Glycosylation of recombinant adeno-associated virus serotype 6.

Glycosylation of biopharmaceuticals can affect their safety and efficacy. Glycans can occur on recombinant adeno-associated viruses (rAAVs) that are used for gene therapy; however, the types of glycans that attach to rAAVs are controversial. Here, we conducted lectin microarray analyses on six rAAV serotype 6 (rAAV6) preparations that were produced differently. We demonstrate that O-glycans considered to be attached to rAAV6 were recognized by Agaricus bisporus agglutinin (ABA) and that N-glycans were detected in rAAV6 purified without affinity chromatography. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that the N-glycans detected in rAAV6 were derived from host cell proteins. A combination of ABA-based fractionation and LC-MS/MS revealed that rAAV6 was O-glycosylated with the mucin-type glycans, O-GalNAc (Tn antigen), and mono- and di-sialylated Galß1-3GalNAc (T antigen) at S156, T162, T194, and T201 in viral protein (VP) 2 and with O-GlcNAc at T242 in VP3. The mucin-type O-glycosylated rAAV6 particles were 0.1%-1% of total particles. Further physicochemical and biological analyses revealed that mucin-type O-glycosylated rAAV6 had a lower ratio of VP1 to VP2/VP3, resulting in a lower transduction efficiency both in vitro and in vivo compared with rAAV6 without mucin-type O-glycans. This report details conclusive evidence of rAAV glycosylation and its impact on rAAV-based therapeutics.

Peripheral blood biomarkers associated with combination of immune checkpoint blockade plus chemotherapy in NSCLC.

BACKGROUND: Biomarkers predicting clinical outcomes of treating non-small cell lung cancer (NSCLC) with combination of immune checkpoint inhibitors (ICIs) and chemotherapy would be valuable. OBJECTIVE: This study aims to seek predictors of combination of ICI/chemotherapy response in NSCLC patients using peripheral blood samples. METHODS: Patients diagnosed with advanced NSCLC between July 2019 and May 2021 receiving combination of ICI/chemotherapy were included and assessed for partial responses (PR), stable disease (SD) or progressive disease (PD). We measured circulating immune cells, plasma cytokines and chemokines. RESULTS: Nineteen patients were enrolled. The proportions of circulating natural killer (NK) cells within CD45 + cells, programmed death 1 (PD-1) + Tim-3 + T cells within CD4 + cells, and the amount of chemokine C-X-C ligand (CXCL10) in the plasma were significantly elevated in PR relative to SD/PD patients (median 8.1%-vs-2.1%, P= 0.0032; median 1.2%-vs-0.3%, P= 0.0050; and median 122.6 pg/ml-vs-76.0 pg/ml, P= 0.0125, respectively). Patients with 2 or 3 elevated factors had longer progression-free survival than patients with 0 or only one (not reached-vs-5.6 months, P= 0.0002). CONCLUSIONS: We conclude that NK cells, CD4 + PD-1 + Tim-3 + T cells, and CXCL10 levels in pre-treatment peripheral blood may predict the efficacy of combination of ICI/chemotherapy in NSCLC.

Applications and Limitations of Equilibrium Density Gradient Analytical Ultracentrifugation for the Quantitative Characterization of Adeno-Associated Virus Vectors.

Adeno-associated virus (AAV) vectors are produced as a mixture of the desired particle (full particle, FP), which is filled with the designed DNA, product-related impurities such as particle without DNA (empty particle, EP), and aggregates. Cesium chloride or iodixanol equilibrium density gradient ultracentrifugation (DGE-UC) has been used for the purification of AAV vectors. DGE-UC can separate FP from impurities based on the difference in their buoyant densities. Here, we report the applications and limitations of equilibrium density gradient analytical ultracentrifugation (DGE-AUC) using a modern AUC instrument that employs DGE-UC principles for the characterization and quantitation of AAV vectors. We evaluated the quantitative ability of DGE-AUC in comparison with sedimentation velocity AUC (SV-AUC) or band sedimentation AUC (BS-AUC) using AAVs with different DNA lengths and different serotypes. DGE-AUC enabled the accurate quantification of the ratio of FP to EP when the AAV vector primarily contains these particles. Furthermore, we developed a new workflow to identify the components of separated peaks in addition to FP and EP. Ultraviolet absorption spectra obtained by multiwavelength detection can also support peak assignment following component identification. DGE-AUC experiments for AAV vectors have limitations with regard to minor components with low absorption at the detected wavelength or those with a density similar to that of major components of AAV vectors. DGE-AUC is the only analytical method that can evaluate particle density heterogeneity; therefore, SV-AUC or BS-AUC and DGE-AUC are complementary methods for reliable assessment of the purity of AAV vectors.

Optimization of Flow Imaging Microscopy Setting Using Spherical Beads with Optical Properties Similar to Those of Biopharmaceuticals.

Flow imaging microscopy (FIM) is widely used to characterize biopharmaceutical subvisible particles (SVPs). The segmentation threshold, which defines the boundary between the particle and the background based on pixel intensity, should be properly set for accurate SVP quantification. However, segmentation thresholds are often subjectively and empirically set, potentially leading to variations in measurements across instruments and operators. In the present study, we developed an objective method to optimize the FIM segmentation threshold using poly(methyl methacrylate) (PMMA) beads with a refractive index similar to that of biomolecules. Among several candidate particles that were evaluated, 2.5-µm PMMA beads were the most reliable in size and number, suggesting that the PMMA bead size analyzed by FIM could objectively be used to determine the segmentation threshold for SVP measurements. The PMMA bead concentrations measured by FIM were highly consistent with the indicative concentrations, whereas the PMMA bead size analyzed by FIM decreased with increasing segmentation threshold. The optimal segmentation threshold where the analyzed size was closest to the indicative size differed between an instrument with a black-and-white camera and that with a color camera. Inter-instrument differences in SVP concentrations in acid-stressed recombinant adeno-associated virus (AAV) and protein aggregates were successfully minimized by setting an optimized segmentation threshold specific to the instrument. These results reveal that PMMA beads can aid in determining a more appropriate segmentation threshold to evaluate biopharmaceutical SVPs using FIM.

Determination of the optimal connector length to enhance stability of backbone-circularized granulocyte colony-stimulating factor.

Improving protein stability is important for industrial applications, and one promising method for achieving this is backbone circularization. As connector length affects stability, predicting and elucidating a more stable connector length is necessary for development of the backbone circularization method. However, the relationship between connector length and protein stability has not been completely elucidated. Here, we determined the most stable connector length for granulocyte colony-stimulating factor by changing one residue at a time to produce connector length variants and then measuring their thermal stability. Analysis of the local structures obtained from the predicted structures of the circularized variants revealed that an approach using helix length, dihedral backbone angle, and number of unbonded hydrogen bond donors and acceptors is suitable for identifying connector lengths with higher stability.

Antibody responses to second doses of COVID-19 vaccination in lung cancer patients undergoing treatment.

BACKGROUND: Several reports have revealed that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection tends to have more severe outcomes in cancer patients. Although vaccination reduces the risk of severe disease, data on antibody titers achieved by vaccination is scarce in cancer patients. METHODS: We collected 79 blood samples (69 lung cancer patients and 10 control individuals) and conducted an anti-SARS-CoV-2 antibody assay to compare the antibody titer achieved with current treatment. Sixty-eight patients (86%) received the BNT162 mRNA vaccine and 11 (14%) received the mRNA-1273 vaccine. They were categorized according to the current treatment: control individuals without cancer (cohort A), lung cancer patients who were treated with cytotoxic chemotherapy (cohort B), immunotherapy (cohort C), combination of cytotoxic chemotherapy and immunotherapy (cohort D), tyrosine kinase inhibitors (cohort E), and radiation therapy (cohort F). RESULTS: Among 69 lung cancer patients (cohort B-F), 57 (83%) had adenocarcinoma, and 66 (96%) had advanced-stage cancer. In the anti-SARS-CoV-2 antibody assay, the antibody titer was significantly lower in lung cancer patients than in control individuals (p = 0.01). The median antibody titers were 161 AU/ml in control individuals and 59.9 AU/ml in lung cancer patients. CONCLUSIONS: Antibody titers after the second vaccination were lower in cancer patients than those in healthy individuals. Our findings provide essential information for understanding the benefits and necessity of additional vaccination to prevent SARS-CoV-2 infection in lung cancer patients.

Role of thymic stromal lymphopoietin in allergy and beyond.

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that acts on multiple cell lineages, including dendritic cells, T cells, B cells, neutrophils, mast cells, eosinophils and innate lymphoid cells, affecting their maturation, survival and recruitment. It is best known for its role in promoting type 2 immune responses such as in allergic diseases and, in 2021, a monoclonal antibody targeting TSLP was approved for the treatment of severe asthma. However, it is now clear that TSLP has many other important roles in a variety of settings. Indeed, several genetic variants for TSLP are linked to disease severity, and chromosomal alterations in TSLP are common in certain cancers, indicating important roles of TSLP in disease. In this Review, we discuss recent advances in TSLP biology, highlighting how it regulates the tissue environment not only in allergic disease but also in infectious diseases, inflammatory diseases and cancer. Encouragingly, therapies targeting the TSLP pathway are being actively pursued for several diseases.

A special issue of the Australian society for Biophysics.

On behalf of the Australian Society for Biophysics (ASB) and the Editors of this Special Issue, I would like to express our appreciation to Editor-in-Chief, Damien Hall, for arranging the publication of this Special Issue. The ASB is about five times smaller than our sister the Biophysical Society for Japan (BSJ) and tenfold smaller than the US Biophysical Society (USBS), but our meetings are notable because of the encouragement the Society gives to emerging biophysicists. It can be a terrifying experience for a PhD student to have to face a roomful of professors and senior academics, but invariably they appreciate the experience. Another feature of the ASB meetings is the inclusion of contributions from the Asian Pacific region. We now have formal ties with our New Zealand colleagues and our meetings with the BSJ contain joint sessions (see below). In 2020, despite the impact of COVID-19 (see Adam Hill's Commentary), there is a joint session with the University of California Davis. This Special Issue comprises 2 Editorials, 3 Commentaries, and 25 reviews.

Effect of backbone circularization on colloidal stability: Compaction of unfolded structures improves aggregation resistance of granulocyte colony-stimulating factor.

Aggregation of protein therapeutics can lead to immunogenicity and loss of function in vivo. Its effective prevention requires an understanding of the conformational and colloidal stability of protein and the improvement of both. Granulocyte colony-stimulating factor (G-CSF), which is one of the most widely used protein therapeutics, was previously shown to be conformationally stabilized by connecting its N- and C-termini with amide bonds (backbone circularization). In this study, we investigated whether circularization affects the colloidal stability of proteins. Colloidal stability was indirectly assessed by analyzing the aggregation behavior of G-CSF variants using analytical ultracentrifugation (AUC) and small-angle X-ray scattering (SAXS). Consequently, we found that the unfolded structure of circularized G-CSF was more compact than non-circularized G-CSF, and that backbone circularization improved its aggregation resistance against chemical denaturation by guanidine hydrochloride (GdnHCl). The improved aggregation resistance suggests that the expansion tolerance of circularized G-CSF in the unfolded state increased its colloidal stability. Thus, backbone circularization is an excellent method for enhancing the colloidal and the conformational stability of protein with minimal sequence changes. It is therefore expected to be effective in extending the storage stability of protein therapeutics, enhancing their biological stability.

Announcing the call for the Special Issue on "The Australian Society for Biophysics (ASB) - 2021 Meeting".

This Commentary describes a call for submissions for the upcoming Special Issue focused on the research topics presented at the Australian Society of Biophysics (ASB) in 2020 and 2021. Submissions from past and present ASB members who could not attend these meetings are also welcome as contributions to this special issue.

Disease control and objective responsive rates in randomized phase II trials evaluating non-first-line chemotherapy for non-small cell lung cancer: a systematic review of 74 trials.

Although objective response rate and disease control rate are commonly used as primary endpoints of lung cancer trials, it remains unclear whether objective response rate and disease control rate correctly reflect the overall survival in a non-small cell lung cancer phase II trial evaluating a non-first-line chemotherapy. Objective response rate might be easily affected by chance because the small number of patients in each trial achieved complete or partial response in the phase II non-first-line setting. This study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (UMIN000040412). Four databases were searched for eligible trials. A Spearman's rank correlation with hazard ratio of overall survival was calculated each for odds ratio of objective response rate, difference of objective response rate (%), odds ratio of disease control rate, and difference of disease control rate (%). Of 74 eligible trials, 73 reported objective response rate and 68 reported disease control rates. Nine (12%) trials included patients with driver mutation status. Thirteen (18%) and two (3%) RCTs specifically included adenocarcinoma/non-squamous and squamous subtype of non-small cell lung cancer, respectively. The Eastern Cooperative Oncology Group performance status 0-2 (N=41, 55%) and the performance status 0-1 (N=25, 34%) were frequently used performance status criteria. The median number of patients in the two arms was 116 (interquartile range, 82-159). The correlation between trial-level odds ratio of objective response rate and hazard ratio of overall survival was weak (r=-0.29, 95% CI: -0.49 to -0.05, P=0.014). An exploratory subgroup analysis suggested that fewer responders were associated with poorer correlation. Odds ratio of disease control survival (r=-0.53, 95% CI: -0.68 to -0.32, P<0.001) had moderate rank correlations with hazard ratio of overall survival. Instead of objective response rate, disease control rate should be used as the primary endpoint in a randomized phase II trial evaluating non-first-line chemotherapy for non-small cell lung cancer.

Inhaled Corticosteroid and Secondary Glaucoma: A Meta-analysis of 18 Studies.

PURPOSE: Guidelines and systematic reviews frequently warn of inhaled corticosteroid (ICS)-induced glaucoma. However, most of the published studies deny it. METHODS: We performed a systematic review of randomized, cohort, nested-case control, cross-sectional studies by using Meta-analyses of Observational Studies in Epidemiology statement. Four major databases, PubMed, EMBASE, Cochrane Search Manager, and the Web of Science Core Collection as well as meta-analysis were used. Studies comparing incidence, prevalence and intraocular pressure (IOP) between patients who were treated with and without ICSs were included. A random-model meta-analysis was performed using the inverse variance method. RESULTS: Out of 623 studies screened, 18 with 31,665 subjects were finally included. No significant difference between the 2 groups was observed for crude glaucoma incidence (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.86-1.04; P = 0.26; I² = 0%; P for heterogeneity = 0.57) as a primary endpoint, adjusted glaucoma incidence (OR, 0.90; 95% CI, 0.65-1.24; P = 0.64), crude prevalence (OR, 1.82; 95% CI, 0.23-14.19; P = 0.57), adjusted prevalence (OR, 1.22; 95% CI, 0.50-2.96; P = 0.66), IOP change during ICS treatment (mean difference [MD] +0.01 mmHg; 95% CI, -0.19-0.20; P = 0.95), and single measurement IOP (MD +0.37 mmHg; 95% CI, -0.24-0.97; P = 0.23). Time-to-event analysis for glaucoma development as one of the secondary endpoints (adjusted hazard ratio, 0.52; 95% CI, 0.28-0.96) suggested a reverse association between ICS and glaucoma. CONCLUSIONS: The ophthalmological side effects of ICSs, such as glaucoma and intraocular hypertension, should not be exaggerated. TRIAL REGISTRATION: University Hospital Medical Information Network Center Clinical Trial Registry Identifier: UMIN000040351.

Hydroxychloroquine and chloroquine for treatment of coronavirus disease 19 (COVID-19): a systematic review and meta-analysis of randomized and non-randomized controlled trials.

BACKGROUND: Although the US government approved hydroxychloroquine (HCQ) and chloroquine (CQ) for hospitalized coronavirus disease 19 (COVID-19) patients, some studies denied efficacy of HCQ and CQ. We aimed to evaluate HCQ/CQ treatment for COVID-19. METHODS: Five databases were searched on April 15, 2020, without publication date restriction. We followed both Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology statement reporting recommendations. A random-model meta-analysis was conducted to pool odds ratio (OR) and hazard ratio (HR). The quality of evidence for each outcome and the final recommendation was assessed using the GRADE guidelines of the American College of Chest Physicians. RESULTS: We identified four randomized controlled trials (RCTs) and four observational studies with 2,063 COVID-19 cases. All-cause mortality was not affected by the administration of HCQ/CQ [OR: 1.05, 95% confidence interval (CI): 0.53-2.09, P=0.89]. No improvement of viral clearance was found neither by time-to-event analysis (HR: 1.19, 95% CI: 0.74-1.94, P=0.47) nor frequency on day 7 (OR: 1.47, 95% CI: 0.33-6.63, P=0.62). HCQ/CQ treatment increased the risk of the any adverse event with OR of 3.56 (95% CI: 1.62-7.83, P=0.002). CONCLUSIONS: HCQ/CQ failed to decrease the all-cause mortality (very low quality evidence) and did not improve viral clearance (low or very low quality evidence) but increased the risk of any adverse event (moderate quality evidence). Routine administration of HCQ/CQ for COVID-19 patients is not recommended (weak recommendation, Grade 2C).

Thymic stromal lymphopoietin limits primary and recall CD8+ T-cell anti-viral responses.

Thymic stromal lymphopoietin (TSLP) is a cytokine that acts directly on CD4+ T cells and dendritic cells to promote progression of asthma, atopic dermatitis, and allergic inflammation. However, a direct role for TSLP in CD8+ T-cell primary responses remains controversial and its role in memory CD8+ T cell responses to secondary viral infection is unknown. Here, we investigate the role of TSLP in both primary and recall responses in mice using two different viral systems. Interestingly, TSLP limited the primary CD8+ T-cell response to influenza but did not affect T cell function nor significantly alter the number of memory CD8+ T cells generated after influenza infection. However, TSLP inhibited memory CD8+ T-cell responses to secondary viral infection with influenza or acute systemic LCMV infection. These data reveal a previously unappreciated role for TSLP on recall CD8+ T-cell responses in response to viral infection, findings with potential translational implications.

Current national policies for infant universal bacille Calmette-Guérin vaccination were associated with lower mortality from coronavirus disease 2019.

An exciting debate has emerged whether bacille Calmette-Guérin (BCG) vaccination is effective for the coronavirus disease 2019 (COVID-19) pandemic. Some advocated that BCG-vaccinated people are less suffered from the virus because BCG vaccination is recommendedin COVID-19 high burden countries. However, the others objected because this seemingly attractive relationship is explainable with confounding factors. In a multiple regression with 171 countries adjusting socioeconomical and climatic covariates, countries with current universal pediatric BCG policy were associated with 30-fold (95% confidence interval, 17-52) decrease of COVID-19 mortality per population compared to countries without the policy.

[A CASE OF BRONCHIAL ASTHMA IN A YOUNGER PATIENT WITH VOCAL CORD DYSFUNCTION].

We present a case of a 17-year-old woman with a history of bronchial asthma since two years of age. She had daily asthma attacks from the age of fourteen, and the addition of oral corticosteroids and omalizumab to regular inhaled corticosteroid inhalation failed to relieve symptoms. She was referred to our hospital for detailed examination. On admission, physical examination was normal, but she had complained of dyspnea at the round. Monophonic wheezes and stridor were heard over the anterior neck, while no rales were audible over any part of the chest. Laryngoscopy revealed paradoxical movement of the vocal cords, and a diagnosis of vocal cord dysfunction (VCD) was made. The apparent severe asthma symptoms were considered to reflect VCD, and the treatment for bronchial asthma was stepped down without any recurrence of asthma attacks. Although the etiology of the VCD was unknown, VCD is more common in young women, so stress and personality factors are thought to be involved. It has been noted that childhood asthma often improves between childhood and adolescence, but refractory cases have been noted. In intractable bronchial asthma cases, it is necessary to consider the complications of other diseases, such as VCD, and to perform appropriate management.

Lactate dehydrogenase inhibition synergizes with IL-21 to promote CD8+ T cell stemness and antitumor immunity.

Interleukin (IL)-2 and IL-21 dichotomously shape CD8+ T cell differentiation. IL-2 drives terminal differentiation, generating cells that are poorly effective against tumors, whereas IL-21 promotes stem cell memory T cells (TSCM) and antitumor responses. Here we investigated the role of metabolic programming in the developmental differences induced by these cytokines. IL-2 promoted effector-like metabolism and aerobic glycolysis, robustly inducing lactate dehydrogenase (LDH) and lactate production, whereas IL-21 maintained a metabolically quiescent state dependent on oxidative phosphorylation. LDH inhibition rewired IL-2-induced effects, promoting pyruvate entry into the tricarboxylic acid cycle and inhibiting terminal effector and exhaustion programs, including mRNA expression of members of the NR4A family of nuclear receptors, as well as Prdm1 and Xbp1 While deletion of Ldha prevented development of cells with antitumor effector function, transient LDH inhibition enhanced the generation of memory cells capable of triggering robust antitumor responses after adoptive transfer. LDH inhibition did not significantly affect IL-21-induced metabolism but caused major transcriptomic changes, including the suppression of IL-21-induced exhaustion markers LAG3, PD1, 2B4, and TIM3. LDH inhibition combined with IL-21 increased the formation of TSCM cells, resulting in more profound antitumor responses and prolonged host survival. These findings indicate a pivotal role for LDH in modulating cytokine-mediated T cell differentiation and underscore the therapeutic potential of transiently inhibiting LDH during adoptive T cell-based immunotherapy, with an unanticipated cooperative antitumor effect of LDH inhibition and IL-21.