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The increase of emerging drug resistant Gram-negative bacterial infections is of global concern. In addition, there is growing recognition that compromising the microbiota, through the use of broad spectrum antibiotics, may affect patient health in the long term. Therefore, there is the need to develop new -cidal strategies to combat Gram-negative infections that would consider these specific issues. In this study, we report and characterize one such approach, the antibody-drug conjugates (ADCs) that combine (i) targeting a specific pathogenic organism through a monoclonal antibody with (ii) the high killing activity of antimicrobial peptides. We focused on a major pathogenic Gram-negative bacterium associated with antibacterial resistance:Pseudomonas aeruginosaand designed an ADC by fusing an antimicrobial peptide at the C-terminal end of the VHand/or VL-chain of a monoclonal antibody, VSX, that targets the core ofP. aeruginosalipopolysaccharide (LPS). This ADC demonstrated appropriately minimal levels of toxicity to mammalian cells and rapidly killsP. aeruginosastrains through several mechanisms while protecting mice fromP. aeruginosalung infection when administered therapeutically. Furthermore, we found that the ADC was synergistic with several classes of antibiotics. This approach described in this study may result in a widely useful strategy to target specific pathogenic microorganisms without augmenting further antibiotic resistance.Author SummaryThe increasing of emerging drug resistant bacterial infections is a worldwide issue and infections caused by antibiotic resistant Gram-negative pathogens are particularly concerning. In addition, there is now growing recognition that disruption of the microbiota, through the use of broad spectrum antibiotics, may affect patient health in the long term. Therefore, there is the need to develop new -cidal strategies to combat Gram-negative infections while preserving the microbiota and also avoid enhancement of antibiotic resistance. We report and characterize here one such approach by using a specific monoclonal antibody associated with the potent killing activity of antimicrobial peptides in the form of an antibody-drug conjugate (ADC). The selected pathogenic bacterium wasPseudomonas aeruginosa,that presents numerous markers for both innate and acquired antibiotic resistance. The ADC lacked significant cytotoxicity against mammalian cells and was shown to be effective bothin vitroandin vivoagainstP. aeruginosa.

Pediatric central nervous system (CNS) cancers are the leading disease-related cause of death in children and there is urgent need for curative therapeutic strategies for these tumors. To address the urgency, Children’s Brain Tumor Network (CBTN) has advanced an open science model to accelerate the research discovery for pediatric brain tumors. In first phase of Open Pediatric Brain Tumor Atlas (OpenPBTA) effort CBTN together with Pacific Pediatric Neuro-Oncology Consortium (PNOC) with support of Gabriella Miller Kids First Data Resource Center (KFDRC) created and comprehensively characterized over 1000 clinically annotated pediatric brain tumors. In the second phase of the OpenPBTA effort, through resource awards and collaboration across KFDRC, the NCI Childhood Cancer Data Initiative (CCDI), NCI’s Clinical Proteomic Tumor Analysis Consortium (CPTAC), NCI Center for Cancer Research and additional partnered institutions and foundations, CBTN has expanded OpenPBTA to support high throughput molecular characterization for an additional 1900 pediatric brain tumor patients and their families. This includes the processing and characterization of over 8000 specimens across >50 brain tumor diagnoses. The cohort expansion builds on >1000 previously characterized samples with a portfolio of multimodal data including whole genome sequencing, RNA sequencing, miRNA sequencing, methylation sequencing, proteomics, lipidomics and/or metabolomics. Molecular data is linked to patient longitudinal clinical data, imaging data (MRIs and radiology reports), histology slide images, and pathology reports. To inform novel discovery and clinical implementation of genomic approaches for diagnostic/therapeutic purposes, the data is deposited the cloud-based research environment of the NCI’s CCDI and the KFDRC to provide near real-time integration, dissemination, processing, and sharing of associated petabyte-scale harmonized data. The approach leverages the DRC platform’s cloud-based computational environment in CAVATICA. Processed annotations are facilitated via CAVATICA-enabled shareable pipelines and can be explored through PedcBioPortal, a data visualization/analysis application further integrating additional public and deposited datasets. This expansion phase of OpenPBTA is released with no embargo period and provides one of the largest deeply characterized cohorts of pediatric brain tumor samples and associated clinical data for >3000 pediatric brain tumor patients. CBTN’s open-science, rapid-release model aims to advance novel biomarkers and therapeutic exploratory research, supporting new clinical trial development and accelerated discovery on behalf of changing the outcome for kids with brain tumors. Citation Format: Mateusz P. Koptyra, Komal Rahti, Yuankun Zhu, Bailey Farrow, Daniel Miller, Adam Kraya, Yiran Guo, Peter Madsen, Nicholas Van Kuren, Xiaoyan Huang, Miguel A. Brown, Jennifer L. Mason, Meen Chul Kim, Allison P. Heath, Brian M. Ennis, Bo Zhang, Jena V. Lilly, Jo Lynne Rokita, Christopher Friedman, Ximena P. Cuellar, Catherine A. Sullivan, Noel Coleman, Trang Duros, Thinh Q. Nguyen, Emmett C. Drake, Zeinab Helili, Beth A. Frenkel, Gerri R. Trooskin, Ariana Familiar, Karthik Viswanathan, Christopher M. Beck, Madison L. Hollawell, Valerie P. Baubet, Cassie Kline, Mariarita Santi, Tatiana S. Patton, Stephanie Stefankiewicz, Arya Kamnaa, Ryan A. Velasco, Dani Cardona, Phillip J. Storm, Adam C. Resnick, o/b/o Children's Brain Tumor Network. Expansion of the Pediatric Brain Tumor Atlas: Children's Brain Tumor Network, Kids First Data Resource and Childhood Cancer Data Initiative Open Science effort. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3566.

Catastrophic hazards like landslides are generally associated with extreme hydraulic conditions. Western Ghats, India is characterized as one of the most landslide-prone areas in India, other than ...

Background Unlike T‐wave alternans (TWA), the relation between QRS alternans (QRSA) and ventricular arrhythmia (VA) risk has not been evaluated in hypertrophic cardiomyopathy (HCM). We assessed microvolt QRSA/TWA in relation to HCM risk factors and late VA outcomes in HCM. Methods and Results Prospectively enrolled patients with HCM (n=130) with prophylactic implantable cardioverter‐defibrillators underwent digital 12‐lead ECG recordings during ventricular pacing (100–120 beats/min). QRSA/TWA was quantified using the spectral method. Patients were categorized as QRSA+ and/or TWA+ if sustained alternans was present in ≥2 precordial leads. The VA end point was appropriate implantable cardioverter‐defibrillator therapy over 5 years of follow‐up. QRSA+ and TWA+ occurred together in 28% of patients and alone in 7% and 7% of patients, respectively. QRSA magnitude increased with pacing rate (1.9±0.6 versus 6.2±2.0 µV; P =0.006). Left ventricular thickness was greater in QRSA+ than in QRSA− patients (22±7 versus 20±6 mm; P =0.035). Over 5 years follow‐up, 17% of patients had VA. The annual VA rate was greater in QRSA+ versus QRSA− patients (5.8% versus 2.0%; P =0.006), with the QRSA+/TWA− subgroup having the greatest rate (13.3% versus 2.6%; P P =0.001). Separate Cox models revealed QRSA+ (hazard ratio [HR], 2.9 [95% CI, 1.2–7.0]; P =0.019) and QRSA+/TWA− (HR, 7.9 [95% CI, 2.9–21.7]; P Conclusions In HCM, microvolt QRSA is a novel, rate‐dependent phenomenon that can exist without TWA and is associated with greater left ventricular thickness. QRSA increases VA risk 3‐fold in all patients, whereas the absence of QRSA confers low VA risk in patients with Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02560844.

Background An integrated structured approach to atrial fibrillation (AF) management is recommended by ESC.1 However, limited data is available on its “real-world” impact on anticoagulation uptake and subsequent AF-related hospitalisation and stroke rates. Purpose To evaluate the long-term impact of the introduction of a community-wide integrated AF service based in a secondary care hospital. Methods In September 2017 we implemented a new integrated pathway for patients with newly diagnosed “symptomatic” atrial arrhythmias across two regions (population 450,000) in England in collaboration with primary care. All patients were seen in a one-stop multi-professional clinic (Arrhythmia nurse and Electrophysiologist with ECG and echocardiogram) within 2 weeks. They underwent standardised screening for modifiable risk factors, counselling regarding diagnosis/ anticoagulation and received an individualised AF management plan as well as access to a nurse-led telephone helpline. We followed up the first 126 consecutive patients for a period of 12 months. Results Baseline characteristics are shown in Table 1, showing a high incidence of modifiable risk factors (previously un-identified in the majority). After review in clinic, 30-day AF-related readmission rates to hospital were low (1.6%, n=2) as compared to historical local data (5.8%). This was sustained at 3 months (4.7%, n=6) and at 12 months (7.9%, n=10). 99% of 83 of eligible patients (CHA2DS2-VASc score of >2 with no major contra-indications) received oral anticoagulation. Over 12 months follow-up, rates of TIA/stroke was low (n=3, 2.4%). All-cause mortality was also low (n=1, 0.8%). NHS England region-wide data showed a marked reduction in percentage of total stroke admissions with history of AF not taking anticoagulation at stroke presentation in 2018/19 as compared to 2017/18 across our two regions; this was lower than the national average and the lowest within West Yorkshire (Figure 1). Conclusions An integrated service for AF management implemented community-wide was associated with high uptake of oral anticoagulation among eligible patients and low rates of AF-related hospitalisations and all-cause mortality. Across the community, among stroke admissions with AF at presentation, a lower percentage of patients without anticoagulation was observed in comparison with previous years and neighbouring regions. Funding Acknowledgement Type of funding sources: None.

Background An integrated structured approach to atrial fibrillation (AF) management is recommended by ESC.1 However, limited data is available on its ‘real-world’ impact on anticoagulation uptake and subsequent AF-related hospitalisation and stroke rates. Purpose To evaluate the long-term impact of the introduction of a community-wide integrated AF service based in a secondary care hospital. Methods In September 2017 we implemented a new integrated pathway for patients with newly diagnosed ‘symptomatic’ atrial arrhythmias across two regions (population 450,000) in England in collaboration with primary care. All patients were seen in a one-stop multi-professional clinic (Arrhythmia nurse and Electrophysiologist with ECG and echocardiogram) within 2 weeks. They underwent standardised screening for modifiable risk factors, counselling regarding diagnosis/ anticoagulation and received an individualised AF management plan as well as access to a nurse-led telephone helpline. We followed up the first 126 consecutive patients for a period of 12 months. Results Baseline characteristics are shown in table 1, showing a high incidence of modifiable risk factors (previously un-identified in the majority). After review in clinic, 30-day AF-related readmission rates to hospital were low (1.6%, n=2) as compared to historical local data (5.8%). This was sustained at 3 months (4.7%, n=6) and at 12 months (7.9%, n=10). 99% of 83 of eligible patients (CHA2DS2-VASc score of >2 with no major contra-indications) received oral anticoagulation. Over 12 months follow-up, rates of TIA/stroke was low (n=3, 2.4%). All-cause mortality was also low (n=1, 0.8%). NHS England region-wide data showed a marked reduction in percentage of total stroke admissions with history of AF not taking anticoagulation at stroke presentation in 2018/19 as compared to 2017/18 across our two regions; this was lower than the national average and the lowest within West Yorkshire (figure 1).2 Conclusions An integrated service for AF management implemented community-wide was associated with high uptake of oral anticoagulation among eligible patients and low rates of AF-related hospitalisations and all-cause mortality. Across the community, among stroke admissions with AF at presentation, a lower percentage of patients without anticoagulation was observed in comparison with previous years and neighbouring regions. Conflict of Interest none

Bacterial infections are a growing public health threat with carbapenem-resistant

Therapeutically targeting CD138, a define multiple myeloma (MM) antigen, is not yet approved for patients. We here developed and determined the preclinical efficacy of VIS832, a novel therapeutic monoclonal antibody (MoAb) with differentiated CD138 target binding to BB4 that is anti-CD138 MoAb scaffold for indatuximab ravtansine (BT062). VIS832 demonstrated enhanced CD138-binding avidity and significantly improved potency to kill MM cell lines and autologous patient MM cells regardless of resistance to current standard-of-care therapies, via robust antibody-dependent cellular cytotoxicity and phagocytosis mediated by NK and macrophage effector cells, respectively. Specifically, CD38-targeting daratumumab-resistant MM cells were highly susceptible to VIS832 which, unlike daratumumab, spares NK cells. Superior maximal cytolysis of VIS832 vs. daratumumab corresponded to higher CD138 vs. CD38 levels in MM cells. Furthermore, VIS832 acted synergistically with lenalidomide or bortezomib to deplete MM cells. Importantly, VIS832 at a sub-optimal dose inhibited disseminated MM1S tumors in vivo as monotherapy (P

To combat antimicrobial infections, new active molecules are needed. Antimicrobial peptides, ever abundant in nature, are a fertile starting point to develop new antimicrobial agents but suffer from low stability, low specificity, and off-target toxicity. These drawbacks have limited their development. To overcome some of these limitations, we developed antibody-bactericidal macrocyclic peptide conjugates (ABCs), in which the antibody directs the bioactive macrocyclic peptide to the targeted Gram-negative bacteria. We used cysteine SN Ar chemistry to synthesize and systematically study a library of large (>30-mer) macrocyclic antimicrobial peptides (mAMPs) to discover variants with extended proteolytic stability in human serum and low hemolytic activity while maintaining bioactivity. We then conjugated, by using sortase A, these bioactive variants onto an Escherichia coli targeted monoclonal antibody. We found that these ABCs had minimized hemolytic activity and were able to kill E. coli at nanomolar concentrations. Our findings suggest macrocyclic peptides if fused to antibodies may facilitate the discovery of new agents to treat bacterial infections.

Engineering of antibodies for improved pharmacokinetics through enhanced binding to the neonatal Fc receptor (FcRn) has been demonstrated in transgenic mice, non-human primates and humans. Traditionally, such approaches have largely relied on random mutagenesis and display formats, which fail to address related critical attributes of the antibody, such as effector functions or biophysical stability. We have developed a structure- and network-based framework to interrogate the engagement of IgG with multiple Fc receptors (FcRn, C1q, TRIM21, FcγRI, FcγRIIa/b, FcγRIIIa) simultaneously. Using this framework, we identified features that govern Fc-FcRn interactions and identified multiple distinct pathways for enhancing FcRn binding in a pH-specific manner. Network analysis provided a novel lens to study the allosteric impact of half-life-enhancing Fc mutations on FcγR engagement, which occurs distal to the FcRn binding site. Applying these principles, we engineered a panel of unique Fc variants that enhance FcRn binding while maintaining robust biophysical properties and wild type-like binding to activating receptors. An antibody harboring representative Fc designs demonstrates a half-life improvement of > 9 fold in transgenic mice and > 3.5 fold in cynomolgus monkeys, and maintains robust effector functions such as antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity.

Immunotherapeutically targeting CD138 has not been successfully translated into substantial clinical benefit in multiple myeloma (MM) patients. We here developed and determined in preclinical models of human MM the efficacy of VIS832, a novel humanized monoclonal antibody (MoAb) with differentiated CD138 target binding to the anti-CD138 MoAb BB4 within indatuximab ravtansine (BT082). Compared with BB4, VIS832 has significantly improved binding (P8). In the reporter-based antibody-dependent cellular cytotoxicity (ADCC) bioassay, EC50 of VIS832 was approximately 99.31 ng/ml (0.66 nM), whereas the BB4 possessing an isotype matched human IgG1 minimally induced ADCC against U266 MM cells. Evaluation of VIS832-induced ADCC in NK-MM cell co-cultures determined its EC50 values ranged from 2.22 + 0.37 to 15.3 + 2.71 ng/ml, with % maximal lysis of 37.06 + 1.45 % to 97.3 + 3.34 %, across tested MM cell lines (n=12), both sensitive or resistant to current therapies including dexamethasone, IMiDs, and bortezomib. While VIS832 effectively induced ADCC against parental cells with high and low CD138 levels, no lysis was detected in paired CD138-knockout MM cells. In the presence of BM stromal cells or osteoclasts, two key MM-supporting accessory cells in the BM milieu, VIS832-induced MM cytolysis was minimally affected. Importantly, VIS832 eliminated autologous MM cells of bone marrow (BM) samples from relapsed/refractory (RRMM) patients, with > 60% maximal lysis and > 90% killing in 4 out of 7 patient BM samples. EC50 values of VIS832 were 8.58-86.04 ng/ml in this patient cohort, comparable to those (17.28-179.3 ng/ml) of its non-humanized predecessor mAb 2810 against another RRMM patient cohort (n=6). In contrast to its potent autologous CD138+ patient cell lysis, VIS832 did not affect CD138-negative patient BM cells. VIS832 induced higher maximal lysis (~3-fold) of all target MM cell lines than CD38-targeting daratumumab (dara), regardless of resistance to lenalidomide and pomalidomide. These results also confirmed significantly higher CD138 vs CD38 levels in all MM cell lines and patient MM cells (P60 days (P Disclosures Chaganty: Visterra Inc: Current Employment. Ramakrishnan:Visterra Inc: Current Employment. Wollacott:Visterra Inc: Current Employment. Viswanathan:Visterra Inc: Current Employment. Adari:Visterra Inc: Current Employment. Munshi:Karyopharm: Consultancy; Amgen: Consultancy; Legend: Consultancy; Adaptive: Consultancy; Janssen: Consultancy; C4: Current equity holder in private company; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; BMS: Consultancy; Takeda: Consultancy; AbbVie: Consultancy. Babcock:Visterra Inc: Current Employment. Shriver:Visterra Inc: Current Employment. Myette:Visterra Inc: Current Employment. Anderson:Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Oncopep and C4 Therapeutics.: Other: Scientific Founder of Oncopep and C4 Therapeutics.; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees.

Road traffic injuries (RTIs) stands as one of the leading causes of mortality and morbidity across the globe. Effective injury surveillance systems and pre-hospital and in-hospital interventions set up in developing countries have shown promising results in controlling the problem. This study aimed to standardise and evaluate an evidence-based intervention for safety, efficacy and quality of post-crash pre-hospital and in-hospital trauma care services to improve the outcome in RTI victims. In addition, it establishes the android-based trauma registry for effective RTI surveillance. This multi-centric, prospective, observational study is commissioned by the Indian Council of Medical Research (ICMR) as a National Task Force Project. This study is being conducted in five sites, viz., Anand, Bengaluru, Delhi, Lucknow and Thrissur located across India. Each centre will have a level I, two level II and three level III trauma hospitals. The study will be carried out in four phases namely: i) preparatory phase, ii) trauma registry establishment and pre-intervention data collection, iii) intervention and iv) impact evaluation. The preparatory phase, which lasts for four months includes the situational analysis pertaining to managing RTIs. Trauma registry will be initiated from the fifth month. Pre-intervention data will be collected for six months. The intervention will be conducted for six months in the form of prehospital notification, training for trauma care providers and trauma care quality improvement. Post-intervention data collection will continue for 12 months and the impact of the intervention will be assessed. The primary outcome measure will be early preventable mortality, defined as death at 24 hours after admission for patients with a calculated probability of survival >50% based on their injury severity score.

Antibodies often undergo substantial engineering en route to the generation of a therapeutic candidate with good developability properties. Characterization of antibody libraries has shown that retaining native-like sequence improves the overall quality of the library. Motivated by recent advances in deep learning, we developed a bi-directional long short-term memory (LSTM) network model to make use of the large amount of available antibody sequence information, and use this model to quantify the nativeness of antibody sequences. The model scores sequences for their similarity to naturally occurring antibodies, which can be used as a consideration during design and engineering of libraries. We demonstrate the performance of this approach by training a model on human antibody sequences and show that our method outperforms other approaches at distinguishing human antibodies from those of other species. We show the applicability of this method for the evaluation of synthesized antibody libraries and humanization of mouse antibodies.

Background Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection. Methods We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA). Results Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%). Conclusions In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort.

Tectonic movements and vibrations of the earth cannot be controlled, which causes devastating natural hazards like landslides and earthquakes which have accounted for many lives in the previous years. The major reasons for landslides are heavy rainfall, liquefaction, rise in pore water pressure, floods, etc. This experimental study focuses on identifying the Critical Phreatic Level (CPL) of different soil types for different slope geometries. Different soil types were modeled in a tank of dimensions 2.30 × 1.00 × 1.25 m to simulate the natural field conditions like field density, ground water flow and slope angle in the laboratory with scaled down slopes of specific angles, based on the natural angle of repose of the soil. Density closely resembling the natural field density was obtained by air pluviation and a constant water inflow from an adjacent chamber was provided to simulate groundwater flow. The slope geometry was modeled, initial conditions were set and the phreatic level in the slope was continuously monitored until the slope fails with considerable slope displacement. The soil properties such as permeability, bulk unit weight, specific gravity and angle of repose obtained from laboratory tests were used as input parameters to model the slopes in PLAXIS 2D. The displacement values obtained from the software were compared with the displacement values obtained from the experiment, and were found to be similar, thereby validating the results.

Background— Substrate-based mapping for ventricular tachycardia (VT) ablation is hampered by its inability to determine critical sites of the VT circuit. We hypothesized that those potentials, which delay with a decremental extrastimulus (decrement evoked potentials or DEEPs), are more likely to colocalize with the diastolic pathways of VT circuits. Methods and Results— DEEPs were identified in intraoperative left ventricular maps from 6 patients with ischemic cardiomyopathy (total 9 VTs) and were compared with late potential (LP) and activation maps of the diastolic pathway for each VT. Mathematical modeling was also used to further validate and elucidate the mechanisms of DEEP mapping. All patients demonstrated regions of DEEPs and LPs. The mean endocardial surface area of these potentials was 18±4% and 21±6%, respectively ( P =0.13). The mean sensitivity for identifying the diastolic pathway in VT was 50±23% for DEEPs and 36±32% for LPs ( P =0.31). The mean specificity was 43±23% versus 20±8% for DEEP and LP mapping, respectively ( P =0.031). The electrograms that displayed the greatest decrement in each case had a sensitivity and specificity for the VT isthmus of 29±10% and 95±1%, respectively. Mathematical modeling studies recapitulated DEEPs at the VT isthmus and demonstrated their role in VT initiation with a critical degree of decrement. Conclusions— In this preliminary study, DEEP mapping was more specific than LP mapping for identifying the critical targets of VT ablation. The mechanism of DEEPs relates to conduction velocity restitution magnified by zigzag conduction within scar channels.

Dengue is the most common vector-borne viral disease, causing nearly 400 million infections yearly. Currently there are no approved therapies. Antibody epitopes that elicit weak humoral responses may not be accessible by conventional B cell panning methods. To demonstrate an alternative strategy to generating a therapeutic antibody, we employed a non-immunodominant, but functionally relevant, epitope in domain III of the E protein, and engineered by structure-guided methods an antibody directed to it. The resulting antibody, Ab513, exhibits high-affinity binding to, and broadly neutralizes, multiple genotypes within all four serotypes. To assess therapeutic relevance of Ab513, activity against important human clinical features of dengue was investigated. Ab513 mitigates thrombocytopenia in a humanized mouse model, resolves vascular leakage, reduces viremia to nearly undetectable levels, and protects mice in a maternal transfer model of lethal antibody-mediated enhancement. The results demonstrate that Ab513 may reduce the public health burden from dengue., National Institutes of Health (U.S.) (NIH Award (1R01AI111395)), National Institute of Environmental Health Sciences (NIEHS training grant (2T32ES007020)), National Institutes of Health (U.S.) (NIH Merit Award (R37 GM057073-13)), National Science Foundation (U.S.)

OBJECTIVES: The authors conducted a multicenter study of decrement-evoked potential (DEEP)-based functional ventricular tachycardia (VT) substrate modification to evaluate if such a mechanistic and physiological strategy is feasible and efficient in clinical practice and provides reduction in the VT burden.BACKGROUND: Only a fraction of the myocardium targeted in current VT substrate modification procedures is involved in the initiation and perpetuation of VT. The physiological basis of the DEEP strategy for identification of areas of initiation and maintenance of VT was recently established.METHODS: We included 20 consecutive patients with ischemic cardiomyopathy. During substrate mapping, fractionated and late potentials (LPs) were tagged, and an extra stimulus was performed to determine which LPs displayed decrement (DEEPs). All patients underwent DEEP-focused ablation: elimination of DEEP + further radiofrequency (RF) if VT was still inducible. Patients were followed during 6 months.RESULTS: Patients were predominantly male (95%), and their mean age was 64.6 ± 17.1 years. Mean left ventricular ejection fraction was 33.4 ± 11.4%. Mean ablation time was 30.6 ± 20.4 min. Specificity of DEEPs to detect the isthmus of VT was better than that of LPs (0.97 [95% confidence interval [CI]: 0.95 to 0.98] vs. 0.82 [95% CI: 0.73 to 0.89]), without significant differences in terms of sensitivity (0.61 [95% CI: 0.52 to 0.69] vs. 0.60 [95% CI: 0.44 to 0.74], respectively). Fifteen of 20 (75%) patients were free of any VT after DEEP-RF at 6 months of follow-up and there was a strong reduction in VT burden compared to 6 months pre-ablation.CONCLUSIONS: In a multicenter prospective study, DEEP substrate mapping identified the functional substrate critical to the VT circuit with high specificity. DEEP-guided VT ablation, by its physiological nature, may enable greater access to focused ablation therapy for patients requiring VT treatment.

IgA nephropathy (IgAN) is the most prevalent cause of primary glomerular disease worldwide, and the cytokine A PRoliferation-Inducing Ligand (APRIL) is emerging as a key player in IgAN pathogenesis and disease progression. For a panel of anti-human APRIL antibodies with known antagonistic activity, we sought to define their structural mode of engagement to understand molecular mechanisms of action and aid rational antibody engineering. Reliable computational prediction of antibody-antigen complexes remains challenging, and experimental methods such as X-ray co-crystallography and cryoEM have considerable technical, resource, and throughput barriers. To overcome these limitations, we implemented an integrated and accessible experimental-computational workflow to more accurately predict structures of antibody-APRIL complexes. Specifically, a yeast surface display library encoding site-saturation mutagenized surface positions of APRIL was screened against a panel of anti-APRIL antibodies to rapidly obtain a comprehensive biochemical profile of mutational impact on binding for each antibody. The experimentally derived mutational profile data were used as quantitative constraints in a computational docking workflow optimized for antibodies, resulting in robust structural models of antibody-antigen complexes. The model results were confirmed by solving the cocrystal structure of one antibody-APRIL complex, which revealed strong agreement with our model. The models were used to rationally select and engineer one antibody for cross-species APRIL binding, which quite often aids further testing in relevant animal models. Collectively, we demonstrate a rapid, integrated computational-experimental approach to robustly predict antibody-antigen structures information, which can aid rational antibody engineering and provide insights into molecular mechanisms of action.

Patients with coronary artery disease (CAD) can present with spontaneous ventricular arrhythmias occurring outside the context of an acute coronary syndrome with no apparent identifiable reversible cause. In addition to secondary prevention medications, implantable cardiac defibrillator (ICD) remains the main therapeutic intervention to reduce the risk of subsequent mortality and morbidity. Investigations prior to ICD implantation may identify the presence of angiographically significant epicardial coronary stenoses in previously asymptomatic patients, alongside other arrhythmic substrates such as myocardial scar and impaired left ventricular systolic function. So does coronary revascularisation in these patients reduce the occurrence of appropriate ICD shocks in the long run? In this article we comprehensively review the literature to answer the primary question of whether coronary revascularisation reduces recurrent ventricular arrhythmia burden among patients with CAD receiving an ICD, with focus on those presenting with ventricular arrhythmias outside the context of acute coronary syndrome. With growing evidence of the adverse prognostic impact of appropriate ICD discharges and an ever-increasing number of ICD implants world-wide, we believe that this question is of paramount importance. We summarise the available evidence to draw conclusions about the appropriate management strategy and also highlight areas of uncertainty that require attention in future research.

Summary Of the factors governing human-to-human transmission of the highly pathogenic avian-adapted H5N1 virus, the most critical is the acquisition of mutations on the viral hemagglutinin (HA) to "quantitatively switch" its binding from avian to human glycan receptors. Here, we describe a structural framework that outlines a necessary set of H5 HA receptor-binding site (RBS) features required for the H5 HA to quantitatively switch its preference to human receptors. We show here that the same RBS HA mutations that lead to aerosol transmission of A/Vietnam/1203/04 and A/Indonesia/5/05 viruses, when introduced in currently circulating H5N1, do not lead to a quantitative switch in receptor preference. We demonstrate that HAs from circulating clades require as few as a single base pair mutation to quantitatively switch their binding to human receptors. The mutations identified by this study can be used to monitor the emergence of strains having human-to-human transmission potential.

Influenza is a severe disease in humans and animals with few effective therapies available. All strains of influenza virus are prone to developing drug resistance due to the high mutation rate in the viral genome. A therapeutic agent that targets a highly conserved region of the virus could bypass resistance and also be effective against multiple strains of influenza. Influenza uses many individually weak ligand binding interactions for a high avidity multivalent attachment to sialic acid-bearing cells. Polymerized sialic acid analogs can form multivalent interactions with influenza but are not ideal therapeutics due to solubility and toxicity issues. We used liposomes as a novel means for delivery of the glycan sialylneolacto-N-tetraose c (LSTc). LSTc-bearing decoy liposomes form multivalent, polymer-like interactions with influenza virus. Decoy liposomes competitively bind influenza virus in hemagglutination inhibition assays and inhibit infection of target cells in a dose-dependent manner. Inhibition is specific for influenza virus, as inhibition of Sendai virus and respiratory syncytial virus is not observed. In contrast, monovalent LSTc does not bind influenza virus or inhibit infectivity. LSTc decoy liposomes prevent the spread of influenza virus during multiple rounds of replication in vitro and extend survival of mice challenged with a lethal dose of virus. LSTc decoy liposomes co-localize with fluorescently tagged influenza virus, whereas control liposomes do not. Considering the conservation of the hemagglutinin binding pocket and the ability of decoy liposomes to form high avidity interactions with influenza hemagglutinin, our decoy liposomes have potential as a new therapeutic agent against emerging influenza strains.

Background— Cardiomyopathy patients are at risk of sudden death, typically from scar-related abnormalities of electrical activation that promote ventricular tachyarrhythmias. Abnormal intra-QRS peaks may provide a measure of altered activation. We hypothesized that quantification of such QRS peaks (QRSp) in high-resolution ECGs would predict arrhythmic events in implantable cardioverter–defibrillator (ICD)–eligible cardiomyopathy patients. Methods and Results— Ninety-nine patients with ischemic or non-ischemic dilated cardiomyopathy undergoing prophylactic ICD implantation were prospectively enrolled (age 62±11 years, left ventricular ejection fraction 27±7%). High-resolution (1024 Hz) digital 12-lead ECGs were recorded during intrinsic rhythm. QRSp was quantified for each precordial lead as the total number of low-amplitude deflections that deviated from their respective naive QRS template. The primary end point of arrhythmic events was defined as appropriate ICD therapy or sustained ventricular tachyarrhythmias. After a median follow-up of 24 (15–43) months, 20 (20%) patients had arrhythmic events. Both QRSp and QRS duration were greater in those with arrhythmic events (both P P P P Conclusions— QRSp measured from high-resolution digital 12-lead ECGs independently predicts ventricular tachyarrhythmias in ICD-eligible cardiomyopathy patients. This novel QRS morphology index has the potential to improve sudden death risk stratification and patient selection for prophylactic ICD therapy.