The sustainability of exercise following colorectal surgery: A qualitative study of participants in the PREPARE-ABC trial

OBJECTIVE

This study aimed to explore perceptions regarding the sustainability of exercise following participation in a pre- and post-colorectal surgery exercise intervention trial (PREPARE-ABC).

DESIGN

Qualitative interview study. Data were analysed using framework analysis and independently coded by two researchers.

SETTING

Six United Kingdom National Health Service Trusts.

PARTICIPANTS

Eighteen interviews (hospital-based exercise n = 9, home-based exercise n = 3, standard care n = 6) were conducted with patients 12-15 months after being randomised in the trial, after their 12 month appointment.

INTERVENTION

Individuals who participated in one of two exercise intervention groups (hospital-supervised or home-supported exercise) or a standard care control group of the PREPARE-ABC trial were invited to interview.

RESULTS

The exercise interventions were reported to influence participants' recovery and future sustainability of exercise behaviour change. Several participants continued to engage in exercise over a year after their surgery. Reasons for this included being engaged with exercise prior to diagnosis, psychological benefits of exercise and wanting to be engaged with something to help recovery. Perceptions about the sustainability of active lifestyles were influenced by confidence to engage in structured exercise or physical activity and beliefs about its potential to promote future wellness.

CONCLUSIONS

Sustainability varies among individuals and early assessment of physical activity engagement could be beneficial. Physical activity interventions immediately following surgery may be important for future engagement.

Real-world evidence of sotrovimab effectiveness for preventing severe outcomes in patients with COVID-19: A quality improvement propensity-matched retrospective cohort study of a pan-provincial program in Alberta, Canada

OBJECTIVES

Post-marketing surveillance of sotrovimab's effect during implementation in the Canadian population is limited.

METHODS

The study used a propensity score-matched retrospective cohort design. Follow-up began between the periods of December 15, 2021 and April 30 2022. The study assessed any severe outcome defined as all-cause hospital admission or mortality within 30 days of a confirmed COVID-19-positive test. Covariate-adjusted odds ratios between sotrovimab treatment and the severe outcome was conducted using logistic regression.

RESULTS

There were 22,289 individuals meeting the treatment criteria for sotrovimab. There were 1603 treated and 6299 untreated individuals included in the analysis. The outcome occurrence in the study was 5.49% (treated) and 4.21% (untreated), with a median time from diagnosis to treatment of 1.00 days (interquartile range 2.00 days). In the propensity-matched cohort, sotrovimab was not associated with lower odds of a severe outcome (odds ratio 1.20, 95% confidence interval 0.91-1.58), adjusting for confounding variables.

CONCLUSIONS

After adjusting for confounding variables, sotrovimab treatment was not associated with lower odds of a severe outcome within 30-days of COVID-19-positive date.

Peroxisomal cholesterol metabolism regulates yap-signaling, which maintains intestinal epithelial barrier function and is altered in Crohn's disease

Intestinal epithelial cells line the luminal surface to establish the intestinal barrier, where the cells play essential roles in the digestion of food, absorption of nutrients and water, protection from microbial infections, and maintaining symbiotic interactions with the commensal microbial populations. Maintaining and coordinating all these functions requires tight regulatory signaling, which is essential for intestinal homeostasis and organismal health. Dysfunction of intestinal epithelial cells, indeed, is linked to gastrointestinal disorders such as irritable bowel syndrome, inflammatory bowel disease, and gluten-related enteropathies. Emerging evidence suggests that peroxisome metabolic functions are crucial in maintaining intestinal epithelial cell functions and intestinal epithelium regeneration and, therefore, homeostasis. Here, we investigated the molecular mechanisms by which peroxisome metabolism impacts enteric health using the fruit fly Drosophila melanogaster and murine model organisms and clinical samples. We show that peroxisomes control cellular cholesterol, which in turn regulates the conserved yes-associated protein-signaling and contributes to intestinal epithelial structure and epithelial barrier function. Moreover, analysis of intestinal organoid cultures derived from biopsies of patients affected by Crohn's Disease revealed that the dysregulation of peroxisome number, excessive cellular cholesterol, and inhibition of Yap-signaling are markers of disease and could be novel diagnostic and/or therapeutic targets for treating Crohn's Disease. Our studies provided mechanistic insights on peroxisomal signaling in intestinal epithelial cell functions and identified cholesterol as a novel metabolic regulator of yes-associated protein-signaling in tissue homeostasis.

Hsp90 inhibition leads to an increase in surface expression of multiple immunological receptors in cancer cells

Heat shock protein 90 (Hsp90) is a molecular chaperone important for maintaining protein homeostasis (proteostasis) in the cell. Hsp90 inhibitors are being explored as cancer therapeutics because of their ability to disrupt proteostasis. Inhibiting Hsp90 increases surface density of the immunological receptor Major Histocompatibility Complex 1 (MHC1). Here we show that this increase occurs across multiple cancer cell lines and with both cytosol-specific and pan-Hsp90 inhibitors. We demonstrate that Hsp90 inhibition also alters surface expression of both IFNGR and PD-L1, two additional immunological receptors that play a significant role in anti-tumour or anti-immune activity in the tumour microenvironment. Hsp90 also negatively regulates IFN-γ activity in cancer cells, suggesting it has a unique role in mediating the immune system's response to cancer. Our data suggests a strong link between Hsp90 activity and the pathways that govern anti-tumour immunity. This highlights the potential for the use of an Hsp90 inhibitor in combination with another currently available cancer treatment, immune checkpoint blockade therapy, which works to prevent immune evasion of cancer cells. Combination checkpoint inhibitor therapy and the use of an Hsp90 inhibitor may potentiate the therapeutic benefits of both treatments and improve prognosis for cancer patients.

Identifying and Addressing Nutritional Inequities and Psychosocial Needs of Cancer Patients Residing in Zip-Code Designated Food Priority Areas (FPAs)

PURPOSE/OBJECTIVE(S)

Nutrition is an essential aspect of cancer care at all time points leading to and after definitive therapy. Yet, cancer patients who reside in FPAs may experience limited access to healthy meals, possibly affecting cancer outcomes. There is no prospective data evaluating the consequence of residing in FPAs as it relates to perceived nutritional access, psychosocial needs, or nutritional status of cancer patients before, during, and after definitive treatment. Therefore, this study aims to characterize the nutritional needs of cancer patients undergoing curative radiation treatment (RT). We hypothesize that FPA residence will correlate with perceived lack of access to healthy food as well as other unmet psychosocial cancer needs at multiple time points during care.

MATERIALS/METHODS

Under IRB approval, a prospective, cross-sectional analysis was done using a questionnaire consolidated from previously validated surveys assessing the nutritional and psychosocial needs of patients with curable lung, head/neck, gynecological, or gastrointestinal cancers at different time points of cancer care (pre-treatment, 1 month, 6 months, and 1 year after completion of RT). Groups were compared using Χ2 and Mann-Whitney U tests as appropriate. Binary logistic regression was used to identify predictors of healthy food access.

RESULTS

From May 2019 to December 2022, 320 of 434 patients completed the survey, giving a compliance rate of 74%. Twenty-six percent of patients resided in zip-code designated FPAs. Patients who lived in FPAs were more likely to self-identify as black (60.5% vs 39.5%; p<0.001), single (p<0.001), have a lower median income (p<0.001), and were more likely to receive care at our inner-city photon therapy center (p<0.001) compared to non-FPA residents. Compared with non-FPA patients, the cohort who lived in FPAs had higher unmet nutritional needs (p = 0.003), which included a greater demand for healthier ways to eat (67.6%vs.54.4; p = 0.047) and a greater concern of having inadequate funds to buy healthy meals (44.4%vs.19.9%; p = 0.002). On MVA, marital status, median income, race, educational level and FPA residence were included, however only black race (OR:8.85; 95% CI:3.73-16.32; p<0.001) and education level (Elementary School: OR:8.32; 95% CI:1.19-58.33; p = 0.001, REF: Graduate/Professional) were predictors for nutritious meals uncertainty.

CONCLUSION

Inequities in nutritional needs were clearly identified in patients residing in FPAs when compared to non-FPA patients. Race and educational level are important factors in identifying patients in need of nutritional support. These demographics along with FPA-designated zip codes can be used to identify at-risk patients during clinic visits, where continuous nutritional and psychosocial support can be provided.

A Precision Medicine Navigator Can Mitigate Inequities Associated with Utilization of Genomic Tests in Black Men with Prostate Cancer

PURPOSE/OBJECTIVE(S)

Black men with prostate cancer in the United States experience disproportionately worse clinical outcomes compared to other racial groups. Identifying more reliable prognosticators to address these inequities has thus been the subject of considerable research scrutiny. However, prognostic genomic tools and genomic biorepositories suffer from an even greater lack of racial diversity. Strategies to mitigate these amplifying developments in inequities are desperately needed. We hypothesized that the presence of a precision medicine navigator (PMN) may mitigate inequities with standard of care (SOC) genomic test utilization among Black men with prostate cancer.

MATERIALS/METHODS

We retrospectively reviewed prostate cancer consults within one healthcare system from 11/2/2021 to 1/2/2022. We compared the frequency of patients who received SOC Decipher or Tempus genomic testing in the 7 months prior to the PMN start (pre-PMN) to the 7 months afterward (post-PMN). Chi square analysis was used to compare subgroups. Binary logistic regression was used to calculate the odds of receiving genomic testing.

RESULTS

The sample included 693 patients, 44.9% (311/693) pre-PMN and 55.1% (382/693) post-PMN, with a median age of 68 in both groups. Pre- and post-PMN racial distributions were similar with 60.1% and 60.2% White, 35.1% and 34% Black, 3.2% and 3.7% Asian/Pacific Islander, and 1.3% and 2.1% Latino, respectively. Pre- and post-PMN NCCN risk category distribution was 15.2% and 10.4% low risk, 46.8% and 49.9% intermediate risk, and 38.1% and 39.7% high risk, respectively. Pre- and post-PMN groups had 14.5% and 17% distant metastases, 77.2% and 76.9% localized disease, 10.3% and 10% prior prostatectomy, 47% and 51% income below sample median, 51% and 52% with Medicare/Medicaid, and 47% and 48% seen at community hospitals, respectively. There were no statistically significant differences for these variables pre- and post-PMN. However, from pre- to post-PMN, the proportion of Black patients receiving genomic testing increased from 19% to 58%. Black patients seen post-PMN were six times more likely to receive testing (p<0.001). Significant increases in SOC genomic testing post-PMN also occurred among lower median income patients, patients with Medicare/Medicaid, and community hospital patients.

CONCLUSION

The presence of a PMN may improve disparate rates of Black patients receiving SOC genomic tests for prostate cancer compared to other racial groups and may alleviate genomic testing inequities among other demographics.

Colorectal Cancer Immunotherapy: State of the Art and Future Directions

Cancer immunotherapy has become an indispensable mode of treatment for a multitude of solid tumor cancers. Colorectal cancer (CRC) has been one of the many cancer types to benefit from immunotherapy, especially in advanced disease where standard treatment fails to prevent recurrence or results in poor survival. The efficacy of immunotherapy in CRC has not been without challenge, as early clinical trials observed dismal responses in unselected CRC patients treated with checkpoint inhibitors. Many studies and clinical trials have since refined immunotherapies available for CRC, solidifying immunotherapy as a powerful asset for CRC treatment. This review article examines CRC immunotherapies, from their foundation, through emerging avenues for improvement, to future directions.

Activin A-Expressing Polymorphonuclear Myeloid-Derived Suppressor Cells Infiltrate Skeletal and Cardiac Muscle and Promote Cancer Cachexia

Cachexia is a major cause of death in cancer and leads to wasting of cardiac and skeletal muscle, as well as adipose tissue. Various cellular and soluble mediators have been postulated in driving cachexia; however, the specific mechanisms behind this muscle wasting remain poorly understood. In this study, we found polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) to be critical for the development of cancer-associated cachexia. Significant expansion of PMN-MDSCs was observed in the cardiac and skeletal muscles of cachectic murine models. Importantly, the depletion of this cell subset, using depleting anti-Ly6G Abs, attenuated this cachectic phenotype. To elucidate the mechanistic involvement of PMN-MDSCs in cachexia, we examined major mediators, that is, IL-6, TNF-α, and arginase 1. By employing a PMN-MDSC-specific Cre-recombinase mouse model, we showed that PMN-MDSCs were not maintained by IL-6 signaling. In addition, PMN-MDSC-mediated cardiac and skeletal muscle loss was not abrogated by deficiency in TNF-α or arginase 1. Alternatively, we found PMN-MDSCs to be critical producers of activin A in cachexia, which was noticeably elevated in cachectic murine serum. Moreover, inhibition of the activin A signaling pathway completely protected against cardiac and skeletal muscle loss. Collectively, we demonstrate that PMN-MDSCs are active producers of activin A, which in turn induces cachectic muscle loss. Targeting this immune/hormonal axis will allow the development of novel therapeutic interventions for patients afflicted with this debilitating syndrome.

Short chain fatty acids prime colorectal cancer cells to activate antitumor immunity

Introduction

Colorectal cancer (CRC) is a leading cause of death worldwide and its growth can either be promoted or inhibited by the metabolic activities of intestinal microbiota. Short chain fatty acids (SCFAs) are microbial metabolites with potent immunoregulatory properties yet there is a poor understanding of how they directly regulate immune modulating pathways within the CRC cells.

Methods

We used engineered CRC cell lines, primary organoid cultures, orthotopic in vivo models, and patient CRC samples to investigate how SCFA treatment of CRC cells regulates their ability to activate CD8+ T cells.

Results

CRC cells treated with SCFAs induced much greater activation of CD8+ T cells than untreated CRC cells. CRCs exhibiting microsatellite instability (MSI) due to inactivation of DNA mismatch repair were much more sensitive to SCFAs and induced much greater CD8+ T cell activation than chromosomally instable (CIN) CRCs with intact DNA repair, indicating a subtype-dependent response to SCFAs. This was due to SCFA-induced DNA damage that triggered upregulation of chemokine, MHCI, and antigen processing or presenting genes. This response was further potentiated by a positive feedback loop between the stimulated CRC cells and activated CD8+ T cells in the tumor microenvironment. The initiating mechanism in the CRCs was inhibition of histone deacetylation by the SCFAs that triggered genetic instability and led to an overall upregulation of genes associated with SCFA signaling and chromatin regulation. Similar gene expression patterns were found in human MSI CRC samples and in orthotopically grown MSI CRCs independent of the amount of SCFA producing bacteria in the intestine.

Discussion

MSI CRCs are widely known to be more immunogenic than CIN CRCs and have a much better prognosis. Our findings indicate that a greater sensitivity to microbially produced SCFAs contributes to the successful activation of CD8+ T cells by MSI CRCs, thereby identifying a mechanism that could be therapeutically targeted to improve antitumor immunity in CIN CRCs.

Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors

BACKGROUND

Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse FXa inhibitors. ANNEXA-4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) was a multicenter, prospective, phase-3b/4, single-group cohort study that evaluated andexanet alfa in patients with acute major bleeding. The results of the final analyses are presented.

METHODS

Patients with acute major bleeding within 18 hours of FXa inhibitor administration were enrolled. Co-primary end points were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy, defined by a scale used in previous reversal studies, at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds (≥75 ng/mL for apixaban and rivaroxaban, ≥40 ng/mL for edoxaban, and ≥0.25 IU/mL for enoxaparin; reported in the same units used for calibrators) who were adjudicated as meeting major bleeding criteria (modified International Society of Thrombosis and Haemostasis definition). The safety population included all patients. Major bleeding criteria, hemostatic efficacy, thrombotic events (stratified by occurring before or after restart of either prophylactic [ie, a lower dose, for prevention rather than treatment] or full-dose oral anticoagulation), and deaths were assessed by an independent adjudication committee. Median endogenous thrombin potential at baseline and across the follow-up period was a secondary outcome.

RESULTS

There were 479 patients enrolled (mean age, 78 years; 54% male, 86% White; 81% anticoagulated for atrial fibrillation at a median time of 11.4 hours since last dose, with 245 (51%) on apixaban, 176 (37%) on rivaroxaban, 36 (8%) on edoxaban, and 22 (5%) on enoxaparin. Bleeding was predominantly intracranial (n=331 [69%]) or gastrointestinal (n=109 [23%]). In evaluable apixaban patients (n=172), median anti-FXa activity decreased from 146.9 ng/mL to 10.0 ng/mL (reduction, 93% [95% CI, 94-93]); in rivaroxaban patients (n=132), it decreased from 214.6 ng/mL to 10.8 ng/mL (94% [95% CI, 95-93]); in edoxaban patients (n=28), it decreased from 121.1 ng/mL to 24.4 ng/mL (71% [95% CI, 82-65); and in enoxaparin patients (n=17), it decreased from 0.48 IU/mL to 0.11 IU/mL (75% [95% CI, 79-67]). Excellent or good hemostasis occurred in 274 of 342 evaluable patients (80% [95% CI, 75-84]). In the safety population, thrombotic events occurred in 50 patients (10%); in 16 patients, this occurred during treatment with prophylactic anticoagulation that began after the bleeding event. No thrombotic episodes occurred after oral anticoagulation restart. Specific to certain populations, reduction of anti-FXa activity from baseline to nadir significantly predicted hemostatic efficacy in patients with intracranial hemorrhage (area under the receiver operating characteristic curve, 0.62 [95% CI, 0.54-0.70]) and correlated with lower mortality in patients <75 years of age (adjusted P=0.022; unadjusted P=0.003). Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors.

CONCLUSIONS

In patients with major bleeding associated with the use of FXa inhibitors, treatment with andexanet alfa reduced anti-FXa activity and was associated with good or excellent hemostatic efficacy in 80% of patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02329327.

Investigation of the gut microbiome, bile acid composition and host immunoinflammatory response in a model of azoxymethane-induced colon cancer at discrete timepoints

BACKGROUND

Distinct sets of microbes contribute to colorectal cancer (CRC) initiation and progression. Some occur due to the evolving intestinal environment but may not contribute to disease. In contrast, others may play an important role at particular times during the tumorigenic process. Here, we describe changes in the microbiota and host over the course of azoxymethane (AOM)-induced tumorigenesis.

METHODS

Mice were administered AOM or PBS and were euthanised 8, 12, 24 and 48 weeks later. Samples were analysed using 16S rRNA gene sequencing, UPLC-MS and qRT-PCR.

RESULTS

The microbiota and bile acid profile showed distinct changes at each timepoint. The inflammatory response became apparent at weeks 12 and 24. Moreover, significant correlations between individual taxa, cytokines and bile acids were detected. One co-abundance group (CAG) differed significantly between PBS- and AOM-treated mice at week 24. Correlation analysis also revealed significant associations between CAGs, bile acids and the bile acid transporter, ASBT. Aberrant crypt foci and adenomas were first detectable at weeks 24 and 48, respectively.

CONCLUSION

The observed changes precede host hyperplastic transformation and may represent early therapeutic targets for the prevention or management of CRC at specific timepoints in the tumorigenic process.

Understanding and addressing vaccine hesitancy in the context of COVID-19: development of a digital intervention

OBJECTIVES

Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) was identified in late 2019, spreading to over 200 countries and resulting in almost two million deaths worldwide. The emergence of safe and effective vaccines provides a route out of the pandemic, with vaccination uptake of 75-90% needed to achieve population protection. Vaccine hesitancy is problematic for vaccine rollout; global reports suggest only 73% of the population may agree to being vaccinated. As a result, there is an urgent need to develop equitable and accessible interventions to address vaccine hesitancy at the population level.

STUDY DESIGN

& Method: We report the development of a scalable digital intervention seeking to address COVID-19 vaccine hesitancy and enhance uptake of COVID-19 vaccines in the United Kingdom. Guided by motivational interviewing (MI) principles, the intervention includes a series of therapeutic dialogues addressing 10 key concerns of vaccine-hesitant individuals. Development of the intervention occurred linearly across four stages. During stage 1, we identified common reasons for COVID-19 vaccine hesitancy through analysis of existing survey data, a rapid systematic literature review, and public engagement workshops. Stage 2 comprised qualitative interviews with medical, immunological, and public health experts. Rapid content and thematic analysis of the data provided evidence-based responses to common vaccine concerns. Stage 3 involved the development of therapeutic dialogues through workshops with psychological and digital behaviour change experts. Dialogues were developed to address concerns using MI principles, including embracing resistance and supporting self-efficacy. Finally, stage 4 involved digitisation of the dialogues and pilot testing with members of the public.

DISCUSSION

The digital intervention provides an evidence-based approach to addressing vaccine hesitancy through MI principles. The dialogues are user-selected, allowing exploration of relevant issues associated with hesitancy in a non-judgmental context. The text-based content and digital format allow for rapid modification to changing information and scalability for wider dissemination.

837 High Prevalence of Anaemia and Mortality in Older Patients Undergoing Emergency Laparotomy

Aim

Anaemia affects 1in10 elderly (&gt;65) patients with a myriad of causes. Elderly patients undergoing emergency laparotomy often present with anaemia. Little is known however about the prevalence of anaemia in older people who require emergency laparotomy and the influence it may have on their outcomes.

Method

Elderly patients (&gt;65-years old) undergoing an emergency laparotomy between May2016-November2018 in a tertiary trauma centre were prospectively identified. Data included patient demographics, haemoglobin, MCV and ferritin, blood transfusions and iron products administered, readmissions and mortality.

Results

231 patients underwent emergency laparotomy. Prevalence of pre-operative anaemia in this group was 43%. 5% were very-anaemic and 38% mildly-anaemic. Ferritin was checked within 89 patients; insufficient levels were present in 20%. 31% of all patients were given blood in the peri-operative period. 100% of patients discharged, were anaemic. For pre-operative anaemic vs non-anaemic patients, ASA grade was higher (4 vs 3), readmission rate was 19% vs 18%, 30-day mortality was 18% vs 14% and 1-year mortality rate high(34% vs 22%, p &lt; 0.05). Very-anaemic patients (92%) received peri-operative blood compared to (41%) of mildly-anaemic patients. 30-day mortality was 0 vs 21% in very-anaemic vs mildly-anaemic patients. Mortality was 45.8% in patients who received transfusions compared to those who did not 19.9% (P &lt; 0.0001).

Conclusions

The prevalence of anaemia in older patients undergoing emergency laparotomy is high and related to significantly increased mortality(12 months after surgery). We have identified a high-risk group of older patients with mild anaemia on presentation who may be at increased risk of mortality 3months after surgery.

Anti-tumor immunity in mismatch repair-deficient colorectal cancers requires type I IFN-driven CCL5 and CXCL10

Colorectal cancers (CRCs) deficient in DNA mismatch repair (dMMR) contain abundant CD8+ tumor-infiltrating lymphocytes (TILs) responding to the abundant neoantigens from their unstable genomes. Priming of such tumor-targeted TILs first requires recruitment of CD8+ T cells into the tumors, implying that this is an essential prerequisite of successful dMMR anti-tumor immunity. We have discovered that selective recruitment and activation of systemic CD8+ T cells into dMMR CRCs strictly depend on overexpression of CCL5 and CXCL10 due to endogenous activation of cGAS/STING and type I IFN signaling by damaged DNA. TIL infiltration into orthotopic dMMR CRCs is neoantigen-independent and followed by induction of a resident memory-like phenotype key to the anti-tumor response. CCL5 and CXCL10 could be up-regulated by common chemotherapies in all CRCs, indicating that facilitating CD8+ T cell recruitment underlies their efficacy. Induction of CCL5 and CXCL10 thus represents a tractable therapeutic strategy to induce TIL recruitment into CRCs, where local priming can be maximized even in neoantigen-poor CRCs.

FcRn is a CD32a coreceptor that determines susceptibility to IgG immune complex-driven autoimmunity

IgG immune complexes (ICs) promote autoimmunity through binding fragment crystallizable (Fc) γ-receptors (FcγRs). Of these, the highly prevalent FcγRIIa (CD32a) histidine (H)-131 variant (CD32a^H) is strongly linked to human autoimmune diseases through unclear mechanisms. We show that, relative to the CD32a arginine (R)-131 (CD32a^R) variant, CD32a^H more avidly bound human (h) IgG1 IC and formed a ternary complex with the neonatal Fc receptor (FcRn) under acidic conditions. In primary human and mouse cells, both CD32a variants required FcRn to induce innate and adaptive immune responses to hIgG1 ICs, which were augmented in the setting of CD32a^H. Conversely, FcRn induced responses to IgG IC independently of classical FcγR, but optimal responses required FcRn and FcγR. Finally, FcRn blockade decreased inflammation in a rheumatoid arthritis model without reducing circulating autoantibody levels, providing support for FcRn’s direct role in IgG IC-associated inflammation. Thus, CD32a and FcRn coregulate IgG IC-mediated immunity in a manner favoring the CD32a^H variant, providing a novel mechanism for its disease association.

Record Energetics for an Inertial Fusion Implosion at NIF

Inertial confinement fusion seeks to create burning plasma conditions in a spherical capsule implosion, which requires efficiently absorbing the driver energy in the capsule, transferring that energy into kinetic energy of the imploding DT fuel and then into internal energy of the fuel at stagnation. We report new implosions conducted on the National Ignition Facility (NIF) with several improvements on recent work [Phys. Rev. Lett. 120, 245003 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.245003; Phys. Rev. E 102, 023210 (2020)PRESCM2470-004510.1103/PhysRevE.102.023210]: larger capsules, thicker fuel layers to mitigate fuel-ablator mix, and new symmetry control via cross-beam energy transfer; at modest velocities, these experiments achieve record values for the implosion energetics figures of merit as well as fusion yield for a NIF experiment.

Evidence of Three-Dimensional Asymmetries Seeded by High-Density Carbon-Ablator Nonuniformity in Experiments at the National Ignition Facility

Inertial confinement fusion implosions must achieve high in-flight shell velocity, sufficient energy coupling between the hot spot and imploding shell, and high areal density (ρR=∫ρdr) at stagnation. Asymmetries in ρR degrade the coupling of shell kinetic energy to the hot spot and reduce the confinement of that energy. We present the first evidence that nonuniformity in the ablator shell thickness (∼0.5% of the total thickness) in high-density carbon experiments is a significant cause for observed 3D ρR asymmetries at the National Ignition Facility. These shell-thickness nonuniformities have significantly impacted some recent experiments leading to ρR asymmetries on the order of ∼25% of the average ρR and hot spot velocities of ∼100  km/s. This work reveals the origin of a significant implosion performance degradation in ignition experiments and places stringent new requirements on capsule thickness metrology and symmetry.

Foam-lined hohlraum, inertial confinement fusion experiments on the National Ignition Facility

Experiments on the National Ignition Facility (NIF) to study hohlraums lined with a 20-mg/cc 400-μm-thick Ta_{2}O_{5} aerogel at full scale (hohlraum diameter = 6.72 mm) are reported. Driven with a 1.6-MJ, 450-TW laser pulse, the performance of the foam liner is diagnosed using implosion hot-spot symmetry measurements of the high-density carbon (HDC) capsule and measurement of inner beam propagation through a thin-wall 8-μm Au window in the hohlraum. Results show an improved capsule performance due to laser energy deposition further inside the hohlraum, leading to a modest increase in x-ray drive and reduced preheat due to changes in the x-ray spectrum when the foam liner is included. In addition, the outer cone bubble uniformity is improved, but the predicted improvement in inner beam propagation to improve symmetry control is not realized for this foam thickness and density.

The skin microbiome of elasmobranchs follows phylosymbiosis, but in teleost fishes, the microbiomes converge

BACKGROUND

The vertebrate clade diverged into Chondrichthyes (sharks, rays, and chimeras) and Osteichthyes fishes (bony fishes) approximately 420 mya, with each group accumulating vast anatomical and physiological differences, including skin properties. The skin of Chondrichthyes fishes is covered in dermal denticles, whereas Osteichthyes fishes are covered in scales and are mucous rich. The divergence time among these two fish groups is hypothesized to result in predictable variation among symbionts. Here, using shotgun metagenomics, we test if patterns of diversity in the skin surface microbiome across the two fish clades match predictions made by phylosymbiosis theory. We hypothesize (1) the skin microbiome will be host and clade-specific, (2) evolutionary difference in elasmobranch and teleost will correspond with a concomitant increase in host-microbiome dissimilarity, and (3) the skin structure of the two groups will affect the taxonomic and functional composition of the microbiomes.

RESULTS

We show that the taxonomic and functional composition of the microbiomes is host-specific. Teleost fish had lower average microbiome within clade similarity compared to among clade comparison, but their composition is not different among clade in a null based model. Elasmobranch's average similarity within clade was not different than across clade and not different in a null based model of comparison. In the comparison of host distance with microbiome distance, we found that the taxonomic composition of the microbiome was related to host distance for the elasmobranchs, but not the teleost fishes. In comparison, the gene function composition was not related to the host-organism distance for elasmobranchs but was negatively correlated with host distance for teleost fishes.

CONCLUSION

Our results show the patterns of phylosymbiosis are not consistent across both fish clades, with the elasmobranchs showing phylosymbiosis, while the teleost fish are not. The discrepancy may be linked to alternative processes underpinning microbiome assemblage, including possible historical host-microbiome evolution of the elasmobranchs and convergent evolution in the teleost which filter specific microbial groups. Our comparison of the microbiomes among fishes represents an investigation into the microbial relationships of the oldest divergence of extant vertebrate hosts and reveals that microbial relationships are not consistent across evolutionary timescales. Video abstract.