Stimulation of Potent Humoral and Cellular Immunity via Synthetic Dual-Antigen MVA-Based COVID-19 Vaccine COH04S1 in Cancer Patients Post Hematopoietic Cell Transplantation and Cellular Therapy.

Hematopoietic cell transplantation (HCT) and chimeric antigen receptor (CAR)-T cell patients are immunocompromised, remain at high risk following SARS-CoV-2 infection, and are less likely than immunocompetent individuals to respond to vaccination. As part of the safety lead-in portion of a phase 2 clinical trial in patients post HCT/CAR-T for hematological malignancies (HM), we tested the immunogenicity of the synthetic modified vaccinia Ankara-based COVID-19 vaccine COH04S1 co-expressing spike (S) and nucleocapsid (N) antigens. Thirteen patients were vaccinated 3-12 months post HCT/CAR-T with two to four doses of COH04S1. SARS-CoV-2 antigen-specific humoral and cellular immune responses, including neutralizing antibodies to ancestral virus and variants of concern (VOC), were measured up to six months post vaccination and compared to immune responses in historical cohorts of naïve healthy volunteers (HV) vaccinated with COH04S1 and naïve healthcare workers (HCW) vaccinated with the FDA-approved mRNA vaccine Comirnaty® (Pfizer, New York, NY, USA). After one or two COH04S1 vaccine doses, HCT/CAR-T recipients showed a significant increase in S- and N-specific binding antibody titers and neutralizing antibodies with potent activity against SARS-CoV-2 ancestral virus and VOC, including the highly immune evasive Omicron XBB.1.5 variant. Furthermore, vaccination with COH04S1 resulted in a significant increase in S- and N-specific T cells, predominantly CD4+ T lymphocytes. Elevated S- and N-specific immune responses continued to persist at six months post vaccination. Furthermore, both humoral and cellular immune responses in COH04S1-vaccinated HCT/CAR-T patients were superior or comparable to those measured in COH04S1-vaccinated HV or Comirnaty®-vaccinated HCW. These results demonstrate robust stimulation of SARS-CoV-2 S- and N-specific immune responses including cross-reactive neutralizing antibodies by COH04S1 in HM patients post HCT/CAR-T, supporting further testing of COH04S1 in immunocompromised populations.

Relationships Between Perceived Importance of Chaplain Presence and Health Professionals' Emotional Well-Being in the United States.

Hospital-based chaplains receive specialized training to provide spiritual support to patients and healthcare staff during difficult health transitions. However, the impact of perceived chaplain importance on healthcare staff's emotional and professional well-being is unclear. Healthcare staff (n = 1471) caring for patients in an acute care setting within a large health system answered demographic and emotional health questions in Research Electronic Data Capture (REDCap). Findings suggest that as perceived levels of chaplain importance increase, burnout may decrease and compassion satisfaction may improve. Chaplain presence in the hospital setting may support healthcare staff emotional and professional well-being following occupational stressors including COVID-19-related surges.

Dynamic states of eIF6 and SDS variants modulate interactions with uL14 of the 60S ribosomal subunit.

Assembly of ribosomal subunits into active ribosomal complexes is integral to protein synthesis. Release of eIF6 from the 60S ribosomal subunit primes 60S to associate with the 40S subunit and engage in translation. The dynamics of eIF6 interaction with the uL14 (RPL23) interface of 60S and its perturbation by somatic mutations acquired in Shwachman-Diamond Syndrome (SDS) is yet to be clearly understood. Here, by using a modified strategy to obtain high yields of recombinant human eIF6 we have uncovered the critical interface entailing eight key residues in the C-tail of uL14 that is essential for physical interactions between 60S and eIF6. Disruption of the complementary binding interface by conformational changes in eIF6 disease variants provide a mechanism for weakened interactions of variants with the 60S. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) analyses uncovered dynamic configurational rearrangements in eIF6 induced by binding to uL14 and exposed an allosteric interface regulated by the C-tail of eIF6. Disrupting key residues in the eIF6-60S binding interface markedly limits proliferation of cancer cells, which highlights the significance of therapeutically targeting this interface. Establishing these key interfaces thus provide a therapeutic framework for targeting eIF6 in cancers and SDS.

Achievement of age-friendly health systems committed to care excellence designation in a convenient care health care system.

OBJECTIVE: To describe the implementation of the age-friendly health systems (AFHS) 4Ms Framework, an evidence-based framework to assess and act on "What Matters, Medication, Mentation and Mobility to deliver Age-Friendly health care for patients 65 and older", to achieve the Institute for Health care Improvement (IHI) Committed to Care Excellence recognition in a convenient care health system and test two novel implementation strategies. SETTING: The study was conducted in over 1100 convenient care clinics in 35 states and DC. MinuteClinics are located in community-based retail pharmacies in rural, suburban, and urban areas and staffed with approximately 3300 nurse practitioners and physician associates. DESIGN: In Year 1, the project used a quality improvement design, and in Year 2, a quasi-experimental implementation research design to pilot two strategies at the provider level (Virtual Clinic and Plan-Do-Study-Act (PDSA)). Statistical process control charts were used to assess changes in 4Ms documentation over time. Mixed-effects Poisson regression was used to assess the effectiveness of the pilot studies. DATA COLLECTION: The electronic health record (EHR) was enhanced to capture documentation of the AFHS 4Ms assessments and actions. A learning platform was created to teach and evaluate provider 4Ms competency, and the two data sources were merged into a registry. A formative evaluation was conducted using Tableau and reporting dashboards. FINDINGS: After 18 months and the implementation of 20 strategies to improve the uptake of the 4Ms, MinuteClinic achieved the IHI Committed to Care Excellence recognition. A significant increase over time in the reliable delivery of all 4Ms and each M component individually was found. For the research, there were significant improvements in the mean number of Ms delivered per visit (M-Score) in the Virtual Clinic (Incident Rate Ratio [IRR]: 2.47, p = 0.001) and PDSA (IRR: 3.08, p = 0.002) strategy intervention groups when compared to controls. CONCLUSIONS: Application of quality improvement and implementation methodologies contributed to the success of implementing age-friendly 4Ms evidence-based practice.

Anti-CRISPR proteins function through thermodynamic tuning and allosteric regulation of CRISPR RNA-guided surveillance complex.

CRISPR RNA-guided detection and degradation of foreign DNA is a dynamic process. Viruses can interfere with this cellular defense by expressing small proteins called anti-CRISPRs. While structural models of anti-CRISPRs bound to their target complex provide static snapshots that inform mechanism, the dynamics and thermodynamics of these interactions are often overlooked. Here, we use hydrogen deuterium exchange-mass spectrometry (HDX-MS) and differential scanning fluorimetry (DSF) experiments to determine how anti-CRISPR binding impacts the conformational landscape of the type IF CRISPR RNA guided surveillance complex (Csy) upon binding of two different anti-CRISPR proteins (AcrIF9 and AcrIF2). The results demonstrate that AcrIF2 binding relies on enthalpic stabilization, whereas AcrIF9 uses an entropy driven reaction to bind the CRISPR RNA-guided surveillance complex. Collectively, this work reveals the thermodynamic basis and mechanistic versatility of anti-CRISPR-mediated immune suppression. More broadly, this work presents a striking example of how allosteric effectors are employed to regulate nucleoprotein complexes.

Rtt105 regulates RPA function by configurationally stapling the flexible domains.

Replication Protein A (RPA) is a heterotrimeric complex that binds to single-stranded DNA (ssDNA) and recruits over three dozen RPA-interacting proteins to coordinate multiple aspects of DNA metabolism including DNA replication, repair, and recombination. Rtt105 is a molecular chaperone that regulates nuclear localization of RPA. Here, we show that Rtt105 binds to multiple DNA binding and protein-interaction domains of RPA and configurationally staples the complex. In the absence of ssDNA, Rtt105 inhibits RPA binding to Rad52, thus preventing spurious binding to RPA-interacting proteins. When ssDNA is available, Rtt105 promotes formation of high-density RPA nucleoprotein filaments and dissociates during this process. Free Rtt105 further stabilizes the RPA-ssDNA filaments by inhibiting the facilitated exchange activity of RPA. Collectively, our data suggest that Rtt105 sequesters free RPA in the nucleus to prevent untimely binding to RPA-interacting proteins, while stabilizing RPA-ssDNA filaments at DNA lesion sites.

Student Perceptions of an Interprofessional Short Course Designed to Increase Awareness of Human Trafficking.

Human trafficking is a global problem with significant impacts on victims' physical and emotional health. Many health care professionals lack human trafficking knowledge, leading to missed opportunities for intervention. This cross-sectional study used evaluation data from a short course on human trafficking to evaluate the course's perceived impact on students. Closed-ended questions were analyzed descriptively while open-ended questions were analyzed using qualitative content analysis. A total of 241 students across eight professions/disciplines completed the evaluation. The vast majority indicated course content was valuable, applicable to their future practice, and recognized interprofessional teamwork is needed to address human trafficking. Despite course effectiveness, there remains a need to continue expanding interprofessional engagement and examining the longitudinal impact of this educational effort.

Core Protein-Directed Antivirals and Importin ß Can Synergistically Disrupt Hepatitis B Virus Capsids.

Viral structural proteins can have multiple activities. Antivirals that target structural proteins have potential to exhibit multiple antiviral mechanisms. Hepatitis B virus (HBV) core protein (Cp) is involved in most stages of the viral life cycle; it assembles into capsids, packages viral RNA, is a metabolic compartment for reverse transcription, interacts with nuclear trafficking machinery, and disassembles to release the viral genome into the nucleus. During nuclear localization, HBV capsids bind to host importins (e.g., Impß) via Cp's C-terminal domain (CTD); the CTD is localized to the interior of the capsid and is transiently exposed on the exterior. We used HAP12 as a representative Cp allosteric modulator (CpAM), a class of antivirals that inappropriately stimulates and misdirects HBV assembly and deforms capsids. CpAM impact on other aspects of the HBV life cycle is poorly understood. We investigate how HAP12 influences the interactions between empty or RNA-filled capsids with Impß and trypsin in vitro. We show that HAP12 can modulate CTD accessibility and capsid stability, depending on the saturation of HAP12-binding sites. We demonstrate that Impß synergistically contributes to capsid disruption at high levels of HAP12 saturation, using electron microscopy to visualize the disruption and rearrangement of Cp dimers into aberrant complexes. However, RNA-filled capsids resist the destabilizing effects of HAP12 and Impß. In summary, we show host protein-induced catalysis of capsid disruption, an unexpected additional mechanism of action for CpAMs. Potentially, untimely capsid disassembly can hamper the HBV life cycle and also cause the virus to become vulnerable to host innate immune responses. IMPORTANCE The HBV core, an icosahedral complex of 120 copies of the homodimeric core (capsid) protein with or without packaged nucleic acid, is transported to the host nucleus by its interaction with host importin proteins. Importin-core interaction requires the core protein C-terminal domain, which is inside the capsid, to "flip" to the capsid exterior. Core protein-directed drugs that affect capsid assembly and stability have been developed recently. We show that these molecules can, synergistically with importins, disrupt capsids. This mechanism of action, synergism with host protein, has the potential to disrupt the virus life cycle and activate the innate immune system.

Facilitators and barriers to post-discharge pain assessment and triage: a qualitative study of nurses' and patients' perspectives.

BACKGROUND: After hospital discharge, patients can experience symptoms prompting them to seek acute medical attention. Early evaluation of patients' post-discharge symptoms by healthcare providers may improve appropriate healthcare utilization and patient safety. Post-discharge follow-up phone calls, which are used for routine transitional care in U.S. hospitals, serve as an important channel for provider-patient communication about symptoms. This study aimed to assess the facilitators and barriers to evaluating and triaging pain symptoms in cardiovascular patients through follow-up phone calls after their discharge from a large healthcare system in Central Massachusetts. We also discuss strategies that may help address the identified barriers. METHODS: Guided by the Practical, Robust, Implementation and Sustainability Model (PRISM), we completed semi-structured interviews with 7 nurses and 16 patients in 2020. Selected nurses conducted (or supervised) post-discharge follow-up calls on behalf of 5 clinical teams (2 primary care; 3 cardiology). We used thematic analysis to identify themes from interviews and mapped them to the domains of the PRISM model. RESULTS: Participants described common facilitators and barriers related to the four domains of PRISM: Intervention (I), Recipients (R), Implementation and Sustainability Infrastructure (ISI), and External Environment (EE). Facilitators include: (1) patients being willing to receive provider follow-up (R); (2) nurses experienced in symptom assessment (R); (3) good care coordination within individual clinical teams (R); (4) electronic health record system and call templates to support follow-up calls (ISI); and (5) national and institutional policies to support post-discharge follow-up (EE). Barriers include: (1) limitations of conducting symptom assessment by provider-initiated follow-up calls (I); (2) difficulty connecting patients and providers in a timely manner (R); (3) suboptimal coordination for transitional care among primary care and cardiology providers (R); and (4) lack of emphasis on post-discharge follow-up call reimbursement among cardiology clinics (EE). Specific barriers for pain assessment include: (1) concerns with pain medication misuse (R); and (2) no standardized pain assessment and triage protocol (ISI). CONCLUSIONS: Strategies to empower patients, facilitate timely patient-provider communication, and support care coordination regarding pain evaluation and treatment may reduce the barriers and improve processes and outcomes of pain assessment and triage.

Aerobic bacterial methane synthesis.

Reports of biogenic methane (CH4) synthesis associated with a range of organisms have steadily accumulated in the literature. This has not happened without controversy and in most cases the process is poorly understood at the gene and enzyme levels. In marine and freshwater environments, CH4 supersaturation of oxic surface waters has been termed the "methane paradox" because biological CH4 synthesis is viewed to be a strictly anaerobic process carried out by O2-sensitive methanogens. Interest in this phenomenon has surged within the past decade because of the importance of understanding sources and sinks of this potent greenhouse gas. In our work on Yellowstone Lake in Yellowstone National Park, we demonstrate microbiological conversion of methylamine to CH4 and isolate and characterize an Acidovorax sp. capable of this activity. Furthermore, we identify and clone a gene critical to this process (encodes pyridoxylamine phosphate-dependent aspartate aminotransferase) and demonstrate that this property can be transferred to Escherichia coli with this gene and will occur as a purified enzyme. This previously unrecognized process sheds light on environmental cycling of CH4, suggesting that O2-insensitive, ecologically relevant aerobic CH4 synthesis is likely of widespread distribution in the environment and should be considered in CH4 modeling efforts.

Health-Related Goal Setting and Achievement Among Veterans with High Technology Adoption.

BACKGROUND: There is increasing recognition of the importance of supporting patients in their health-related goals. Patient-provider discussions and health-related mobile applications (apps) can support patients to pursue health goals; however, their impact on patient goal setting and achievement is not well understood. OBJECTIVE: To examine the relationships between the following: (1) patient demographics, patient-provider discussions, and health-related goal setting and achievement, and (2) patient mobile health app use and goal achievement. DESIGN: Cross-sectional survey. PARTICIPANTS: Veterans who receive Veterans Health Administration (VA) healthcare and are users of VA patient-facing technology. MAIN MEASURES: Veteran demographics, goal-related behaviors, and goal achievement. METHODS: Veterans were invited to participate in a telephone survey. VA administrative data were linked to survey data for additional health and demographic information. Logistic regression models were run to identify factors that predict health-related goal setting and achievement. KEY RESULTS: Among respondents (n=2552), 75% of patients indicated having set health goals in the preceding 6 months and approximately 42% reported achieving their goal. Men (vs. women) had lower odds of setting goals (OR: 0.71; CI95: 0.53-0.97), as did individuals with worse (vs. better) health (OR: 0.18; CI95: 0.04-0.88). Individuals with advanced education-some college/college degrees, and post-college degrees (vs. no college education)-demonstrated higher odds of setting goals (OR: 1.35; CI95: 1.01-1.79; OR: 1.71; CI95: 1.28-2.28, respectively). Those who reported having discussed their goals with their providers were more likely to set goals (OR: 3.60; CI95: 2.97-4.35). Patient mobile health app use was not statistically associated with goal achievement. CONCLUSIONS: Efforts to further promote patient-led goal setting should leverage the influence of patient-provider conversations. Use of patient-facing technologies, specifically mobile health apps, may facilitate goal-oriented care, but further work is needed to examine the potential benefits of apps to support patient goals, particularly if providers discuss and endorse use of those apps with patients.

Hydrogen-deuterium exchange reveals a dynamic DNA-binding map of replication protein A.

Replication protein A (RPA) binds to single-stranded DNA (ssDNA) and interacts with over three dozen enzymes and serves as a recruitment hub to coordinate most DNA metabolic processes. RPA binds ssDNA utilizing multiple oligosaccharide/oligonucleotide binding domains and based on their individual DNA binding affinities are classified as high versus low-affinity DNA-binding domains (DBDs). However, recent evidence suggests that the DNA-binding dynamics of DBDs better define their roles. Utilizing hydrogen-deuterium exchange mass spectrometry (HDX-MS), we assessed the ssDNA-driven dynamics of the individual domains of human RPA. As expected, ssDNA binding shows HDX changes in DBDs A, B, C, D and E. However, DBD-A and DBD-B are dynamic and do not show robust DNA-dependent protection. DBD-C displays the most extensive changes in HDX, suggesting a major role in stabilizing RPA on ssDNA. Slower allosteric changes transpire in the protein-protein interaction domains and linker regions, and thus do not directly interact with ssDNA. Within a dynamics-based model for RPA, we propose that DBD-A and -B act as the dynamic half and DBD-C, -D and -E function as the less-dynamic half. Thus, segments of ssDNA buried under the dynamic half are likely more readily accessible to RPA-interacting proteins.

The flexible N-terminus of BchL autoinhibits activity through interaction with its [4Fe-4S] cluster and released upon ATP binding.

A key step in bacteriochlorophyll biosynthesis is the reduction of protochlorophyllide to chlorophyllide, catalyzed by dark-operative protochlorophyllide oxidoreductase. Dark-operative protochlorophyllide oxidoreductase contains two [4Fe-4S]-containing component proteins (BchL and BchNB) that assemble upon ATP binding to BchL to coordinate electron transfer and protochlorophyllide reduction. But the precise nature of the ATP-induced conformational changes is poorly understood. We present a crystal structure of BchL in the nucleotide-free form where a conserved, flexible region in the N-terminus masks the [4Fe-4S] cluster at the docking interface between BchL and BchNB. Amino acid substitutions in this region produce a hyperactive enzyme complex, suggesting a role for the N-terminus in autoinhibition. Hydrogen-deuterium exchange mass spectrometry shows that ATP binding to BchL produces specific conformational changes leading to release of the flexible N-terminus from the docking interface. The release also promotes changes within the local environment surrounding the [4Fe-4S] cluster and promotes BchL-complex formation with BchNB. A key patch of amino acids, Asp-Phe-Asp (the 'DFD patch'), situated at the mouth of the BchL ATP-binding pocket promotes intersubunit cross stabilization of the two subunits. A linked BchL dimer with one defective ATP-binding site does not support protochlorophyllide reduction, illustrating nucleotide binding to both subunits as a prerequisite for the intersubunit cross stabilization. The masking of the [4Fe-4S] cluster by the flexible N-terminal region and the associated inhibition of the activity is a novel mechanism of regulation in metalloproteins. Such mechanisms are possibly an adaptation to the anaerobic nature of eubacterial cells with poor tolerance for oxygen.

Supporting the Implementation of Connected Care Technologies in the Veterans Health Administration: Cross-Sectional Survey Findings from the Veterans Engagement with Technology Collaborative (VET-C) Cohort.

BACKGROUND: Widespread adoption, use, and integration of patient-facing technologies into the workflow of health care systems has been slow, thus limiting the realization of their potential. A growing body of work has focused on how best to promote adoption and use of these technologies and measure their impacts on processes of care and outcomes. This body of work currently suffers from limitations (eg, cross-sectional analyses, limited patient-generated data linked with clinical records) and would benefit from institutional infrastructure to enhance available data and integrate the voice of the patient into implementation and evaluation efforts. OBJECTIVE: The Veterans Health Administration (VHA) has launched an initiative called the Veterans Engagement with Technology Collaborative cohort to directly address these challenges. This paper reports the process by which the cohort was developed and describes the baseline data being collected from cohort members. The overarching goal of the Veterans Engagement with Technology Collaborative cohort is to directly engage veterans in the evaluation of new VHA patient-facing technologies and in so doing, to create new infrastructure to support related quality improvement and evaluation activities. METHODS: Inclusion criteria for veterans to be eligible for membership in the cohort included being an active user of VHA health care services, having a mobile phone, and being an established user of existing VHA patient-facing technologies as represented by use of the secure messaging feature of VHA's patient portal. Between 2017 and 2018, we recruited veterans who met these criteria and administered a survey to them over the telephone. RESULTS: The majority of participants (N=2727) were male (2268/2727, 83.2%), White (2226/2727, 81.6%), living in their own apartment or house (2519/2696, 93.4%), and had completed some college (1176/2701, 43.5%) or an advanced degree (1178/2701, 43.6%). Cohort members were 59.9 years old, on average. The majority self-reported their health status as being good (1055/2725, 38.7%) or very good (524/2725, 19.2%). Most cohort members owned a personal computer (2609/2725, 95.7%), tablet computer (1616/2716, 59.5%), and/or smartphone (2438/2722, 89.6%). CONCLUSIONS: The Veterans Engagement with Technology Collaborative cohort is an example of a VHA learning health care system initiative designed to support the data-driven implementation of patient-facing technologies into practice and measurement of their impacts. With this initiative, VHA is building capacity for future, rapid, rigorous evaluation and quality improvement efforts to enhance understanding of the adoption, use, and impact of patient-facing technologies.

Dynamics of Hepatitis B Virus Capsid Protein Dimer Regulate Assembly through an Allosteric Network.

While there is an effective vaccine for Human Hepatitis B Virus (HBV), 257 million people have chronic infections for which there is no cure. The assembly process for the viral capsid is a potential therapeutic target. In order to understand the capsid assembly process, we investigated the dimeric building blocks of the capsid. To understand what blocks assembly, we took advantage of an assembly incompetent mutant dimer, Cp149-Y132A, located in the interdimer interface. This mutation leads to changes in protein dynamics throughout the structure of the dimer as measured by hydrogen-deuterium exchange mass spectrometry (HDX-MS). To further understand how the HBV capsid assembles, the homologue woodchuck HBV (WHV) capsid protein dimer (Cp) was used. WHV is more stable than HBV in HDX-MS and native mass spectrometry experiments. Because the WHV Cp assembles more rapidly into viral capsids than HBV, it was suspected that an increase in stability of the intradimer interface and/or in the contact region leads to increased assembly rates. The differences in dynamics when comparing HBV and human Cp149-Y132A as well as the differences in dynamics when comparing the HBV and WHV Cps allowed us to map an allosteric network within the HBV dimer. Through a careful comparison of structure, stability, and dynamics using four different capsid protein dimers, we conclude that protein subunit dynamics regulate HBV capsid assembly.

Meeting Global Rehabilitation Needs: The Development and Evaluation of an International Visiting Rehabilitation Student Program.

Collaboration to increase capacity for healthcare professionals requires careful planning, open communication, implementation, formative and summative evaluation, and sustainability. International collaboration to meet the rehabilitation needs of China requires a supportive structure of faculty and staff implementing the program. The purpose of this article is to explore the development of a collaborative international rehabilitation education program and illustrate outcomes as they relate to professional development, cultural competency, and healthcare team skills. A retrospective analysis of program assessment data was completed including pre and posttest survey results and focused interviews. Results indicate that program participants had a significant positive change in values and beliefs towards cultural diversity and increased awareness of interdisciplinary team skills which contributed to overall professional development as future rehabilitation practitioners. The description and assessment of the program also serves as a framework for the development of future collaborative international rehabilitation education programs. Future research could explore institutional growth and faculty development of collaborating educational institutions.

Biophysical characterization of SARAH domain-mediated multimerization of Hippo pathway complexes in Drosophila.

Hippo pathway signaling limits cell growth and proliferation and maintains the stem-cell niche. These cellular events result from the coordinated activity of a core kinase cassette that is regulated, in part, by interactions involving Hippo, Salvador, and dRassF. These interactions are mediated by a conserved coiled-coil domain, termed SARAH, in each of these proteins. SARAH domain-mediated homodimerization of Hippo kinase leads to autophosphorylation and activation. Paradoxically, SARAH domain-mediated heterodimerization between Hippo and Salvador enhances Hippo kinase activity in cells, whereas complex formation with dRassF inhibits it. To better understand the mechanism by which each complex distinctly modulates Hippo kinase and pathway activity, here we biophysically characterized the entire suite of SARAH domain-mediated complexes. We purified the three SARAH domains from Drosophila melanogaster and performed an unbiased pulldown assay to identify all possible interactions, revealing that isolated SARAH domains are sufficient to recapitulate the cellular assemblies and that Hippo is a universal binding partner. Additionally, we found that the Salvador SARAH domain homodimerizes and demonstrate that this interaction is conserved in Salvador's mammalian homolog. Using native MS, we show that each of these complexes is dimeric in solution. We also measured the stability of each SARAH domain complex, finding that despite similarities at both the sequence and structural levels, SARAH domain complexes differ in stability. The identity, stoichiometry, and stability of these interactions characterized here comprehensively reveal the nature of SARAH domain-mediated complex formation and provide mechanistic insights into how SARAH domain-mediated interactions influence Hippo pathway activity.

Intestinal Microbiome-Macrophage Crosstalk Contributes to Cholestatic Liver Disease by Promoting Intestinal Permeability in Mice.

BACKGROUND AND AIMS: Mounting evidence supports an association between cholestatic liver disease and changes in the composition of the microbiome. Still, the role of the microbiome in the pathogenesis of this condition remains largely undefined. APPROACH AND RESULTS: To address this, we have used two experimental models, administering alpha-naphtylisocyanate or feeding a 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet, to induce cholestatic liver disease in germ-free mice and germ-free mice conventionalized with the microbiome from wild-type, specific pathogen-free animals. Next, we have inhibited macrophage activation by depleting these cells using clodronate liposomes and inhibiting the inflammasome with a specific inhibitor of NOD-, LRR-, and pyrin domain-containing protein 3. Our results demonstrate that cholestasis, the accumulation of bile acids in the liver, fails to promote liver injury in the absence of the microbiome in vivo. Additional in vitro studies supported that endotoxin sensitizes hepatocytes to bile-acid-induced cell death. We also demonstrate that during cholestasis, macrophages contribute to promoting intestinal permeability and to altered microbiome composition through activation of the inflammasome, overall leading to increased endotoxin flux into the cholestatic liver. CONCLUSIONS: We demonstrate that the intestinal microbiome contributes to cholestasis-mediated cell death and inflammation through mechanisms involving activation of the inflammasome in macrophages.