Certolizumab

Certolizumab is a Fab fragment of a humanized monoclonal antibody against tumor necrosis factor-alpha (TNF-alpha). Differing from the other TNF-alpha inhibitors due to the absence of Fc fragment and pegylation, it binds to both the soluble and transmembrane forms of TNF-alpha, creating a strong TNF-alpha blockage. Previously approved for psoriatic arthritis, certolizumab received another approval from FDA in 2018 for the treatment of moderate to severe chronic plaque psoriasis that does not respond to conventional systemic treatments or for which these treatments are contraindicated. Administered via subcutaneous injections, certolizumab also has a low-dose option for patients weighing less than 90 kg. Certolizumab is considered a safe biological drug that can be preferred during pregnancy and lactation.Copyright © 2022 by Turkish Society of Dermatology and Venereology.

Intentional Taxus Baccata Ingestion Presenting with Cardiogenic Shock and Ventricular Tachycardia

Background The prevalence of anxiety and depression has increased following the COVID pandemic. Young women are disproportionally at risk of suicidal behaviors. Ingestion of Taxus baccata (English Yew) may lead to cardiotoxicity and death. Intoxication is known to be resistant to standard treatments with no effective antidotes. Case A 20-year-old female with a history of major depressive disorder presented to our emergency department unresponsive in pulseless ventricular tachycardia (VT) (figure 1A). She underwent CPR and achieved ROSC, however, was persistently hypotensive despite multiple pressors and was subsequently placed on VA ECMO. Review of a home journal revealed a plan to ingest 50 grams of Yew with suicidal intent. Decision-making Taxoids have been reported to have similar properties to digoxin and therefore digoxin-specific FAB antibodies were administered. She was also started on amiodarone and lidocaine for management of VT. After 3 hours she converted into sinus rhythm and had no further episodes of VT. Her clinical course was complicated by severe LV dysfunction and dilation while on VA-ECMO necessitating placement of an LV impella. By day three, all mechanical support was weaned off and she had normalization of her EF. Patient was discharged to an inpatient psychiatry facility on day 7 of hospitalization. Conclusion Ingestion of English Yew with suicidal intent is rare but may cause cardiogenic shock and VT requiring aggressive hemodynamic support until the toxin is metabolized. [Formula presented]Copyright © 2023 American College of Cardiology Foundation

PEGylation Prolongs the Half-Life of Equine Anti-SARS-CoV-2 Specific F(ab')2.

Therapeutic antibodies-F(ab')2 obtained from hyperimmune equine plasma could treat emerging infectious diseases rapidly because of their high neutralization activity and high output. However, the small-sized F(ab')2 is rapidly eliminated by blood circulation. This study explored PEGylation strategies to maximize the half-life of equine anti-SARS-CoV-2 specific F(ab')2. Equine anti-SARS-CoV-2 specific F(ab')2 were combined with 10 KDa MAL-PEG-MAL in optimum conditions. Specifically, there were two strategies: Fab-PEG and Fab-PEG-Fab, F(ab')2 bind to a PEG or two PEG, respectively. A single ion exchange chromatography step accomplished the purification of the products. Finally, the affinity and neutralizing activity was evaluated by ELISA and pseudovirus neutralization assay, and ELISA detected the pharmacokinetic parameters. The results displayed that equine anti-SARS-CoV-2 specific F(ab')2 has high specificity. Furthermore, PEGylation F(ab')2-Fab-PEG-Fab had a longer half-life than specific F(ab')2. The serum half-life of Fab-PEG-Fab, Fab-PEG, and specific F(ab')2 were 71.41 h, 26.73 h, and 38.32 h, respectively. The half-life of Fab-PEG-Fab was approximately two times as long as the specific F(ab')2. Thus far, PEGylated F(ab')2 has been prepared with high safety, high specificity, and a longer half-life, which could be used as a potential treatment for COVID-19.

Single domain antibodies derived from ancient animals as broadly neutralizing agents for SARS-CoV-2 and other coronaviruses.

With severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as an emergent human virus since December 2019, the world population is susceptible to coronavirus disease 2019 (COVID-19). SARS-CoV-2 has higher transmissibility than the previous coronaviruses, associated by the ribonucleic acid (RNA) virus nature with high mutation rate, caused SARS-CoV-2 variants to arise while circulating worldwide. Neutralizing antibodies are identified as immediate and direct-acting therapeutic against COVID-19. Single-domain antibodies (sdAbs), as small biomolecules with non-complex structure and intrinsic stability, can acquire antigen-binding capabilities comparable to conventional antibodies, which serve as an attractive neutralizing solution. SARS-CoV-2 spike protein attaches to human angiotensin-converting enzyme 2 (ACE2) receptor on lung epithelial cells to initiate viral infection, serves as potential therapeutic target. sdAbs have shown broad neutralization towards SARS-CoV-2 with various mutations, effectively stop and prevent infection while efficiently block mutational escape. In addition, sdAbs can be developed into multivalent antibodies or inhaled biotherapeutics against COVID-19.

Passive immunization with equine RBD-specific Fab protects K18-hACE2-mice against Alpha or Beta variants of SARS-CoV-2.

Emergence of variants of concern (VOC) during the COVID-19 pandemic has contributed to the decreased efficacy of therapeutic monoclonal antibody treatments for severe cases of SARS-CoV-2 infection. In addition, the cost of creating these therapeutic treatments is high, making their implementation in low- to middle-income countries devastated by the pandemic very difficult. Here, we explored the use of polyclonal EpF(ab')2 antibodies generated through the immunization of horses with SARS-CoV-2 WA-1 RBD conjugated to HBsAg nanoparticles as a low-cost therapeutic treatment for severe cases of disease. We determined that the equine EpF(ab')2 bind RBD and neutralize ACE2 receptor binding by virus for all VOC strains tested except Omicron. Despite its relatively quick clearance from peripheral circulation, a 100µg dose of EpF(ab')2 was able to fully protect mice against severe disease phenotypes following intranasal SARS-CoV-2 challenge with Alpha and Beta variants. EpF(ab')2 administration increased survival while subsequently lowering disease scores and viral RNA burden in disease-relevant tissues. No significant improvement in survival outcomes or disease scores was observed in EpF(ab')2-treated mice challenged using the Delta variant at 10µg or 100µg doses. Overall, the data presented here provide a proof of concept for the use of EpF(ab')2 in the prevention of severe SARS-CoV-2 infections and underscore the need for either variant-specific treatments or variant-independent therapeutics for COVID-19.

THE BIG IMPACT OF SMALL CHANGES IN NARROW THERAPEUTIC INDEX DRUGS

CASE: An 84-year-old woman with atrial fibrillation on Digoxin presented with acute onset of confusion associated with a week history of abdominal pain, vomiting, and poor fluid intake. A few days prior, Amiodarone was added to her drug regimen which included Lasix. Additionally, she received the COVID-19 booster vaccine which led to a viral-like syndrome resulting in dehydration. The patient was afebrile, normotensive, but bradycardic. EKG showed a prolonged PR interval and scooped ST segments. Labs showed hyperkalemia, pre-renal acute kidney injury (AKI), and a Digoxin level of 4.3 ng/mL (therapeutic range: 0.8-2.0 ng/mL). Digoxin and Lasix were held and Digoxin antidote, Digibind, was administered with normalizing heart rate, potassium, and clinical improvement. IMPACT/DISCUSSION: Digoxin is used to slow conduction in atrial fibrillation and increase cardiac contractility in heart failure. It inhibits the membrane sodium-potassium-adenosine triphosphatase pump (Na/K ATPase), resulting in increased cytosolic calcium and subsequent cardiac contractility and automaticity. In turn, this can also cause premature ventricular contractions and tachycardia. In the carotid sinus, increased baroreceptor firing and subsequent increased vagal tone occurs which can cause bradycardia, atrioventricular blocks, hypotension, and GI symptoms. In skeletal muscle, hyperkalemia can result due to the abundance of Na/K ATPase pumps. Digoxin has a narrow therapeutic index with serum levels easily affected by many commonly prescribed drugs by way of decreasing renal clearance, inhibiting P-glycoprotein, and inducing secondary electrolyte disturbances. That said, drug dosing should be individualized with close monitoring to avoid potentially life-threatening effects that may result with even mildly increased digoxin levels. Acute toxicity manifests as non-specific GI, and neurologic symptoms (confusion, lethargy, visual changes), hyperkalemia, and brady or tachy-arrhythmias. Treatment is with digoxin specific fragment antigen binding (Fab) antibody, Digibind, which binds digoxin, inactivating it within 6-8 hours. Postadministration, digoxin serum testing cannot distinguish free verse bound drug;therefore, drug levels remain elevated for days to weeks until the FabDigoxin complex is excreted. In the case above, the viral-like-syndrome after the booster vaccine with subsequent AKI secondary to dehydration likely precipitated Digoxin toxicity. Accompanying drug interactions of diuretics causing dehydration and hypokalemia, P-glycoprotein inhibitors (Amiodarone, Verapamil, Diltiazem, Quinidine), and ACE inhibitors can further worsen renal clearance and culminate in Digoxin toxicity. CONCLUSION: Given Digoxin's narrow therapeutic index, small clinical changes such as post COVID-19 vaccine flu-like symptoms, dehydration, and medication changes can manifest drug toxicity. Therefore, attentive monitoring of accompanying comorbidities and drug interactions is imperative at preventing catastrophic toxic effects.

Hybridoma technology: is it still useful?

The isolation of single monoclonal antibodies (mAbs) against a given antigen was only possible with the introduction of the hybridoma technology, which is based on the fusion of specific B lymphocytes with myeloma cells. Since then, several mAbs were described for therapeutic, diagnostic, and research purposes. Despite being an old technique with low complexity, hybridoma-based strategies have limitations that include the low efficiency on B lymphocyte-myeloma cell fusion step, and the need to use experimental animals. In face of that, several methods have been developed to improve mAb generation, ranging from changes in hybridoma technique to the advent of completely new technologies, such as the antibody phage display and the single B cell antibody ones. In this review, we discuss the hybridoma technology along with emerging mAb isolation approaches, taking into account their advantages and limitations. Finally, we explore the usefulness of the hybridoma technology nowadays.

A BRIEF SYNOPSIS OF MONOCLONAL ANTIBODY FOR THE TREATMENT OF VARIOUS GROUPS OF DISEASES.

Monoclonal antibodies (mAbs) are increasingly being prescribed to patients and investigated in the field of medicine and research. This class of medication is unique due to its ability to be engineered into targeting a specific receptor. Numerous studies and reviews have reported the efficacy, potency, and clinical usage of mAbs in the treatment of a variety of diseases ranging from autoimmune disorders to malignant cancers. However, very few publications classify and provide a brief synopsis of mAbs that includes their pharmacological profiles. mechanisms of action, uses, and side effects in a concise manner. Therefore, this review aims to classify the current mAbs drugs used in clinical practice according to system diseases by providing a brief summary for each of them. For example, regarding cardiovascular disorders, mAbs such as Abciximab, Bevacizumab, and Digoxin Immune Fab will be reviewed. Denosumab, used to treat musculoskeletal disorders, will be also discussed. In addition, mAbs such as Adalimumab, Eculizumab, Natalizumab used in autoimmune disorders and Alemtuzumab, Trastuzumab, Cetuximab, and Rituximab that are prescribed for tumors will be reviewed. Finally, we shall discuss two mAbs that are IL-6 antagonists, Tocilizumab and Siltuximab, which are in ongoing clinical trials as potential treatments of COVID-19. The mAbs have profound benefits against chronic and malignant conditions, and the overall purpose of this review is to illustrate the basic pharmacological profiles of mAbs that physicians may find useful in establishing their management protocols.

Operator Resource Planning in a Giga Fab during Covid-19 Restrictions

With the world facing a public health emergency due to the Coronavirus disease (COVID-19) in a global pandemic, this paper provides insight about how a simulation model was used to determine the impact of headcount variability during lockdown on fab performance. To create a robust simulation model, operator loading time was introduced as one of the input parameters. An existing and well validated Discrete Event Fab simulation model was extended with operator modelling, and was used to conduct case studies, evaluating the impact of different operator availability scenarios including work disruptions for several shifts within a week. The studies provide implications for operation to derive mitigation strategies, weighing the trade-off between cost demand and speed loss due to operator resources. © 2021 IEEE.

Equine immunoglobulin fragment F(ab')2 displays high neutralizing capability against multiple SARS-CoV-2 variants.

Neutralizing antibody-based passive immunotherapy could be an important therapeutic option against COVID-19. Herein, we demonstrate that equines hyper-immunized with chemically inactivated SARS-CoV-2 elicited high antibody titers with a strong virus-neutralizing potential, and F(ab')2 fragments purified from them displayed strong neutralization potential against five different SARS-CoV-2 variants. F(ab')2 fragments purified from the plasma of hyperimmunized horses showed high antigen-specific affinity. Experiments in rabbits suggested that the F(ab')2 displays a linear pharmacokinetics with approximate plasma half-life of 47 h. In vitro microneutralization assays using the purified F(ab')2 displayed high neutralization titers against five different variants of SARS-CoV-2 including the Delta variant, demonstrating its potential efficacy against the emerging viral variants. In conclusion, this study demonstrates that F(ab')2 generated against SARS-CoV-2 in equines have high neutralization titers and have broad target-range against the evolving variants, making passive immunotherapy a potential regimen against the existing and evolving SARS-CoV-2 variants in combating COVID-19.

In-silico genomic landscape characterization and evolution of SARS-CoV-2 variants isolated in India shows significant drift with high frequency of mutations.

In-silico studies on SARS-CoV-2 genome are considered important to identify the significant pattern of variations and its possible effects on the structural and functional characteristics of the virus. The current study determined such genetic variations and their possible impact among SARS-CoV-2 variants isolated in India. A total of 546 SARS-CoV-2 genomic sequences (India) were retrieved from the gene bank (NCBI) and subjected to alignment against the Wuhan variant (NC_045512.2), the corresponding amino acid changes were analyzed using NCBI Protein-BLAST. These 546 variants revealed 841 mutations; most of these were non-synonymous 464/841 (55.1%), there was no identical variant compared to the original strain. All genes; coding and non-coding showed nucleotide changes, most of the structural genes showed frequent nonsynonymous mutations. The most affected genes were ORF1a/b followed by the S gene which showed 515/841 (61.2%) and 120/841 (14.3%) mutations, respectively. The most frequent non-synonymous mutation 486/546 (89.01%) occurred in the S gene (structural gene) at position 23,403 where A changed to G leading to the replacement of aspartic acid by glycine in position (D614G). Interestingly, four variants also showed deletion. The variants MT800923 and MT800925 showed 12 consecutive nucleotide deletion in position 21982-21993 resulting in 4 consecutive amino acid deletions that were leucine, glycine, valine, and tyrosine in positions 141, 142, 143, and 144 respectively. The present study exhibited a higher mutations rate per variant compared to other studies carried out in India.

RBD-SPECIFIC POLYCLONAL F(ab)2 FRAGMENTS of EQUINE ANTIBODIES in PATIENTS with MODERATE to SEVERE COVID-19 DISEASE

SARS-CoV-2, the causative agent of COVID-19, is currently generating a global pandemic. So far, dexamethasone and remdesivir have shown efficacy in adequately powered clinical trials. In addition, passive immunotherapy appears as a promising therapeutic approach, particularly for early stages of the disease in which patients have not yet established their specific immune response. Different anti-receptor binding domain (RBD) human monoclonal antibodies (mAbs) have been evaluated in the treatment of COVID-19. It has been previously shown that the RBD from the viral spike glycoprotein elicits high titers of NAbs against SARS-CoV-2 when used as immunogen in horses. In this regard, equine polyclonal antibodies (EpAbs) can represent a practical and efficient source of NAbs. EpAbs are composed of F(ab)'2 fragments generated by pepsin digestion. These fragments retain the bivalent binding capacity of IgG immunoglobulins but lack the constant region (Fc), responsible for serum sickness reactions and Fc-triggered side effects. EpAbs recognize a vast array of epitopes (limiting the risk of viral escape mutations) and tend to develop greater avidity than mAbs for their cognate antigens. In addition, EpAbs are relatively easy to manufacture allowing a fast development and scaling up for a treatment. We have previously described the development and in vitro characterization of a therapeutic based on purified equine anti-RBD F(ab)2 fragments, called INM005. INM005 shows a very high serum neutralization titer against SARS-CoV-2. We conducted a phase 2/3 clinical to test the therapeutic effect of INM005 on COVID-19 patients. Albeit not having reached the primary endpoint, we found clinical improvement of hospitalized patients with SARS-CoV-2 pneumonia, particularly those with severe disease. Rate of improvement in at least two categories was statistically significantly higher for INM005 at days 14 and 21 of follow-up. Time to improvement in two ordinal categories or hospital discharge was 14·2 (± 0·7) days in the INM005 group and 16·3 (± 0·7) days in the placebo group. Subgroup analyses showed a beneficial effect of INM005 over severe patients and in those with negative baseline antibodies. Overall mortality was 6·9% the INM005 group and 11·4% in the placebo group. Adverse events of special interest were mild or moderate;no anaphylaxis was reported. Based on these results, ANMAT granted the emergency use approval of INM005 to treat hospitalized COVID-19 severe patients. Following approval, more than 20,000 patients have been treated with INM005. We will be presenting the results of the "real world use of this immunotherapy during the second wave of the pandemics in Argentina.

The Deglycosylated Form of 1E12, a Monoclonal Anti-PF4 IgG, Strongly Inhibits Antibody-Triggered Cellular Activation in Vaccine-Induced Thrombotic Thrombocytopenia, and Is a Potential New Treatment for Vιττ

[Formula presented] Introduction Vaccine-induced thrombotic thrombocytopenia (VITT) is a severe complication of recombinant adenoviral vector vaccines used to prevent COVID-19, likely due to anti-platelet factor 4 (PF4) IgG antibodies. The specificity and platelet-activating activity of VITT antibodies strikingly resemble that of antibodies detected in “autoimmune” heparin-induced thrombocytopenia (HIT), but their features remain poorly characterized. In particular, a better knowledge of these antibodies should help to understand the mechanisms leading to hypercoagulability and the particular thrombotic events observed in VITT, but rarely in typical HIT. We have recently developed a chimeric IgG1 anti-PF4 antibody, 1E12, which strongly mimics “autoimmune” HIT antibodies in terms of specificity and cellular effects. Therefore, we assessed whether 1E12 could mimic VITT antibodies. We then evaluated the capability of DG-1E12, a deglycosylated form of 1E12 unable to bind FcγR, to inhibit cellular activation induced by VITT antibodies. Methods and Results Using a PF4-sensitized serotonin release assay (PF4-SRA) (Vayne C, New Engl J Med, 2021), we demonstrated that 1E12 (5 and 10 μg/mL) strongly activated platelets, with a pattern similar to that obtained with human VITT samples (n=7), i.e. in a PF4-dependent manner and without heparin. This platelet activation was inhibited by low heparin concentration (0.5 IU/mL), an effect also observed with VITT samples. Serotonin release induced by 1E12 was also fully inhibited by IV-3, a monoclonal antibody blocking FcγRIIa, or by IdeS, a bacterial protease that cleaves IgG and strongly inhibits the binding of IgG antibodies to FcγRIIa. This inhibitory effect of IV-3 and IdeS strongly supports that interactions between pathogenic anti-PF4 IgG and FcγRIIa play a central role in VITT. Incubation of 1E12 or VITT samples with isolated neutrophils (PMN) and platelets with PF4 (10 µg/mL) strongly induced DNA release and NETosis, supporting that PMN are involved in the processes leading to thrombosis in VITT. Furthermore, when whole blood from healthy donors incubated with 1E12 or VITT plasma was perfused in capillaries coated with von Willebrand Factor, numerous large platelet/leukocyte aggregates containing fibrin(ogen) were formed. To investigate whether 1E12 and VITT antibodies recognize overlapping epitopes on PF4, we then performed competitive assays with a deglycosylated form of 1E12 (DG-1E12), still able to bind PF4 but not to interact with Fcγ receptors. In PF4-SRA, pre-incubation of DG-1E12 (50 µg/mL) dramatically reduced platelet activation induced by VITT antibodies, which was fully abrogated for 9 of the 14 VITT samples tested. Additional experiments using a whole blood PF4-enhanced flow cytometry assay recently designed for VITT diagnosis (Handtke et al, Blood 2021), confirmed that DG-1E12 fully prevented platelet activation induced by VITT antibodies. Moreover, when platelets and neutrophils were pre-incubated with DG-1E12 (100 µg/mL), NETosis and thus DNA release, nuclear rounding, and DNA decondensation induced by VITT antibodies were completely inhibited. Finally, DG-1E12 (100 µg/mL) also fully abolished VITT antibody-mediated thrombus formation in whole blood in vitro under vein flow conditions. Comparatively, DG-1E12 did not inhibit ALB6, a murine monoclonal anti-CD9 antibody, which also strongly activates platelets in a FcγRIIa-dependent manner. Conclusions Our results show that 1E12 exhibits features similar to those of human VITT antibodies in terms of specificity, affinity and cellular effects, and could therefore be used as a model antibody to study the pathophysiology of VITT. Our data also demonstrate that DG-1E12 prevents blood cell activation and thrombus formation induced by VITT antibodies, likely due to the competitive effect of its Fab fragment on antibody binding to PF4. DG-1E12 may allow the development of a new drug neutralizing the pathogenic effect of autoimmune anti-PF4 antibodies, such as those associated with VITT. Disclosures: T iele: Bristol Myers Squibb: Honoraria, Other;Pfizer: Honoraria, Other;Bayer: Honoraria;Chugai Pharma: Honoraria, Other;Novo Nordisk: Other;Novartis: Honoraria;Daichii Sankyo: Other. Pouplard: Stago: Research Funding. Greinacher: Macopharma: Honoraria;Biomarin/Prosensa: Other, Research Funding;Sagent: Other, Research Funding;Rovi: Other, Research Funding;Gore inc.: Other, Research Funding;Bayer Healthcare: Other, Research Funding;Paringenix: Other, Research Funding;BMS: Honoraria, Other, Research Funding;MSD: Honoraria, Other, Research Funding;Boehringer Ingelheim: Honoraria, Other, Research Funding;Aspen: Honoraria, Other, Research Funding;Portola: Other;Ergomed: Other;Instrument Laboratory: Honoraria;Chromatec: Honoraria. Gruel: Stago: Other: symposium fees, Research Funding. Rollin: Stago: Research Funding.

Production of scFv, Fab, and IgG of CR3022 Antibodies Against SARS-CoV-2 Using Silkworm-Baculovirus Expression System.

COVID-19, caused by SARS-CoV-2, is currently spreading around the world and causing many casualties. Antibodies against such emerging infectious diseases are one of the important tools for basic viral research and the development of diagnostic and therapeutic agents. CR3022 is a monoclonal antibody against the receptor binding domain (RBD) of the spike protein (S protein) of SARS-CoV found in SARS patients, but it was also shown to have strong affinity for that of SARS-CoV-2. In this study, we produced large amounts of three formats of CR3022 antibodies (scFv, Fab and IgG) with high purity using a silkworm-baculovirus expression vector system. Furthermore, SPR measurements showed that the affinity of those silkworm-produced IgG antibodies to S protein was almost the same as that produced in mammalian expression system. These results indicate that the silkworm-baculovirus expression system is an excellent expression system for emerging infectious diseases that require urgent demand for diagnostic agents and therapeutic agents.

History repeats itself: horse originated hyperimmune sera production against SARS CoV-2

Background/aim/AIM: SARS-CoV-2 disease was announced as a pandemic by The World Health Organization in early 2020. It is still threatening the world population. Here, we aimed to produce hyperimmune sera that contain immunoglobulin G and F(ab')2 fragments sourced from horse antibodies as an urgent response to the pandemic. Materials and methods: SARS-CoV-2 was produced and inactivated with three different methods [formaldehyde (FA), formaldehyde, and binary ethylene amine (FA + BEI), and heat treatment]. After in vitro inactivation control, immunogens were mixed with Freund's adjuvant, thereafter horses (n: 2 for FA, 4 for FA + BEI, 2 for heat inactivation) and New Zealand rabbits (n: 6 for FA, 6 fo r FA + BEI, 6 for heat inactivation) were immunized four times. Neutralizing antibody levels of the sera were measured at the 4th, 6th, and 8th weeks. When the antibodies were detected at the peak level, plasma was collected from horses and hyperimmune sera procured after the purification process. Results: Horses and rabbits produced highly neutralizing antibodies against the SARS-CoV-2 in FA and FA + BEI inactivation groups, foreign proteins were removed effectively after purification. Conclusion: This study presents a profitable practice to develop specific antisera in horses against SARS-CoV-2 for emergency and low-cost response. In further studies, new purification methods can be used to increase the efficiency of the final product.

Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies.

Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.

The show must go on! Strategies for making and makerspaces during pandemic.

The COVID-19 pandemic is challenging for Fab Labs and makerspaces where the use of digital fabrication machines and working with physical materials in collaboration with others are at the heart of the activities. We have been actively promoting children's technology education both by training local teachers and by working with children themselves. The restrictions have resulted in limiting the number of participants or moving to online working, or even closing the workspaces and cancelling the events. To continue our work, we needed to explore new solutions for the situation. We have provided online training for teachers, experimented with working in family groups and fully online, while access to the digital fabrication machines and children's engagement in online activities were the largest challenges we encountered. We report in this paper our experiences with different solutions as well as challenges we have faced, both as regards technology education of children and collecting research data related to that.

Structures of Human Antibodies Bound to SARS-CoV-2 Spike Reveal Common Epitopes and Recurrent Features of Antibodies.

Neutralizing antibody responses to coronaviruses mainly target the receptor-binding domain (RBD) of the trimeric spike. Here, we characterized polyclonal immunoglobulin Gs (IgGs) and Fabs from COVID-19 convalescent individuals for recognition of coronavirus spikes. Plasma IgGs differed in their focus on RBD epitopes, recognition of alpha- and beta-coronaviruses, and contributions of avidity to increased binding/neutralization of IgGs over Fabs. Using electron microscopy, we examined specificities of polyclonal plasma Fabs, revealing recognition of both S1A and RBD epitopes on SARS-CoV-2 spike. Moreover, a 3.4 Å cryo-electron microscopy (cryo-EM) structure of a neutralizing monoclonal Fab-spike complex revealed an epitope that blocks ACE2 receptor binding. Modeling based on these structures suggested different potentials for inter-spike crosslinking by IgGs on viruses, and characterized IgGs would not be affected by identified SARS-CoV-2 spike mutations. Overall, our studies structurally define a recurrent anti-SARS-CoV-2 antibody class derived from VH3-53/VH3-66 and similarity to a SARS-CoV VH3-30 antibody, providing criteria for evaluating vaccine-elicited antibodies.

Psychological impact of COVID-19 on healthcare workers: prevalence systematic review

Objective: To synthesize the prevalence of psychological and mental health outcomes among healthcare professionals who are responsible for treating patients with COVID-19. Methods: Systematic literature review. The literature search was carried out in the PubMed, CINAHL and Scopus databases. Studies written in English, Portuguese and Spanish and that were published between December 1st 2019 and July 31st 2020 were included. The systematic review was performed using fixed-effect meta-analysis of binary data with STATA (R) 15.0 and inverse-variance method using Freeman-Tukey double arcsine transformation. Results: The search strategy identified 38,657 records. Only five of those studies were selected and were included in the final review corpus. The meta-analysis conducted showed that the prevalence of depression reached 27.5% (95%CI=25.9-29.3;p<0.001), the prevalence of anxiety was 26.8% (95%CI=25.1-28.5;p<0.001), that of insomnia 35.8% (95%CI=33.8-37.9;p=0.03) and the prevalence of stress amounted to 51.9% (95%CI=49.6-54.3;p<0.001). Three of the studies included in the review show that healthcare professionals have also reported significant levels of vicarious traumatization, posttraumatic stress, somatization, and obsessive-compulsive symptoms. Conclusion: The COVID-19 pandemic is found to have a very significant psychological impact on healthcare workers and is quite likely to lead to an important prevalence of depression, anxiety, insomnia, and stress. Frontline healthcare professionals are a particularly vulnerable group and deserve special attention/ intervention.