Vaccine-Induced Antibodies that Neutralize Group 1 and Group 2 Influenza A Viruses.

Antibodies capable of neutralizing divergent influenza A viruses could form the basis of a universal vaccine. Here, from subjects enrolled in an H5N1 DNA/MIV-prime-boost influenza vaccine trial, we sorted hemagglutinin cross-reactive memory B cells and identified three antibody classes, each capable of neutralizing diverse subtypes of group 1 and group 2 influenza A viruses. Co-crystal structures with hemagglutinin revealed that each class utilized characteristic germline genes and convergent sequence motifs to recognize overlapping epitopes in the hemagglutinin stem. All six analyzed subjects had sequences from at least one multidonor class, and-in half the subjects-multidonor-class sequences were recovered from >40% of cross-reactive B cells. By contrast, these multidonor-class sequences were rare in published antibody datasets. Vaccination with a divergent hemagglutinin can thus increase the frequency of B cells encoding broad influenza A-neutralizing antibodies. We propose the sequence signature-quantified prevalence of these B cells as a metric to guide universal influenza A immunization strategies.

Rational Design of an Epstein-Barr Virus Vaccine Targeting the Receptor-Binding Site.

Epstein-Barr virus (EBV) represents a major global health problem. Though it is associated with infectious mononucleosis and ∼200,000 cancers annually worldwide, a vaccine is not available. The major target of immunity is EBV glycoprotein 350/220 (gp350) that mediates attachment to B cells through complement receptor 2 (CR2/CD21). Here, we created self-assembling nanoparticles that displayed different domains of gp350 in a symmetric array. By focusing presentation of the CR2-binding domain on nanoparticles, potent neutralizing antibodies were elicited in mice and non-human primates. The structurally designed nanoparticle vaccine increased neutralization 10- to 100-fold compared to soluble gp350 by targeting a functionally conserved site of vulnerability, improving vaccine-induced protection in a mouse model. This rational approach to EBV vaccine design elicited potent neutralizing antibody responses by arrayed presentation of a conserved viral entry domain, a strategy that can be applied to other viruses.

A risk-reward examination of sample multiplexing reagents for single cell RNA-Seq.

Single-cell RNA sequencing (scRNA-Seq) has emerged as a powerful tool for understanding cellular heterogeneity and function. However the choice of sample multiplexing reagents can impact data quality and experimental outcomes. In this study, we compared various multiplexing reagents, including MULTI-Seq, Hashtag antibody, and CellPlex, across diverse sample types such as human peripheral blood mononuclear cells (PBMCs), mouse embryonic brain and patient-derived xenografts (PDXs). We found that all multiplexing reagents worked well in cell types robust to ex vivo manipulation but suffered from signal-to-noise issues in more delicate sample types. We compared multiple demultiplexing algorithms which differed in performance depending on data quality. We find that minor improvements to laboratory workflows such as titration and rapid processing are critical to optimal performance. We also compared the performance of fixed scRNA-Seq kits and highlight the advantages of the Parse Biosciences kit for fragile samples. Highly multiplexed scRNA-Seq experiments require more sequencing resources, therefore we evaluated CRISPR-based destruction of non-informative genes to enhance sequencing value. Our comprehensive analysis provides insights into the selection of appropriate sample multiplexing reagents and protocols for scRNA-Seq experiments, facilitating more accurate and cost-effective studies.

A brave new framework for glioma drug development.

Patients with brain tumours are motivated to participate in clinical trials involving repeat tissue sampling. Normalising the use of neoadjuvant and staged surgical trials necessitates collaboration among patients, regulatory agencies, and researchers. Initial and repetitive tissue sampling plays a crucial role in enhancing our understanding of resistance mechanisms and vulnerabilities in brain tumour therapy. Standardising biopsy techniques and ensuring technical uniformity across institutions are vital for effective interinstitutional collaboration. Although liquid biopsy technologies hold promise, they are not yet ready to replace tissue analysis. Clear communication about the risks and benefits of biopsies is essential, particularly regarding potential postoperative deficits. Changes in mindset and neurosurgical culture are imperative to achieve much needed breakthroughs in the development of new, effective therapies for brain tumours.

A perioperative study of Safusidenib in patients with IDH1-mutated glioma.

This is a single arm, open label perioperative trial to assess the feasibility, pharmacokinetics and pharmacodynamics of treatment with safusidenib following biopsy, and prior to surgical resection in patients with IDH1 mutated glioma who have not received radiation therapy or chemotherapy. Fifteen participants will receive treatment in two parts. First, biopsy followed by one cycle (28 days) of safusidenib, an orally available, small molecular inhibitor of mutated IDH1, then maximal safe resection of the tumor (Part A). Second, after recovery from surgery, safusidenib until disease progression or unacceptable toxicity (Part B). This research will enable objective measurement of biological activity of safusidenib in patients with IDH1 mutated glioma. Anti-tumor activity will be assessed by progression free survival and time to next intervention.Clinical Trial Registration: NCT05577416 (ClinicalTrials.gov).

Adult low-grade gliomas (aLGG) are primary brain cancers, defined by mutations in IDH1 or IDH2. When the IDH gene becomes abnormal (mutated), production of a metabolite that causes cancer cells to grow is increased. These tumors grow slowly but invade the normal functioning brain, making them nearly impossible to cure. The current standard of care treatment includes surgery, followed by radiation therapy and chemotherapy, the timing of which depends on the risk of cancer regrowth. Some patients may be suitable for monitoring with MRI scans alone, however recurrences will inevitably occur. Recently developed targeted mutant IDH inhibitors for aLGG patients may be beneficial both at diagnosis and recurrence. Notably, early treatment prior to radiation therapy and chemotherapy delays growth of aLGG and the need for subsequent radiation therapy and chemotherapy. Nevertheless, most patients will eventually suffer further tumor growth and the optimal timing and sequencing of these therapies remains an area of active research. This research investigates the mutant IDH1 inhibitor safusidenib. The researchers are conducting an innovative clinical trial where patients with aLGG, who have not received radiation therapy or chemotherapy, are treated with safusidenib following a biopsy and prior to surgical removal of their tumor. In this study they investigate whether this trial design is safe and feasible, and how safusidenib works; with the goal to better understand the optimal use of IDH inhibitors for patients with aLGG.

Correlating MRI features with additional genetic markers and patient survival in histological grade 2-3 IDH-mutant astrocytomas.

PURPOSE: The increasing importance of molecular markers for classification and prognostication of diffuse gliomas has prompted the use of imaging features to predict genotype ("radiogenomics"). CDKN2A/B homozygous deletion has only recently been added to the diagnostic paradigm for IDH[isocitrate dehydrogenase]-mutant astrocytomas; thus, associated radiogenomic literature is sparse. There is also little data on whether different IDH mutations are associated with different imaging appearances. Furthermore, given that molecular status is now generally obtained routinely, the additional prognostic value of radiogenomic features is less clear. This study correlated MRI features with CDKN2A/B status, IDH mutation type and survival in histological grade 2-3 IDH-mutant brain astrocytomas. METHODS: Fifty-eight grade 2-3 IDH-mutant astrocytomas were identified, 50 with CDKN2A/B results. IDH mutations were stratified into IDH1-R132H and non-canonical mutations. Background and survival data were obtained. Two neuroradiologists independently assessed the following MRI features: T2-FLAIR mismatch (<25%, 25-50%, >50%), well-defined tumour margins, contrast-enhancement (absent, wispy, solid) and central necrosis. RESULTS: 8/50 tumours with CDKN2A/B results demonstrated homozygous deletion; slightly shorter survival was not significant (p=0.571). IDH1-R132H mutations were present in 50/58 (86%). No MRI features correlated with CDKN2A/B status or IDH mutation type. T2-FLAIR mismatch did not predict survival (p=0.977), but well-defined margins predicted longer survival (HR 0.36, p=0.008), while solid enhancement predicted shorter survival (HR 3.86, p=0.004). Both correlations remained significant on multivariate analysis. CONCLUSION: MRI features did not predict CDKN2A/B homozygous deletion, but provided additional positive and negative prognostic information which correlated more strongly with prognosis than CDKN2A/B status in our cohort.

Moderately hypofractionated versus conventionally fractionated radiation therapy with temozolomide for young and fit patients with glioblastoma: an institutional experience and meta-analysis of literature.

PURPOSE: Shorter hypofractionated radiation therapy (HF-RT) schedules may have radiobiological, patient convenience and healthcare resource advantages over conventionally fractionated radiation therapy (CF-RT) in glioblastoma (GBM). We report outcomes of young, fit GBM patients treated with HF-RT and CF-RT during the COVID-19 pandemic, and a meta-analysis of HF-RT literature in this patient subgroup. METHODS: Hospital records of patients with IDH-wildtype GBM treated with HF-RT (50 Gy/20 fractions) and CF-RT (60 Gy/30 fractions) between January 2020 and September 2021 were reviewed. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Univariable analysis was performed using Cox regression analysis. A systematic search and meta-analysis of studies from January 2000 to January 2022 was performed. RESULTS: 41 patients were treated (HF-RT:15, CF-RT:26). For both HF-RT and CF-RT groups, median age was 58 years and 80-90% were ECOG 0-1. There were more methylated tumours in the HF-RT group. All patients received concurrent/adjuvant temozolomide. At 19.2 months median follow-up, median OS was 19.8 months and not-reached for HF-RT and CF-RT (p = 0.5), and median PFS was 7.7 and 5.8 months, respectively (p = 0.8). HF-RT or CF-RT did not influence OS/PFS on univariable analysis. Grade 3 radionecrosis rate was 6.7% and 7.7%, respectively. 15 of 1135 studies screened from a systematic search were eligible for meta-analysis. For studies involving temozolomide, pooled median OS and PFS with HF-RT were 17.5 and 9.9 months (927 and 862 patients). Studies using shortened HF-RT schedules reported 0-2% Grade 3 radionecrosis rates. CONCLUSION: HF-RT may offer equivalent outcomes and reduce treatment burden compared to CF-RT in young, fit GBM patients.

PALVEN: phase Ib trial of palbociclib, letrozole and venetoclax in estrogen receptor- and BCL2-positive advanced breast cancer.

The addition of a CDK4/6 inhibitor to endocrine therapy improves progression-free and overall survival in women with metastatic estrogen receptor-positive breast cancer. In that setting, CDK4/6 inhibitors induce a potent cell-cycle arrest (which may be accompanied by tumor senescence) but fail to induce apoptotic cell death. Venetoclax is a potent inhibitor of BCL2, a pro-survival protein overexpressed in the majority of estrogen receptor-positive cancers. Pre-clinical findings indicate that venetoclax augments tumor response to the CDK4/6 inhibitor palbociclib by triggering apoptosis, including in senescent cells. The PALVEN phase Ib trial will further examine this finding. The primary objective is to identify the maximum tolerated dose and determine the recommended phase II dose for palbociclib, letrozole and venetoclax combination therapy. Clinical Trial Registration: NCT03900884 (ClinicalTrials.gov).

The current 'gold standard' treatment for estrogen receptor-positive, HER2-negative metastatic breast cancer is endocrine therapy with a CDK4/6 inhibitor. This combination improves tumor response and patient outcomes, primarily by reducing tumor cell growth. Paradoxically, less killing of tumor cells is observed in the presence of a CDK4/6 inhibitor. The authors hypothesize that co-treatment with venetoclax, an inhibitor of the BCL2 survival protein, will help trigger tumor death, thereby further improving tumor responses and patient outcomes. As a first step, combination therapy comprising letrozole, palbociclib and venetoclax will be tested in a phase I trial to identify the recommended doses for subsequent studies.

Carboplatin dosing in the era of IDMS-creatinine; the Cockroft-Gault formula no longer provides a sufficiently accurate estimate of glomerular filtration rate for routine use in clinical care.

BACKGROUND: Glomerular filtration rate (GFR) measured by Chromium-51-EDTA excretion (51Cr-GFR) is considered the gold standard of renal function assessment, but serum creatinine in the Cockcroft-Gault (CG) formula is routinely used to estimate GFR for carboplatin dosing. Serum creatinine measured by isotope-dilution-mass-spectrometry (IDMS) can generate spuriously high GFR estimates when used in the CG formula. We hypothesized that GFR calculated using IDMS-creatinine in the CG formula (CG-GFR) exposes patients to inaccurate carboplatin dosing. METHODS: This is a multicenter retrospective study of patients who had a 51Cr-GFR assessment for malignant or non-malignant indications, with a matched CG-GFR. Carboplatin dose based on 51Cr-GFR at AUC5 was used as the reference. RESULTS: 550 patients were analyzed, median age 62 (19-90), 64% female. Indication for GFR evaluation: malignancy (85%), assessment for live kidney donation (12%), other (3%). Median ratio of CG-GFR: 51Cr-GFR 1.04 (0.43-3.38); <0.8 in 72 patients (13%), >1.2 in 180 patients (33%). Despite capping of CG-GFR at 125 mL/min, dosing according to AUC6 would have resulted in 18% of patients being underdosed and 23% overdosed by >100 mg compared to 51Cr-GFR. Subgroup analysis identified BMI (>35, MPE 39%), gender (female MPE 15%), GFR indication (malignancy MPE 11%) as risk factors for overestimate of CG-GFR, and BMI < 20 for underestimate (MPE -3.5%). CONCLUSIONS: The convention of considering AUC5 carboplatin based on 51Cr-GFR, and AUC6 carboplatin based on CG-GFR as equivalent is invalid and should be abandoned. When 51Cr-GFR is unavailable, capping CG-GFR at 125 mL/min is recommended.

Self-assembling influenza nanoparticle vaccines elicit broadly neutralizing H1N1 antibodies.

Influenza viruses pose a significant threat to the public and are a burden on global health systems. Each year, influenza vaccines must be rapidly produced to match circulating viruses, a process constrained by dated technology and vulnerable to unexpected strains emerging from humans and animal reservoirs. Here we use knowledge of protein structure to design self-assembling nanoparticles that elicit broader and more potent immunity than traditional influenza vaccines. The viral haemagglutinin was genetically fused to ferritin, a protein that naturally forms nanoparticles composed of 24 identical polypeptides. Haemagglutinin was inserted at the interface of adjacent subunits so that it spontaneously assembled and generated eight trimeric viral spikes on its surface. Immunization with this influenza nanoparticle vaccine elicited haemagglutination inhibition antibody titres more than tenfold higher than those from the licensed inactivated vaccine. Furthermore, it elicited neutralizing antibodies to two highly conserved vulnerable haemagglutinin structures that are targets of universal vaccines: the stem and the receptor binding site on the head. Antibodies elicited by a 1999 haemagglutinin-nanoparticle vaccine neutralized H1N1 viruses from 1934 to 2007 and protected ferrets from an unmatched 2007 H1N1 virus challenge. This structure-based, self-assembling synthetic nanoparticle vaccine improves the potency and breadth of influenza virus immunity, and it provides a foundation for building broader vaccine protection against emerging influenza viruses and other pathogens.

A phase I trial to determine safety and pharmacokinetics of ASLAN002, an oral MET superfamily kinase inhibitor, in patients with advanced or metastatic solid cancers.

Background The MET tyrosine kinase and its ligand, hepatocyte growth factor (HGF) also known as scatter factor, are associated with tumourigenesis and metastasis by promotion of scattering, proliferation, angiogenesis, motility and invasion. ASLAN-002 is a potent inhibitor of MET as well as related kinases. A phase I dose escalation study was conducted to determine the safety and pharmacokinetics of ASLAN-002 in patients with advanced cancer. Methods Patients with advanced or metastatic solid tumours, who had progressed on standard therapy or for whom standard therapy was not known, were administered ASLAN-002 orally. The starting dose was 100 mg once daily (QD) with subsequent cohorts to receive doses of 200 mg QD, 300 mg QD, 450 mg QD, 600 mg QD, 300 mg twice daily (BID), 450 mg BID, and 600 mg BID. Results Forty patients were included across 7 dose cohorts. Cohort 8 (600 mg BID) was not opened due to the lack of appreciable pharmacokinetic (PK) differences between 300 mg BID and 450 mg BID and higher incidences of grade 3 or 4 adverse events (AE) in Cohort 7 (450 mg BID). Fifteen patients (37.5%) experienced a grade 3 or 4 AE. The most commonly reported AEs were nausea (55%), fatigue (47.5%) and constipation (30%). One dose limiting toxicity (DLT) of atrial fibrillation was observed with 450 mg BID. Conclusions ASLAN-002 is well tolerated at 300 mg BID and is the recommended dose for future phase II studies (RP2D). Clinical Trials Registry Number: NCT01721148 .

Structural and genetic basis for development of broadly neutralizing influenza antibodies.

Influenza viruses take a yearly toll on human life despite efforts to contain them with seasonal vaccines. These viruses evade human immunity through the evolution of variants that resist neutralization. The identification of antibodies that recognize invariant structures on the influenza haemagglutinin (HA) protein have invigorated efforts to develop universal influenza vaccines. Specifically, antibodies to the highly conserved stem region of HA neutralize diverse viral subtypes. These antibodies largely derive from a specific antibody gene, heavy-chain variable region IGHV1-69, after limited affinity maturation from their germline ancestors, but how HA stimulates naive B cells to mature and induce protective immunity is unknown. To address this question, we analysed the structural and genetic basis for their engagement and maturation into broadly neutralizing antibodies. Here we show that the germline-encoded precursors of these antibodies act as functional B-cell antigen receptors (BCRs) that initiate subsequent affinity maturation. Neither the germline precursor of a prototypic antibody, CR6261 (ref. 3), nor those of two other natural human IGHV1-69 antibodies, bound HA as soluble immunoglobulin-G (IgG). However, all three IGHV1-69 precursors engaged HA when the antibody was expressed as cell surface IgM. HA triggered BCR-associated tyrosine kinase signalling by germline transmembrane IgM. Recognition and virus neutralization was dependent solely on the heavy chain, and affinity maturation of CR6261 required only seven amino acids in the complementarity-determining region (CDR) H1 and framework region 3 (FR3) to restore full activity. These findings provide insight into the initial events that lead to the generation of broadly neutralizing antibodies to influenza, informing the rational design of vaccines to elicit such antibodies and providing a model relevant to other infectious diseases, including human immunodeficiency virus/AIDS. The data further suggest that selected immunoglobulin genes recognize specific protein structural 'patterns' that provide a substrate for further affinity maturation.

H5N1 Vaccine-Elicited Memory B Cells Are Genetically Constrained by the IGHV Locus in the Recognition of a Neutralizing Epitope in the Hemagglutinin Stem.

Because of significant viral diversity, vaccines that elicit durable and broad protection against influenza have been elusive. Recent research has focused on the potential of highly conserved regions of the viral hemagglutinin (HA) as targets for broadly neutralizing Ab responses. Abs that bind the highly conserved stem or stalk of HA can be elicited by vaccination in humans and animal models and neutralize diverse influenza strains. However, the frequency and phenotype of HA stem-specific B cells in vivo remain unclear. In this article, we characterize HA stem-specific B cell responses following H5N1 vaccination and describe the re-expansion of a pre-existing population of memory B cells specific for stem epitopes. This population uses primarily, but not exclusively, IGHV1-69-based Igs for HA recognition. However, within some subjects, allelic polymorphism at the ighv1-69 locus can limit IGHV1-69 immunodominance and may reduce circulating frequencies of stem-reactive B cells in vivo. The accurate definition of allelic selection, recombination requirements, and ontogeny of neutralizing Ab responses to influenza will aid rational influenza vaccine design.

Use of vemurafenib in a patient unable to swallow whole.

The treatment landscape for metastatic melanoma has increased dramatically in the past five years, with the pivotal discovery of activating BRAF mutations in half of all melanomas spurring the development for effective treatments that target mitogen-activated protein kinase (RAS/RAF/MEK/ERK) pathway. Vemurafenib, a selective mutant BRAF Val600 inhibitor, results in striking tumour responses and a survival advantage over conventional chemotherapy. We present here the case of a 38-year-old woman with metastatic BRAFV600E mutant melanoma and a severe tablet phobia, who was found to have been crushing and/or chewing her vemurafenib tablets. In this case, she attained a partial response and significant clinical benefit, albeit temporarily.

Patient-derived xenograft models of breast cancer and their predictive power.

Despite advances in the treatment of patients with early and metastatic breast cancer, mortality remains high due to intrinsic or acquired resistance to therapy. Increased understanding of the genomic landscape through massively parallel sequencing has revealed somatic mutations common to specific subtypes of breast cancer, provided new prognostic and predictive markers, and highlighted potential therapeutic targets. Evaluating new targets using established cell lines is limited by the inexact correlation between responsiveness observed in cell lines versus that elicited in the patient. Patient-derived xenografts (PDXs) generated from fresh tumor specimens recapitulate the diversity of breast cancer and reflect histopathology, tumor behavior, and the metastatic properties of the original tumor. The high degree of genomic preservation evident across primary tumors and their matching PDXs over serial passaging validate them as important preclinical tools. Indeed, there is accumulating evidence that PDXs can recapitulate treatment responses of the parental tumor. The finding that tumor engraftment is an independent and poor prognostic indicator of patient outcome represents the first step towards personalized medicine. Here we review the utility of breast cancer PDX models to study the clonal evolution of tumors and to evaluate novel therapies and drug resistance.

Coinfection with Streptococcus pneumoniae modulates the B cell response to influenza virus.

Pathogen-specific antibodies (Abs) protect against respiratory infection with influenza A virus (IAV) and Streptococcus pneumoniae and are the basis of effective vaccines. Sequential or overlapping coinfections with both pathogens are common, yet the impact of coinfection on the generation and maintenance of Ab responses is largely unknown. We report here that the B cell response to IAV is altered in mice coinfected with IAV and S. pneumoniae and that this response differs, depending on the order of pathogen exposure. In mice exposed to S. pneumoniae prior to IAV, the initial virus-specific germinal center (GC) B cell response is significantly enhanced in the lung-draining mediastinal lymph node and spleen, and there is an increase in CD4(+) T follicular helper (TFH) cell numbers. In contrast, secondary S. pneumoniae infection exaggerates early antiviral antibody-secreting cell formation, and at later times, levels of GCs, TFH cells, and antiviral serum IgG are elevated. Mice exposed to S. pneumoniae prior to IAV do not maintain the initially robust GC response in secondary lymphoid organs and exhibit reduced antiviral serum IgG with diminished virus neutralization activity a month after infection. Our data suggest that the history of pathogen exposures can critically affect the generation of protective antiviral Abs and may partially explain the differential susceptibility to and disease outcomes from IAV infection in humans. Importance: Respiratory tract coinfections, specifically those involving influenza A viruses and Streptococcus pneumoniae, remain a top global health burden. We sought to determine how S. pneumoniae coinfection modulates the B cell immune response to influenza virus since antibodies are key mediators of protection.

Flow cytometry reveals that H5N1 vaccination elicits cross-reactive stem-directed antibodies from multiple Ig heavy-chain lineages.

UNLABELLED: An understanding of the antigen-specific B-cell response to the influenza virus hemagglutinin (HA) is critical to the development of universal influenza vaccines, but it has not been possible to examine these cells directly because HA binds to sialic acid (SA) on most cell types. Here, we use structure-based modification of HA to isolate HA-specific B cells by flow cytometry and characterize the features of HA stem antibodies (Abs) required for their development. Incorporation of a previously described mutation (Y98F) to the receptor binding site (RBS) causes HA to bind only those B cells that express HA-specific Abs, but it does not bind nonspecifically to B cells, and this mutation has no effect on the binding of broadly neutralizing Abs to the RBS. To test the specificity of the Y98F mutation, we first demonstrated that previously described HA nanoparticles mediate hemagglutination and then determined that the Y98F mutation eliminates this activity. Cloning of immunoglobulin genes from HA-specific B cells isolated from a single human subject demonstrates that vaccination with H5N1 influenza virus can elicit B cells expressing stem monoclonal Abs (MAbs). Although these MAbs originated mostly from the IGHV1-69 germ line, a reasonable proportion derived from other genes. Analysis of stem Abs provides insight into the maturation pathways of IGVH1-69-derived stem Abs. Furthermore, this analysis shows that multiple non-IGHV1-69 stem Abs with a similar neutralizing breadth develop after vaccination in humans, suggesting that the HA stem response can be elicited in individuals with non-stem-reactive IGHV1-69 alleles. IMPORTANCE: Universal influenza vaccines would improve immune protection against infection and facilitate vaccine manufacturing and distribution. Flu vaccines stimulate B cells in the blood to produce antibodies that neutralize the virus. These antibodies target a protein on the surface of the virus called HA. Flu vaccines must be reformulated annually, because these antibodies are mostly specific to the viral strains used in the vaccine. But humans can produce broadly neutralizing antibodies. We sought to isolate B cells whose genes encode influenza virus antibodies from a patient vaccinated for avian influenza. To do so, we modified HA so it would bind only the desired cells. Sequencing the antibody genes of cells marked by this probe proved that the patient produced broadly neutralizing antibodies in response to the vaccine. Many sequences obtained had not been observed before. There are more ways to generate broadly neutralizing antibodies for influenza virus than previously thought.

Broadly neutralizing human antibody that recognizes the receptor-binding pocket of influenza virus hemagglutinin.

Seasonal antigenic drift of circulating influenza virus leads to a requirement for frequent changes in vaccine composition, because exposure or vaccination elicits human antibodies with limited cross-neutralization of drifted strains. We describe a human monoclonal antibody, CH65, obtained by isolating rearranged heavy- and light-chain genes from sorted single plasma cells, coming from a subject immunized with the 2007 trivalent influenza vaccine. The crystal structure of a complex of the hemagglutinin (HA) from H1N1 strain A/Solomon Islands/3/2006 with the Fab of CH65 shows that the tip of the CH65 heavy-chain complementarity determining region 3 (CDR3) inserts into the receptor binding pocket on HA1, mimicking in many respects the interaction of the physiological receptor, sialic acid. CH65 neutralizes infectivity of 30 out of 36 H1N1 strains tested. The resistant strains have a single-residue insertion near the rim of the sialic-acid pocket. We conclude that broad neutralization of influenza virus can be achieved by antibodies with contacts that mimic those of the receptor.

Plasma ctDNA liquid biopsy of IDH1, TERTp, and EGFRvIII mutations in glioma.

Background: Circulating tumor DNA has emerging clinical applications in several cancers; however, previous studies have shown low sensitivity in glioma. We investigated if 3 key glioma gene mutations IDH1, TERTp, and EGFRvIII could be reliably detected in plasma by droplet digital polymerase chain reaction (ddPCR) thereby demonstrating the potential of this technique for glioma liquid biopsy. Methods: We analyzed 110 glioma patients from our biobank with a total of 359 plasma samples (median 4 samples per patient). DNA was isolated from plasma and analyzed for IDH1, TERTp, and EGFRvIII mutations using ddPCR. Results: Total cfDNA was significantly associated with tumor grade, tumor volume, and both overall and progression-free survival for all gliomas as well as the grade 4 glioblastoma subgroup, but was not reliably associated with changes in tumor volume/progression during the patients' postoperative time course. IDH1 mutation was detected with 84% overall sensitivity across all plasma samples and 77% in the preoperative samples alone; however, IDH1 mutation plasma levels were not associated with tumor progression or survival. IDH1m plasma levels were not associated with pre- or postsurgery progression or survival. The TERTp C228T mutation was detected in the plasma ctDNA in 88% but the C250T variant in only 49% of samples. The EGFRvIII mutation was detected in plasma in 5 out of 7 patients (71%) with tissue EGFRvIII mutations in tumor tissue. Conclusions: Plasma ctDNA mutations detected with ddPCR provide excellent diagnostic sensitivity for IDH1, TERTp-C228T, and EGFRvIII mutations in glioma patients. Total cfDNA may also assist with prognostic information. Further studies are needed to validate these findings and the clinical role of ctDNA in glioma.