Activating FcγRs on monocytes are necessary for optimal Mayaro virus clearance.

Mayaro virus (MAYV) is an emerging arbovirus. Previous studies have shown antibody Fc effector functions are critical for optimal monoclonal antibody-mediated protection against alphaviruses; however, the requirement of Fc gamma receptors (FcγRs) for protection during natural infection has not been evaluated. Here, we showed mice lacking activating FcγRs (FcRγ -/- ) developed prolonged clinical disease with more virus in joint-associated tissues. Viral clearance was associated with anti-MAYV cell surface binding rather than neutralizing antibodies. Lack of Fc-FcγR engagement increased the number of monocytes through chronic timepoints. Single cell RNA sequencing showed elevated levels of pro-inflammatory monocytes in joint-associated tissue with increased MAYV RNA present in FcRγ -/- monocytes and macrophages. Transfer of FcRγ -/- monocytes into wild type animals was sufficient to increase virus in joint-associated tissue. Overall, this study suggests that engagement of antibody Fc with activating FcγRs promotes protective responses during MAYV infection and prevents monocytes from being potential targets of infection.

Structure and dynamics of enterovirus genotype networks.

Like all biological populations, viral populations exist as networks of genotypes connected through mutation. Mapping the topology of these networks and quantifying population dynamics across them is crucial to understanding how populations adapt to changes in their selective environment. The influence of mutational networks is especially profound in viral populations that rapidly explore their mutational neighborhoods via high mutation rates. Using a single-cell sequencing method, scRNA-seq-enabled acquisition of mRNA and consensus haplotypes linking individual genotypes and host transcriptomes (SEARCHLIGHT), we captured and assembled viral haplotypes from hundreds of individual infected cells, revealing the complexity of viral population structures. We obtained these genotypes in parallel with host cell transcriptome information, enabling us to link host cell transcriptional phenotypes to the genetic structures underlying virus adaptation. Our examination of these structures reveals the common evolutionary dynamics of enterovirus populations and illustrates how viral populations reach through mutational "tunnels" to span evolutionary landscapes and maintain connection with multiple adaptive genotypes simultaneously.

C1q enables influenza hemagglutinin stem binding antibodies to block viral attachment and broadens the antibody escape repertoire.

Antigenic drift, the gradual accumulation of amino acid substitutions in the influenza virus hemagglutinin (HA) receptor protein, enables viral immune evasion. Antibodies (Abs) specific for the drift-resistant HA stem region are a promising universal influenza vaccine target. Although anti-stem Abs are not believed to block viral attachment, here we show that complement component 1q (C1q), a 460-kilodalton protein with six Ab Fc-binding domains, confers attachment inhibition to anti-stem Abs and enhances their fusion and neuraminidase inhibition. As a result, virus neutralization activity in vitro is boosted up to 30-fold, and in vivo protection from influenza PR8 infection in mice is enhanced. These effects reflect increased steric hindrance and not increased Ab avidity. C1q greatly expands the anti-stem Ab viral escape repertoire to include residues throughout the HA, some of which cause antigenic alterations in the globular region or modulate HA receptor avidity. We also show that C1q enhances the neutralization activity of non-receptor binding domain anti-SARS-CoV-2 spike Abs, an effect dependent on spike density on the virion surface. These findings demonstrate that C1q can greatly expand Ab function and thereby contribute to viral evolution and immune escape.

Uncovering Structural Plasticity of Enterovirus A through Deep Insertional and Deletional Scanning.

Insertions and deletions (InDels) are essential sources of novelty in protein evolution. In RNA viruses, InDels cause dramatic phenotypic changes contributing to the emergence of viruses with altered immune profiles and host engagement. This work aimed to expand our current understanding of viral evolution and explore the mutational tolerance of RNA viruses to InDels, focusing on Enterovirus A71 (EV-A71) as a prototype for Enterovirus A species (EV-A). Using newly described deep InDel scanning approaches, we engineered approximately 45,000 insertions and 6,000 deletions at every site across the viral proteome, quantifying their effects on viral fitness. As a general trend, most InDels were lethal to the virus. However, our screen reproducibly identified a set of InDel-tolerant regions, demonstrating our ability to comprehensively map tolerance to these mutations. Tolerant sites highlighted structurally flexible and mutationally plastic regions of viral proteins that avoid core structural and functional elements. Phylogenetic analysis on EV-A species infecting diverse mammalian hosts revealed that the experimentally-identified hotspots overlapped with sites of InDels across the EV-A species, suggesting structural plasticity at these sites is an important function for InDels in EV speciation. Our work reveals the fitness effects of InDels across EV-A71, identifying regions of evolutionary capacity that require further monitoring, which could guide the development of Enterovirus vaccines.

Widespread and dynamic expression of granzyme C by skin-resident antiviral T cells.

After recognition of cognate antigen (Ag), effector CD8+ T cells secrete serine proteases called granzymes in conjunction with perforin, allowing granzymes to enter and kill target cells. While the roles for some granzymes during antiviral immune responses are well characterized, the function of others, such as granzyme C and its human ortholog granzyme H, is still unclear. Granzyme C is constitutively expressed by mature, cytolytic innate lymphoid 1 cells (ILC1s). Whether other antiviral effector cells also produce granzyme C and whether it is continually expressed or responsive to the environment is unknown. To explore this, we analyzed granzyme C expression in different murine skin-resident antiviral lymphocytes. At steady-state, dendritic epidermal T cells (DETCs) expressed granzyme C while dermal γδ T cells did not. CD8+ tissue-resident memory T cells (TRM) generated in response to cutaneous viral infection with the poxvirus vaccinia virus (VACV) also expressed granzyme C. Both DETCs and virus-specific CD8+ TRM upregulated granzyme C upon local VACV infection. Continual Ag exposure was not required for maintained TRM expression of granzyme C, although re-encounter with cognate Ag boosted expression. Additionally, IL-15 treatment increased granzyme C expression in both DETCs and TRM. Together, our data demonstrate that granzyme C is widely expressed by antiviral T cells in the skin and that expression is responsive to both environmental stimuli and TCR engagement. These data suggest that granzyme C may have functions other than killing in tissue-resident lymphocytes.

High-resolution mapping reveals the mechanism and contribution of genome insertions and deletions to RNA virus evolution.

RNA viruses rapidly adapt to selective conditions due to the high intrinsic mutation rates of their RNA-dependent RNA polymerases (RdRps). Insertions and deletions (indels) in viral genomes are major contributors to both deleterious mutational load and evolutionary novelty, but remain understudied. To characterize the mechanistic details of their formation and evolutionary dynamics during infection, we developed a hybrid experimental-bioinformatic approach. This approach, called MultiMatch, extracts insertions and deletions from ultradeep sequencing experiments, including those occurring at extremely low frequencies, allowing us to map their genomic distribution and quantify the rates at which they occur. Mapping indel mutations in adapting poliovirus and dengue virus populations, we determine the rates of indel generation and identify mechanistic and functional constraints shaping indel diversity. Using poliovirus RdRp variants of distinct fidelity and genome recombination rates, we demonstrate tradeoffs between fidelity and Indel generation. Additionally, we show that maintaining translation frame and viral RNA structures constrain the Indel landscape and that, due to these significant fitness effects, Indels exert a significant deleterious load on adapting viral populations. Conversely, we uncover positively selected Indels that modulate RNA structure, generate protein variants, and produce defective interfering genomes in viral populations. Together, our analyses establish the kinetic and mechanistic tradeoffs between misincorporation, recombination, and Indel rates and reveal functional principles defining the central role of Indels in virus evolution, emergence, and the regulation of viral infection.

Sleeve gastrectomy facilitates weight loss and permits cardiac transplantation in patients with severe obesity and a left ventricular assist device (LVAD).

INTRODUCTION: Patients suffering from advanced heart failure may undergo left ventricular assist device (LVAD) placement as a bridge to cardiac transplantation. However, those with a BMI above 35 kg/m2 are generally not considered eligible for transplant due to their elevated cardiac risk. We review our experience with bariatric surgery in this high-risk population to assess its safety and efficacy in reducing BMI to permit cardiac transplantation. METHODS: We retrospectively reviewed all patients on durable LVAD support who underwent sleeve gastrectomy (SG) at Mount Sinai Hospital between August 2018 and December 2022. Electronic medical records were reviewed to analyze patient demographics, surgical details, and outcomes regarding weight loss and heart transplantation. RESULTS: We identified twelve LVAD patients who underwent SG. Three were performed laparoscopically and 9 via robotic approach. Four patients (33.3%) underwent an orthotopic heart transplant (OHTx). Half of these patients were female. For patients who underwent OHTx, mean age at LVAD placement was 41.0 (R30.6-52.2), at SG was 43.9 (R32.7-55.0) and at OHTx was 45.3 years (R33.3-56.8). Mean BMI increased from 38.8 at LVAD placement to 42.5 prior to SG. Mean time from SG to OHTx was 17.9 months (R6-7-27.5) during which BMI decreased to mean 32.8 at the time of OHTx. At most recent follow-up, mean BMI was 31.9. All patients were anticoagulated prior to surgery; one required return to the operating room on post-operative day 1 after SG for bleeding and one was re-admitted on post-operative day 7 for hematochezia treated conservatively. CONCLUSION: SG is a safe and effective operation in patients with severe obesity and heart failure requiring an LVAD. 66.7% of our cohort achieved target BMI < 35 and 33.3% underwent heart transplantation. Longer term follow-up is needed to clarify full bridge-to-transplant rate and long-term survival outcomes.

Nuclear and cytoplasmic spatial protein quality control is coordinated by nuclear-vacuolar junctions and perinuclear ESCRT.

Effective protein quality control (PQC), essential for cellular health, relies on spatial sequestration of misfolded proteins into defined inclusions. Here we reveal the coordination of nuclear and cytoplasmic spatial PQC. Cytoplasmic misfolded proteins concentrate in a cytoplasmic juxtanuclear quality control compartment, while nuclear misfolded proteins sequester into an intranuclear quality control compartment (INQ). Particle tracking reveals that INQ and the juxtanuclear quality control compartment converge to face each other across the nuclear envelope at a site proximal to the nuclear-vacuolar junction marked by perinuclear ESCRT-II/III protein Chm7. Strikingly, convergence at nuclear-vacuolar junction contacts facilitates VPS4-dependent vacuolar clearance of misfolded cytoplasmic and nuclear proteins, the latter entailing extrusion of nuclear INQ into the vacuole. Finding that nuclear-vacuolar contact sites are cellular hubs of spatial PQC to facilitate vacuolar clearance of nuclear and cytoplasmic inclusions highlights the role of cellular architecture in proteostasis maintenance.

Risk factors for acute ankle sprains in field-based, team contact sports: a systematic review of prospective etiological studies.

OBJECTIVE: The aim of this systematic review was to identify prospectively measured ankle sprain risk factors in field-based team contact sports. METHODS: Eight databases including SPORTDiscus, CINAHL Complete, MEDLINE (EBSCO), Education Source, Web of Science, Scopus, Embase, and Pubmed were searched using specific Boolean terms. A modified-CASP diagnostic test assessed the quality of the included studies. Extensive data extraction included but was not limited to injury definition, protocols for injury diagnosis and recording, and outcomes associated with ankle sprain. RESULTS: 4012 records were returned from the online search and 17 studies met the inclusion criteria for this review. Twelve different risk factors including anatomic alignment of the foot and ankle, joint laxity, height, mass, BMI (body mass index), age, ankle strength, hip strength, single leg landing performance (ground reaction force, pelvic internal rotation, and knee varus), and single leg reach were all found to be associated with ankle sprain incidence. Injury definitions and methods of diagnosis and recording varied across the 17 studies. CONCLUSION: This review updates the literature on prospective risk factors for ankle sprain in a specific population rather than heterogeneous cohorts previously studied. From more than 20 categories of risk factors investigated for ankle sprain association across 17 studies in field-based team contact sports, 12 variables were found to be associated with increased incidence of ankle sprain. In order to reduce the risk of ankle sprain, BMI, ankle plantar and dorsiflexion strength, hip strength, and single leg landing performance should be factored in to athlete assessment and subsequent program design. More studies utilizing standardized definitions and methods of recording and reporting are needed. Future prospective etiological studies will allow strength and conditioning coaches, physiotherapists, and physicians to apply specific training principles to reduce the risk and occurrence of ankle sprain injuries.

Interferon partly dictates a divergent transcriptional response in poxvirus-infected and bystander inflammatory monocytes.

Inflammatory monocytes (iMOs) and B cells are the main targets of the poxvirus ectromelia virus (ECTV) in the lymph nodes of mice and play distinct roles in surviving the infection. Infected and bystander iMOs control ECTV's systemic spread, preventing early death, while B cells make antibodies that eliminate ECTV. Our work demonstrates that within an infected animal that survives ECTV infection, intrinsic and bystander infection of iMOs and B cells differentially control the transcription of genes important for immune cell function and, perhaps, cell identity. Bystander cells upregulate metabolism, antigen presentation, and interferon-stimulated genes. Infected cells downregulate many cell-type-specific genes and upregulate transcripts typical of non-immune cells. Bystander (Bys) and infected (Inf) iMOs non-redundantly contribute to the cytokine milieu and the interferon response. Furthermore, we uncover how type I interferon (IFN-I) or IFN-γ signaling differentially regulates immune pathways in Inf and Bys iMOs and that, at steady state, IFN-I primes iMOs for rapid IFN-I production and antigen presentation.

Pediatric Facility Recognition Program and the Illinois EMSC Experience.

Emergency medical services (EMS) systems were initially developed in the United States during the late 1960s. Modeled from military experiences, EMS demonstrated that survival for prehospital patients could be improved with enhanced field triage, treatment, and transport protocols. Over the next few decades, it was identified that children and adolescents had poorer outcomes in similar acute medical situations as compared to adults. To address this, the emergency medical services for children (EMSC) program was established in 1985 as a federal initiative to ensure appropriate resources and adequately trained personnel are available to meet the emergency care needs of children who are critically ill and injured. In 1994, the Illinois EMSC program was established and a pediatric facility recognition program to improve the emergency care of pediatric patients was rolled out in 1998. This article reviews the development of EMSC facility recognition programs and discusses their unique characteristics and contributions to improved pediatric emergency care. [Pediatr Ann. 2021;50(4):e165-e171.].

Principles of dengue virus evolvability derived from genotype-fitness maps in human and mosquito cells.

Dengue virus (DENV) cycles between mosquito and mammalian hosts. To examine how DENV populations adapt to these different host environments, we used serial passage in human and mosquito cell lines and estimated fitness effects for all single-nucleotide variants in these populations using ultra-deep sequencing. This allowed us to determine the contributions of beneficial and deleterious mutations to the collective fitness of the population. Our analysis revealed that the continuous influx of a large burden of deleterious mutations counterbalances the effect of rare, host-specific beneficial mutations to shape the path of adaptation. Beneficial mutations preferentially map to intrinsically disordered domains in the viral proteome and cluster to defined regions in the genome. These phenotypically redundant adaptive alleles may facilitate host-specific DENV adaptation. Importantly, the evolutionary constraints described in our simple system mirror trends observed across DENV and Zika strains, indicating it recapitulates key biophysical and biological constraints shaping long-term viral evolution.

Viruses are constantly evolving as a result of mutations in their genetic material and environmental pressures. Viruses switching between insects and mammals face unique evolutionary pressures because they must retain their ability to infect both types of organisms. Yet, the mutations in a virus that may be beneficial in an insect may be different from the ones that may be beneficial in a mammal. Mutations in one host may be even harmful in the other. To learn more about how such viruses thrive as they switch between hosts, Dolan, Taguwa et al. studied the dengue virus, which causes over 390 million infections and over 10,000 deaths each year around the globe. They compared the mutations that occurred as the virus multiplied in human and mosquito cells grown in a laboratory. In the experiments, they used a method called ultra-deep RNA sequencing to identify every change that occurred in the genetic material of the virus each time it multiplied. They determined whether the mutations were beneficial or harmful based on whether they became more common ­ suggesting they helped the virus survive ­ or whether they did not persist because they were likely harmful or even fatal to the virus. The experiments showed that many harmful mutations constantly occur in the virus, in both human and mosquito cells. Beneficial changes happen rarely, and those that do are usually only helpful in one type of cell. Fatal mutations tended to occur in parts of the genetic material that encodes regions in the viral proteins that must remain the same. These structural elements appear to be essential to the virus's survival and unable to undergo change, which makes them good targets for antiviral drugs or vaccines. The techniques used in the study may be useful for investigating other viruses and for understanding the evolutionary constraints on viruses more generally. This may help scientists develop antiviral drugs or vaccines that will remain effective even as viruses continue to evolve and mutate.

Colonic Stents as a Bridge to Surgery Compared with Immediate Resection in Patients with Malignant Large Bowel Obstruction in a NY State Database.

BACKGROUND: There is controversy surrounding the efficacy and safety of colonic stents as a bridge to surgery compared with immediate resection in patients presenting with an acute malignant large bowel obstruction. METHODS: Retrospective longitudinal cohort study using the NYS SPARCS Database. Patients with acute malignant large bowel obstruction who either had stent followed by elective surgery within 3 weeks (bridge to surgery) or underwent immediate resection between October 2009 and June 2016 in the state of New York were included. The primary outcome was rate of stoma creation at index resection. Secondary outcomes were 90-day readmission, reoperation, procedural complications, and discharge disposition. RESULTS: A total of 3059 patients were included, n = 2917 (95.4%) underwent an immediate resection and n = 142 (4.6%) underwent bridge to surgery. We analyzed 139 patients in propensity score-matched groups. Patients in the bridge to surgery group were less likely than those in the immediate resection group to get a stoma at the time of surgery (OR 0.33, 95% CI 0.18-0.60). They were also less likely to be discharged to a rehabilitation facility or require a home health aide upon discharge (OR 0.36, 95% CI 0.22-0.61). There were no differences in rates of 90-day readmission, reoperation, or procedural complications between groups. DISCUSSION: Colonic stenting as a bridge to surgery leads to less stoma creation, a significant quality of life advantage, compared with immediate resection. Patients should be counseled regarding these potential benefits when the technology is available.

Robotic-assisted approaches to GERD following sleeve gastrectomy.

BACKGROUND: Sleeve gastrectomy (SG) is the most common bariatric operation in the United States but increases the incidence of gastroesophageal reflux disease (GERD). The aim of our study was to describe our experience with robotic-assisted management of intractable GERD after SG. METHODS: A systematic review of a prospectively maintained database was performed of consecutive patients undergoing robotic-assisted magnetic sphincter augmentation placement after sleeve gastrectomy (MSA-S group) or conversion to Roux-en-Y gastric bypass (RYGB group) for GERD from 2015 to 2019 at our tertiary- care bariatric center. These were compared to a consecutive group of patients undergoing robotic-assisted magnetic sphincter augmentation placement (MSA group) for GERD without a history of bariatric surgery from 2016 to 2019. The primary outcome was perioperative morbidity. Secondary outcomes were operative time (OT), 90-day re-intervention rate, length of stay, symptom resolution and weight change. RESULTS: There were 51 patients included in this study; 18 patients in the MSA group, 13 patients in the MSA-S group, and 20 patients in the RYGB group. There was no significant difference in age, gender, ASA score, preoperative endoscopic findings, or DeMeester scores (P > 0.05). BMI was significantly higher in patients undergoing RYGB compared to MSA or MSA-S (P < 0.0001). There were significant differences in OT between the MSA and RYGB groups (P < 0.0001) and MSA-S and RYGB groups (P = 0.009), but not MSA group to MSA-S group (P = 0.51). There was no significant difference in intraoperative and postoperative morbidity (P = 1.0 and P = 0.60, respectively). 30-day morbidity: 5.6% (MSA), 15.4% (MSA-S) and 15% (RYGB). There was no difference on PPI discontinuation among groups, with more than 80% success rate in all. CONCLUSIONS: The use of the robotic platform in the different approaches available for treatment of GERD after SG appears to be a feasible option with low morbidity and high success rate. Further data is needed to support our findings.

Abnormal Vital Sign Recognition and Provider Notification in the Pediatric Emergency Department.

INTRODUCTION: Vital signs measurements aid in the early identification of patients at risk of clinical deterioration and determining the severity of illness. Health care providers rely on registered nurses to document vital signs and communicate abnormalities. The purpose of this project was to improve the provider notification process regarding abnormal vital signs in a pediatric emergency department. METHOD: A best practice advisory (BPA) was piloted by the advanced practice providers in the pediatric emergency department. To evaluate the effects of the BPA, a mixed-methods study was employed. RESULTS: Implementation of the BPA improved the provider notification process and enhanced clinical decision making. The percentage of patients discharged home with abnormal respiratory rates (10.9% vs. 5.9%, p = .31), abnormal temperatures (15.6% vs. 7.5%, p = .14), and abnormal heart rates (25% vs. 11.9%, p = .11) improved. DISCUSSION: Creation and implementation of the BPA improved the abnormal vital sign communication process to providers at this single institution.

Engineering the Live-Attenuated Polio Vaccine to Prevent Reversion to Virulence.

The live-attenuated oral poliovirus vaccine (OPV or Sabin vaccine) replicates in gut-associated tissues, eliciting mucosa and systemic immunity. OPV protects from disease and limits poliovirus spread. Accordingly, vaccination with OPV is the primary strategy used to end the circulation of all polioviruses. However, the ability of OPV to regain replication fitness and establish new epidemics represents a significant risk of polio re-emergence should immunization cease. Here, we report the development of a poliovirus type 2 vaccine strain (nOPV2) that is genetically more stable and less likely to regain virulence than the original Sabin2 strain. We introduced modifications within at the 5' untranslated region of the Sabin2 genome to stabilize attenuation determinants, 2C coding region to prevent recombination, and 3D polymerase to limit viral adaptability. Prior work established that nOPV2 is immunogenic in preclinical and clinical studies, and thus may enable complete poliovirus eradication.

Differentiation Drives Widespread Rewiring of the Neural Stem Cell Chaperone Network.

Neural stem and progenitor cells (NSPCs) are critical for continued cellular replacement in the adult brain. Lifelong maintenance of a functional NSPC pool necessitates stringent mechanisms to preserve a pristine proteome. We find that the NSPC chaperone network robustly maintains misfolded protein solubility and stress resilience through high levels of the ATP-dependent chaperonin TRiC/CCT. Strikingly, NSPC differentiation rewires the cellular chaperone network, reducing TRiC/CCT levels and inducing those of the ATP-independent small heat shock proteins (sHSPs). This switches the proteostasis strategy in neural progeny cells to promote sequestration of misfolded proteins into protective inclusions. The chaperone network of NSPCs is more effective than that of differentiated cells, leading to improved management of proteotoxic stress and amyloidogenic proteins. However, NSPC proteostasis is impaired by brain aging. The less efficient chaperone network of differentiated neural progeny may contribute to their enhanced susceptibility to neurodegenerative diseases characterized by aberrant protein misfolding and aggregation.

National prospective cohort study describing how financial stresses are associated with attrition from surgical residency.

BACKGROUND: Attrition from general surgery residency is high with a national rate of 20%. We evaluated potential associations between financial considerations and attrition. METHODS: National prospective cohort study of categorical general surgery trainees. RESULTS: Of the 1048 interns who started training in 2007, 681 (65%) had complete survey and follow-up data. In logistic regression, those with higher starting attending salary expectations (>$300K) were more likely to leave training (OR 2.9, 95% CI 1.2-6.9). Women with a partner who earned more (>$50K/year) were more likely to leave training (OR 4.1, 95% CI 1.6-10.5). In a subgroup of interns undecided about their future practice setting (academic, community, private practice, industry), those with less debt (≤$100K) were more likely to leave training (OR 2.4, 95% CI 1.1-5.2). CONCLUSIONS: Several financial matters were associated with attrition. Addressing these financial concerns may help decrease attrition in surgical training and improve surgical training.