Germinal center responses to SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals.

Vaccine-mediated immunity often relies on the generation of protective antibodies and memory B cells, which commonly stem from germinal center (GC) reactions. An in-depth comparison of the GC responses elicited by SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals has not yet been performed due to the challenge of directly probing human lymph nodes. Herein, through a fine-needle aspiration-based approach, we profiled the immune responses to SARS-CoV-2 mRNA vaccines in lymph nodes of healthy individuals and kidney transplant recipients (KTXs). We found that, unlike healthy subjects, KTXs presented deeply blunted SARS-CoV-2-specific GC B cell responses coupled with severely hindered T follicular helper cell, SARS-CoV-2 receptor binding domain-specific memory B cell, and neutralizing antibody responses. KTXs also displayed reduced SARS-CoV-2-specific CD4 and CD8 T cell frequencies. Broadly, these data indicate impaired GC-derived immunity in immunocompromised individuals and suggest a GC origin for certain humoral and memory B cell responses following mRNA vaccination.

Circulating T cell specific extracellular vesicle profiles in cardiac allograft acute cellular rejection.

There is a critical need for biomarkers of acute cellular rejection (ACR) in organ transplantation. We hypothesized that ACR leads to changes in donor-reactive T cell small extracellular vesicle (sEV) profiles in transplant recipient circulation that match the kinetics of alloreactive T cell activation. In rodent heart transplantation, circulating T cell sEV quantities (P < .0001) and their protein and mRNA cargoes showed time-specific expression of alloreactive and regulatory markers heralding early ACR in allogeneic transplant recipients but not in syngeneic transplant recipients. Next generation sequencing of their microRNA cargoes identified novel candidate biomarkers of ACR, which were validated by stem loop quantitative reverse transcription polymerase chain reaction (n = 10). Circulating T cell sEVs enriched from allogeneic transplant recipients mediated targeted cytotoxicity of donor cardiomyocytes by apoptosis assay (P < .0001). Translation of the concept and EV methodologies to clinical heart transplantation demonstrated similar upregulation of circulating T cell sEV profiles at time points of grade 2 ACR (n = 3 patients). Furthermore, T cell receptor sequencing of T cell sEV mRNA cargo demonstrated expression of T cell clones with intact complementarity determining region 3 signals. These data support the diagnostic potential of T cell sEVs as noninvasive biomarker of ACR and suggest their potential functional roles.

Accuracy of Conflicts in Interest in General Surgical Journals.

OBJECTIVE: To evaluate the accuracy of self-reported conflicts of interest (COIs) for articles published in prominent minimally invasive and general surgical journals. BACKGROUND: Accurate reporting of industry relationships and COIs is crucial for unbiased assessment of a particular study. Despite the enactment of COI laws, such as the Physician Payments Sunshine Act in 2010, prior work suggests that 40-70% of self-reported COIs have discrepancies. METHODS: We utilized three public databases -- Open Payments (USA), Disclosure UK, and Disclosure Australia -- to assess the accuracy of COI disclosures among authors of 918 published articles from these respective countries. Seven journals were utilized to review the COIs for authors of manuscripts published in 2022 - JAMA Surgery, Annals of Surgery, British Journal of Surgery (BJS), Journal of American College of Surgeons (JACS), Surgical Endoscopy, Obesity Surgery, and Surgery for Obesity and Related Diseases (SOARD). RESULTS: Among the analyzed 6206 authors, 5675 belonged to countries of interest: USA (4282), UK (718), and Australia (213). Of these, 774 authors (12.5%) self-reported a conflict of interest in their papers. Overall, only 4055 researchers (69.1%) reported COIs accurately. Authors from the US had the lowest accuracy of reporting COI at 69% as opposed to UK (93%) and Australia (96%). Inaccurate COI reporting was most common in corresponding/senior authors (39%) and least common amongst first authors (18%). Most payments in excess of $50,000 made to authors by an industry sponsor were not disclosed appropriately. CONCLUSIONS: Our study shows that inaccuracy of self-reported COIs in general surgery journals remains high at 31%. While our findings should encourage authors to overreport any possible COI, journals should consider verifying the authors' COI to facilitate more accurate reporting.

Unique model of chronic hypoxia in fetal lambs demonstrates abnormal contrast-enhanced ultrasound brain perfusion.

BACKGROUND: Children with congenital heart disease (CHD) demonstrate long-term neurodevelopmental impairments. We investigated contrast-enhanced ultrasound (CEUS) cerebral perfusion in a fetal animal model exposed to sub-physiologic oxygen at equivalent levels observed in human fetuses with CHD. METHODS: Fifteen fetal lambs [hypoxic animals (n = 9) and normoxic controls (n = 6)] maintained in an extrauterine environment underwent periodic brain CEUS. Perfusion parameters including microvascular flow velocity (MFV), transit time, and microvascular blood flow (MBF) were extrapolated from a standardized plane; regions of interest (ROI) included whole brain, central/thalami, and peripheral parenchymal analyses. Daily echocardiographic parameters and middle cerebral artery (MCA) pulsatility indices (PIs) were obtained. RESULTS: Hypoxic lambs demonstrated decreased MFV, increased transit time, and decreased MBF (p = 0.026, p = 0.016, and p < 0.001, respectively) by whole brain analyses. MFV and transit time were relatively preserved in the central/thalami (p = 0.11, p = 0.08, p = 0.012, respectively) with differences in the peripheral parenchyma (all p < 0.001). In general, cardiac variables did not correlate with cerebral CEUS perfusion parameters. Hypoxic animals demonstrated decreased MCA PI compared to controls (0.65 vs. 0.78, respectively; p = 0.027). CONCLUSION: Aberrations in CEUS perfusion parameters suggest that in environments of prolonged hypoxia, there are regional microvascular differences incompletely characterized by MCA interrogation offering insights into fetal conditions which may contribute to patient outcomes. IMPACT: This work utilizes CEUS to study cerebral microvascular perfusion in a unique fetal animal model subjected to chronic hypoxic conditions equal to fetuses with congenital heart disease. CEUS demonstrates altered parameters with regional differences that are incompletely characterized by MCA Doppler values. These findings show that routine MCA Doppler interrogation may be inadequate in assessing microvascular perfusion differences. To our knowledge, this study is the first to utilize CEUS to assess microvascular perfusion in this model. The results offer insight into underlying conditions and physiological changes which may contribute to known neurodevelopmental impairments in those with congenital heart disease.

Therapeutic Opportunities for Immunoreceptor-Engineered T Cell Therapy for Modulation of Alloimmunity.

Achieving immunosuppression-free immune tolerance to an allograft is one of the central goals of transplantation. In this article, we review recent developments in the fields of T cell-based therapies and T cell engineering using chimeric Ag receptors and their potential for effective and targeted immune modulation of T and B cell activity in an effort to eliminate pre-existing alloantibodies (desensitization) and achieve long-term tolerance. Approaches that span preclinical to early clinical studies in transplantation will be reviewed, with specific emphasis on advances in T cell immunotherapy that have shown promise. Lastly, we conclude with a forward-looking discussion of how T cell-based therapies in other fields of medicine can be potentially applied to solid organ transplantation.

A 3D atlas of functional human brain energetic connectome based on neuropil distribution.

The human brain is energetically expensive, yet the key factors governing its heterogeneous energy distributions across cortical regions to support its diversity of functions remain unexplored. Here, we built up a 3D digital cortical energy atlas based on the energetic costs of all neuropil activities into a high-resolution stereological map of the human cortex with cellular and synaptic densities derived, respectively, from ex vivo histological staining and in vivo PET imaging. The atlas was validated with PET-measured glucose oxidation at the voxel level. A 3D cortical activity map was calculated to predict the heterogeneous activity rates across all cortical regions, which revealed that resting brain is indeed active with heterogeneous neuronal activity rates averaging around 1.2 Hz, comprising around 70% of the glucose oxidation of the cortex. Additionally, synaptic density dominates spatial patterns of energetics, suggesting that the cortical energetics rely heavily on the distribution of synaptic connections. Recent evidence from functional imaging studies suggests that some cortical areas act as hubs (i.e., interconnecting distinct and functionally active regions). An inverse allometric relationship was observed between hub metabolic rates versus hub volumes. Hubs with smaller volumes have higher synapse density, metabolic rate, and activity rates compared to nonhubs. The open-source BrainEnergyAtlas provides a granular framework for exploring revealing design principles in energy-constrained human cortical circuits across multiple spatial scales.

Safety and cost of performing laparoscopic sleeve gastrectomy with same day discharge at a large academic hospital.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is the most common surgical treatment for morbid obesity. While certain specialized ambulatory surgery centers offer LSG on an outpatient basis, patients undergoing LSG at most academic centers are admitted to hospital for initial postoperative convalescence and monitoring. Our institution has begun to offer LSG with same-day discharge (SDD) in select patients. We aimed to compare the perioperative outcomes and costs for patients undergoing LSG with inpatient admission versus SDD. METHODS: All patients enrolled in the SDD program from December 2020 through July 2022 were identified from a prospectively maintained database. Patients enrolled in this pathway were analyzed on an intention-to-treat basis even if ultimately admitted postoperatively. Propensity scoring was used to match these patients 1:1 to those with planned inpatient recovery based on age, BMI, and ASA classification. RESULTS: Seventy-five patients were enrolled in the LSG with SDD program during the study period. Among these, 62 patients (82.7%) had successful immediate postoperative discharge. Reasons for cancelation of planned SDD included anxiety (n = 5), pain (n = 3), nausea (n = 2), and one patient each with hypotension, urinary retention, and bleeding. After matching, there were no differences in age, BMI, or ASA classification in a comparison group of patients with planned inpatient recovery. There were no differences in perioperative complications. There were no readmissions or requirements for outpatient intravenous fluids among patients with SDD, compared to n = 3 (4.0%) and n = 2 (2.7%) in the inpatient cohort, respectively. The total perioperative cost for patients undergoing LSG with planned SDD was 6.8% less than those with inpatient recovery. CONCLUSION: With appropriate protocols, LSG with same-day discharge can safely be performed at large academic surgery centers without increased morbidity or need for additional services in the perioperative period. SDD may be associated with decreased costs and allows for more efficient hospital bed allocation.

Modulation of the gut microbiota engages antigen cross-presentation to enhance antitumor effects of CAR T cell immunotherapy.

Several studies have shown the influence of commensal microbes on T cell function, specifically in the setting of checkpoint immunotherapy for cancer. In this study, we investigated how vancomycin-induced gut microbiota dysbiosis affects chimeric antigen receptor (CAR) T immunotherapy using multiple preclinical models as well as clinical correlates. In two murine tumor models, hematopoietic CD19+-A20 lymphoma and CD19+-B16 melanoma, mice receiving vancomycin in combination with CD19-directed CAR T cell (CART-19) therapy displayed increased tumor control and tumor-associated antigens (TAAs) cross-presentation compared with CART-19 alone. Fecal microbiota transplant from human healthy donors to pre-conditioned mice recapitulated the results obtained in naive gut microbiota mice. Last, B cell acute lymphoblastic leukemia patients treated with CART-19 and exposed to oral vancomycin showed higher CART-19 peak expansion compared with unexposed patients. These results substantiate the role of the gut microbiota on CAR T cell therapy and suggest that modulation of the gut microbiota using vancomycin may improve outcomes after CAR T cell therapy across tumor types.

Impact of Portable Normothermic Machine Perfusion for Liver Transplantation From Adult Deceased Donors.

OBJECTIVE: To assess how liver allografts preserved using portable normothermic machine perfusion (NMP) compare against those that underwent ischemic cold storage (ICS) in the setting of donation after brain death (DBD) and donation after circulatory death (DCD) liver transplantation (LT). BACKGROUND: Compared with conventional ICS, NMP may offer more homeostatic preservation, permit physiological assessment of organ function, and provide opportunities for graft improvement/modification. We report a single-center US experience of liver NMP. METHODS: A single-center, retrospective analysis of collected data on 541 adult whole LTs from 469 DBD donors [NMP (n = 58) vs ICS (n = 411)] and 72 DCD donors [NMP (n = 52) vs ICS (n = 20)] between January 2016 and December 2022. RESULTS: In DBD LT, male sex [odds ratio (95% CI): 1.83 (1.08-3.09)] and >10% macrosteatosis of the donor liver [1.85 (1.10-3.10)] were statistically significant independent risk factors of early allograft dysfunction (EAD). Donor age >40 years and cold ischemia time >7 hours were independent risk factors of reperfusion syndrome (RPS). One-year, 3-year, and 5-year incidences of ischemic cholangiopathy (IC) did not differ significantly in DBD cases between the NMP and ICS cohorts. In DCD LT, NMP was an independent protective factor against EAD [0.11 (0.03-0.46)] and RPS [0.04 (0.01-0.25)]. The incidence of IC in the DCD cases at 1-year and 3-year time points was significantly lower in the NMP cohort (1.9% compared with 20% in the ICS group). CONCLUSIONS: Compared with conventional ICS, NMP can significantly reduce the incidence of EAD, RPS, and IC after DCD LT.

Reusable scrub caps are cost-effective and help reduce the climate footprint of surgery.

BACKGROUND: As the US healthcare sector contributes to 5-10% of national CO2 emissions, with a substantial contribution from surgical services, a collective effort is important to minimize the climate footprint of surgery. Solid plastic waste generated from single-use items in operating rooms is a major contributor to greenhouse gas emissions. To address this problem, we implemented a pilot study to replace single-use scrub caps with reusable caps. METHODS: Ninety-two surgical trainees at the Massachusetts General Hospital, Boston, were provided reusable personalized scrub caps. Over 6 months, their use of the reusable cap was compared with corresponding use of disposable single-use caps. We then used the cost of raw materials, fabric and cap manufacturing, transportation, and end-of-life/waste treatment to perform an economic and environmental burden analysis. RESULTS: After 6 months of reusable scrub cap use, 33 participants (51.6%) reported that due to their use of a reusable scrub cap, their utilization of disposable bouffant or caps had decreased by 76-100%. This was associated with a significant reduction in the use of single-use caps after adjusting for surgical case volume. The carbon footprint of single-use scrub caps was significantly higher than reusable caps during the study period. Reusable scrub cap usage also strongly correlated with substantial reductions in energy consumption and freshwater toxicity. CONCLUSIONS: Reusable personalized cloth scrub caps are cost-effective and can help reduce surgery's carbon footprint by reducing waste generated from disposable scrub cap use. More programs should consider replacing single-use polypropylene caps with reusable scrub caps for their operating room staff.

Contrast-enhanced subharmonic aided pressure estimation for assessment of intracranial pressure in vivo.

BACKGROUND: Intracranial pressure (ICP) monitoring in children currently requires invasive techniques. Subharmonic aided pressure estimation (SHAPE) uses contrast-enhanced ultrasound (CEUS) to measure intravascular and interstitial pressure, but utility in ICP measurements has yet to be explored. OBJECTIVE: The objective of this study was to investigate SHAPE as a novel tool for noninvasive ICP measurements in fetal lambs. MATERIALS AND METHODS: Eighteen fetal lambs at 107-139 days gestational age (term = 145 days) underwent subdural ICP catheter placement. The brain was imaged in the coronal plane in CEUS mode optimized for SHAPE, while infusing an US contrast agent into the fetal circulation. After SHAPE calibration, saline was infused via the subdural catheter to increase ICP. Five-second SHAPE cine clips were obtained at various ICPs. Subharmonic intensity values of the whole brain and thalami were correlated with ICP values using mixed effects linear regression analyses and the strength of the relationship was evaluated by Spearman's rank-order correlation. RESULTS: Forty-nine experiments produced 723 datapoints, including SHAPE intensity values and mean ICP measurements. There was a statistically significant inverse relationship between SHAPE intensity values and ICP measurements in the whole brain and thalami (median rho value - 0.58 and - 0.56, respectively). CONCLUSION: SHAPE intensity values of the brain demonstrate an inverse and statistically significant correlation with in vivo ICP measurements in an animal model.

Data denoising with transfer learning in single-cell transcriptomics.

Single-cell RNA sequencing (scRNA-seq) data are noisy and sparse. Here, we show that transfer learning across datasets remarkably improves data quality. By coupling a deep autoencoder with a Bayesian model, SAVER-X extracts transferable gene-gene relationships across data from different labs, varying conditions and divergent species, to denoise new target datasets.

PTGES3 is a Putative Prognostic Marker in Breast Cancer.

BACKGROUND: The COX/prostaglandin (COX/PG) pathway plays a role in cancer pathogenesis via the production of prostaglandin E2 (PGE2). In breast cancer, the expression patterns of the COX/PG pathway enzymes involved in PGE2 synthesis are not well defined. MATERIALS AND METHODS: Using the Cancer Genome Atlas data, we analyzed the expression patterns of cyclooxygenases, COX1 (PTGS1) and COX2 (PTGS2), and four downstream enzymes of the COX/prostaglandin pathway - PTGS3 (PTGDS), PTGES1, PTGES2 and PTGES3 - in invasive breast cancer. The Clinical Proteomic Tumor Analysis Consortium database was used to determine the expression of these six genes at the protein level. Existing single-cell RNA sequencing data were used to evaluate the expression of the six COX/PG genes in luminal and basal epithelial cells from normal breast tissues. Cox regression Kaplan-Meier adjusted survival analyses were performed to evaluate the association of COX/PG pathway genes in overall survival using the TCGA data. Finally, we utilized the Tumor Immune Estimation Resource to correlate the expression of these six COX/PG genes with tumor infiltrating immune cell number. RESULTS: COX1, COX2 and PTGES3 were significantly upregulated at the protein level in breast cancer compared to normal tissues (P < 0.005). However, only PTGES3 expression was elevated at both the mRNA and protein level in breast cancer (P < 0.0005). PTGES3 is the most highly expressed enzymes within the COX/PG pathway in both luminal and basal epithelial cells in normal breast tissues. Using Cox Regression Kaplan-Meier survival analysis, PTGES3 expression had a significant inverse prognostic association with breast cancer survival [HR >1.43, P = 0.0057]. Elevated PTGES3 expression within the tumor microenvironment significantly correlated with CD8+ T cell abundance, suggesting a possible immunomodulatory role of PTGES3 in the tumor microenvironment. CONCLUSIONS: PTGES3, a terminal synthetase in the COX/prostaglandin pathway, is a putative prognostic marker in breast cancer.

Properties of regulatory B cells regulating B cell targets.

Regulatory B cells (Bregs) have shown promise as anti-rejection therapy applied to organ transplantation. However, less is known about their effect on other B cell populations that are involved in chronic graft rejection. We recently uncovered that naïve B cells, stimulated by TLR ligand agonists, converted into B cells with regulatory properties (Bregs-TLR) that prevented allograft rejection. Here, we examine the granular phenotype and regulatory properties of Breg-TLR cells suppressing B cells. Cocultures of Bregs-TLR with LPS-activated B cells showed a dose-dependent suppression of targeted B cell proliferation. Adoptive transfers of Bregs-TLR induced a decline in antibody responses to antigenically disparate skin grafts. The role of Breg BCR specificity in regulation was assessed using B cell-deficient mice replenished with transgenic BCR (OB1) and TCR (OT-II) lymphocytes of matching antigenic specificity. Results indicated that proliferation of OB1 B cells, mediated through help from CD4+ OT-II cells, was suppressed by OB1 Bregs of similar specificity. Transcriptomic analyses indicated that Bregs-TLR suppression is associated with a block in targeted B cell differentiation controlled by PRDM1 (Blimp1). This work uncovered the regulatory properties of a new brand of Breg cells and provided mechanistic insights into potential applications of Breg therapy in transplantation.

Reciprocal Learning Between Military and Civilian Surgeons: Past and Future Paths for Medical Innovation.

Numerous surgical advances have resulted from exchanges between military and civilian surgeons. As part of the U.S. National Library of Medicine Michael E. DeBakey Fellowship in the History of Medicine, we conducted archival research to shed light on the lessons that civilian surgery has learned from the military system and vice-versa. Several historical case studies highlight the need for immersive programs where surgeons from the military and civilian sectors can gain exposure to the techniques, expertise, and institutional knowledge the other domain provides. Our findings demonstrate the benefits and promise of structured programs to promote reciprocal learning between military and civilian surgery.

Correction: A specific sequence in the genome of respiratory syncytial virus regulates the generation of copy-back defective viral genomes.

[This corrects the article DOI: 10.1371/journal.ppat.1007707.].

A specific sequence in the genome of respiratory syncytial virus regulates the generation of copy-back defective viral genomes.

Defective viral genomes of the copy-back type (cbDVGs) are the primary initiators of the antiviral immune response during infection with respiratory syncytial virus (RSV) both in vitro and in vivo. However, the mechanism governing cbDVG generation remains unknown, thereby limiting our ability to manipulate cbDVG content in order to modulate the host response to infection. Here we report a specific genomic signal that mediates the generation of a subset of RSV cbDVG species. Using a customized bioinformatics tool, we identified regions in the RSV genome frequently used to generate cbDVGs during infection. We then created a minigenome system to validate the function of one of these sequences and to determine if specific nucleotides were essential for cbDVG generation at that position. Further, we created a recombinant virus unable to produce a subset of cbDVGs due to mutations introduced in this sequence. The identified sequence was also found as a site for cbDVG generation during natural RSV infections, and common cbDVGs originated at this sequence were found among samples from various infected patients. These data demonstrate that sequences encoded in the viral genome determine the location of cbDVG formation and, therefore, the generation of cbDVGs is not a stochastic process. These findings open the possibility of genetically manipulating cbDVG formation to modulate infection outcome.

Novel therapeutic opportunities afforded by plasma cell biology in transplantation.

Despite new immunotherapies aimed at B and T cells, plasma cells and their lifelong antibody secretion constitute a major immune barrier to long-term graft survival. In this mini-review, we survey the recent advances that have been made in the biology and immunometabolism of long-lived plasma cells, and outline aspects of plasma cell function that can be exploited for clinical benefit in recipients of solid organ transplants. A handful of ongoing studies are already targeting plasma cells to achieve desensitization and reduce the alloantibody burden in individuals posttransplant. In reviewing the recent strides made in our understanding of the molecular basis of plasma cell survival, we will place our discussions in the context of existing preclinical and clinical studies.

Immune response to influenza vaccination in the elderly is altered by chronic medication use.

BACKGROUND: The elderly patient population is the most susceptible to influenza virus infection and its associated complications. Polypharmacy is common in the aged, who often have multiple co-morbidities. Previous studies have demonstrated that commonly used prescription drugs can have extensive impact on immune defenses and responses to vaccination. In this study, we examined how the dynamics of immune responses to the two influenza A virus strains of the trivalent inactivated influenza vaccine (TIV) can be affected by patient's history of using the prescription drugs Metformin, NSAIDs or Statins. RESULTS: We provide evidence for differential antibody (Ab) production, B-cell phenotypic changes, alteration in immune cell proportions and transcriptome-wide perturbation in individuals with a history of long-term medication use, compared with non-users. We noted a diminished response to TIV in the elderly on Metformin, whereas those on NSAIDs or Statins had higher baseline responses but reduced relative increases in virus-neutralizing Abs (VNAs) or Abs detected by an enzyme-linked immunosorbent assay (ELISA) following vaccination. CONCLUSION: Collectively, our findings suggest novel pathways that might underlie how long-term medication use impacts immune response to influenza vaccination in the elderly. They provide a strong rationale for targeting the medication-immunity interaction in the aged population to improve vaccination responses.