG) against BKPyV depends on the relationship between its virus-binding capacity and the viral burden. We first quantified the BKPyV-binding capacity of IVIG and then characterized BKPyV replication in kidney-derived HK-2 and HEK293&#x202f;cells and in HEL cells under IVIG treatment. Subsequently, we analyzed the efficacy of IVIG at 0.03-10&#x202f;mg/mL against low-multiplicity of infection (MOI) and high-MOI infection in relation to the BKPyV-binding capacity of IVIG. BKPyV productively infected all three cell lines, with 14-day replication cycles of 2.2, 4.0, and 7.0 in HK-2, HEK293, and HEL cells, respectively, indicating that HEL cells were the most permissive. IVIG bound approximately 108 copies of BKPyV DNA per milligram. In the low-MOI infection model, where the total viral load remained within this estimated binding capacity, IVIG showed clear neutralizing activity, significantly reducing viral spread, viral DNA levels, and the number of VP1-positive cells in a dose-dependent manner (p&#x202f;<&#x202f;0.001). In contrast, in the high-MOI infection model, the viral load appeared to be high relative to the estimated IVIG binding capacity even at 10&#x202f;mg/mL, and IVIG showed little or no neutralizing effect on viral production or spread of infected cells. These findings identify an experimental relationship between IVIG binding capacity, viral burden, and antiviral efficacy and suggest that the antiviral effect of IVIG is greatest when administered early, thereby supporting further clinical evaluation of early or preemptive IVIG administration.

Humans

Increased acetylation of H3K14 in the genomic regions that encode trained immunity enzymes in lysophosphatidylcholine-activated human aortic endothelial cells - Novel qualification markers for chronic disease risk factors and conditional DAMPs.

To test our hypothesis that proatherogenic lysophosphatidylcholine (LPC) upregulates trained immunity pathways (TIPs) in human aortic endothelial cells (HAECs), we conducted an intensive analyses on our RNA-Seq data and histone 3 lysine 14 acetylation (H3K14ac)-CHIP-Seq data, both performed on HAEC treated with LPC. Our analysis revealed that: 1) LPC induces upregulation of three TIPs including glycolysis enzymes (GE), mevalonate enzymes (ME), and acetyl-CoA generating enzymes (ACE); 2) LPC induces upregulation of 29% of 31 histone acetyltransferases, three of which acetylate H3K14; 3) LPC induces H3K14 acetylation (H3K14ac) in the genomic DNA that encodes LPC-induced TIP genes (79%) in comparison to that of in LPC-induced effector genes (43%) including ICAM-1; 4) TIP pathways are significantly different from that of EC activation effectors including adhesion molecule ICAM-1; 5) reactive oxygen species generating enzyme NOX2 deficiency decreases, but antioxidant transcription factor Nrf2 deficiency increases, the expressions of a few TIP genes and EC activation effector genes; and 6) LPC induced TIP genes(81%) favor inter-chromosomal long-range interactions (CLRI, trans-chromatin interaction) while LPC induced effector genes (65%) favor intra-chromosomal CLRIs (cis-chromatin interaction). Our findings demonstrated that proatherogenic lipids upregulate TIPs in HAECs, which are a new category of qualification markers for chronic disease risk factors and conditional DAMPs and potential mechanisms for acute inflammation transition to chronic ones. These novel insights may lead to identifications of new cardiovascular risk factors in upregulating TIPs in cardiovascular cells and novel therapeutic targets for the treatment of metabolic cardiovascular diseases, inflammation, and cancers. (total words: 245).

Acetylation

The phosphatidylserine targeting antibody bavituximab plus pembrolizumab in unresectable hepatocellular carcinoma: a phase 2 trial.

Immune checkpoint inhibitors targeting PD-1/L1 have modest efficacy in hepatocellular carcinoma as single agents. Targeting membranous phosphatidylserine may induce pro-inflammatory and -immune stimulating effects that enhance immunotherapy activity. This hypothesis was tested in a single-arm phase 2 trial evaluating frontline bavituximab, a phosphatidylserine targeting antibody, plus pembrolizumab (anti-PD-1) in patients with unresectable hepatocellular carcinoma (NCT03519997). The primary endpoint was investigator-assessed objective response rate among evaluable patients, and secondary end points included progression-free survival, incidence of adverse events, overall survival, and duration of response. Among 28 evaluable patients, the confirmed response rate was 32.1%, which met the pre-specified endpoint, and the median progression-free survival was 6.3 months (95% CI, 1.3-11.3 months). Treatment related-adverse events of any grade occurred in 45.7% of patients, with grade 3 or greater adverse events in 14.3% of patients. Adverse events of any cause were observed in 33 patients (94.3%), with grade 3 or greater adverse events in 11 patients (31.4%). Prespecified exploratory analyses of baseline tumor specimens showed that a depletion of B cells, and the presence of fibrotic tissue and expression of immune checkpoints in stroma was associated with tumor response. These results suggest that targeting phosphatidylserine may lead to synergistic effects with PD-1 blockade without increasing toxicity rates, and future studies on this therapeutic strategy may be guided by biomarkers characterizing the pre-treatment tumor microenvironment.

Humans

Brown bullhead catfish melanoma represents a novel transmissible cancer.

Since 2012, brown bullhead catfish (Ameiurus nebulosus) in a lake that&#xa0;spans Vermont, USA, and Quebec, Canada, have shown a high rate of melanomas, suggesting a causal contaminant or contagion1. We tested the hypothesis that this affliction represents a clonally transmissible cancer, a rare phenomenon in which cancer cells themselves spread between individuals, behaving more like parasites than conventional tumours2. Whole-genome sequencing of tumour and matched non-tumour host tissues revealed that tumour mitochondrial and nuclear genomes are more closely related to each other than to their hosts or unaffected fish. Hundreds of thousands of genetic variants are shared among tumour samples but are&#xa0;absent from host fish, vastly exceeding levels seen in conventional cancers3. These findings indicate that melanoma in these brown bullheads represents the fourth documented type of naturally occurring transmissible cancer in animals, after dogs4, Tasmanian devils5 and several bivalve species6-13. This raises important questions about the cancer's origin, the mode of transmission and the long-term impact on fish populations.

Animals

Consolidation Therapy Based on Mutation Clearance in Acute Myeloid Leukemia.

BACKGROUND: Optimal consolidation therapy for patients with intermediate-risk acute myeloid leukemia (AML) in first complete remission (CR1) is controversial. Retrospective studies have suggested that the clearance of leukemia-associated mutations (LAMs) in CR1 may predict lower relapse risk and better outcomes with high-dose cytarabine (HiDAC) consolidation. We tested this hypothesis prospectively. METHODS: We performed a phase II, multicenter study of intermediate-risk, transplant-eligible, de novo AML in patients 18-60 years of age who achieved a complete remission (CR) or CR with incomplete count recovery (CRi) after induction therapy. Tumor and normal whole-exome sequencing was performed at presentation to identify somatic LAMs (median &#x223c;30 LAMs/patient). In remission marrow samples, LAM variant allele frequencies (VAFs) were then remeasured using a VAF cutoff of less than 2.5% to define clearance. Patients who met this LAM clearance threshold received HiDAC consolidation, whereas those with persistent LAMs (VAF &#x2265;2.5%) were recommended to undergo allogeneic hematopoietic cell transplantation. The primary endpoint compared relapse-free survival (RFS) of intermediate-risk patients with complete LAM clearance to historical cohorts with intermediate-risk AML who received HiDAC-based regimens in CR1. To account for an unplanned interim assessment, the significance threshold for the primary analysis was 0.01. RESULTS: Among 100 patients who were evaluated, intermediate-risk patients who cleared all LAMs in CR1 (n=33) had a median RFS of 33.1 months (95% confidence interval, 11.7-NA) compared to a median RFS of 11.7 months in the historical cohort (n=239; 95% confidence interval, 9.9-15.6, P=0.015). CONCLUSIONS: Among patients with intermediate-risk AML, clearance of LAMs after induction, followed by HiDAC consolidation in CR1, was associated with longer RFS compared with similarly treated historical controls. Although this result did not meet the prespecified threshold for statistical significance, the reported association sets the stage for a randomized trial to further evaluate this strategy. (ClinicalTrials.gov number, NCT02756962.).

Humans

Human airspace macrophage signatures are conserved during sterile lung injury and repair.

RATIONALE: Airspace macrophages (AM) are implicated in both persistent inflammation and tissue repair following acute lung injury. Distinct subsets of AM are associated with lung pathology in humans but whether unique AM signatures are specific to disease states or represent a conserved response to lung inflammation is unknown. OBJECTIVES: We sought to test the hypothesis that conserved subsets of inflammatory and reparative AM could be identified by transcriptional programing in a human model of self-resolving acute lung injury. METHODS: Fifteen subjects underwent bronchoscopic lavage (BAL) before and at a pre-assigned time point after endobronchial exposure to bacterial endotoxin. BAL cells were subjected to single cell RNA sequencing and longitudinal assessment of AM programing during resolution of inflammation and lung repair was performed. MEASUREMENTS AND MAIN RESULTS: We identify transcriptionally distinct subsets of tissue resident and recruited AM present at all time points, in all subjects. Two recruited AM populations increase following inflammation, one which aligns with classical monocytes (MoAM) and one with interstitial macrophages (IAM). AM subsets display unique patterns of gene expression throughout the time course. Comparison of subset-specific markers to those identified in disease states reveals that IAM express many so-called "pathogenic" markers during normal lung repair. CONCLUSIONS: By applying a uniform inflammatory stimulus to healthy adults and examining BAL cells obtained at precise time points thereafter, we construct a time-resolved kinetic of AM transcriptional programing during typical lung repair. Our data demonstrate that IAM share transcriptional similarity to AM identified in disease states and suggest they may reflect a conserved cellular response to tissue injury.

Journal Article

Landscape heterogeneity, forest structure, and mammalian host diversity shape tick density and prevalence of the causative agent of Lyme borreliosis.

Ticks, particularly Ixodes ricinus, and the associated Lyme borreliosis risk, represent key concerns within the One Health framework, prompting extensive research in this field. However, comprehensive studies that jointly consider landscape characteristics, local forest structure and management, climate, and host community composition-alongside direct measures of tick density and infection status with Borrelia spp., the bacterial agents causing Lyme borreliosis, are scarce. In this study, we test the hypothesis that habitat diversity exerts a dilution effect, primarily by supporting greater diversity of mammal hosts. Therefore, we examined I. ricinus tick density and Borrelia spp. prevalence in relation to a comprehensive set of habitat and host-related variables. Ticks were collected using the flagging method and mammal hosts were monitored using an innovative camera-trapping approach across 25 forest plots along a land-use gradient within the Schw&#xe4;bische Alb exploratory in Germany. Both tick density and Borrelia spp. prevalence are influenced by a complex combination of habitat factors across different spatial scales, as well as the mammal host community composition. Overall, our results provide novel support to the dilution effect hypothesis, suggesting that greater habitat and host diversity contribute to a reduced Lyme borreliosis risk in this region.

Animals