11,056 results match your criteria serum neutralization


Engineering of single-domain antibodies for next generation snakebite antivenoms.

Int J Biol Macromol 2021 Jun 9. Epub 2021 Jun 9.

Plataforma Bi-Institucional de Medicina Translacional (Fiocruz-USP), Ribeirão Preto, São Paulo, Brazil.

Given the magnitude of the global snakebite crisis, strategies to ensure the quality of antivenom, as well as the availability and sustainability of its supply are under development by several research groups. Recombinant DNA technology has allowed the engineering of monoclonal antibodies and recombinant fragments as alternatives to conventional antivenoms. Besides higher therapeutic efficacy, with broad neutralization capacity against local and systemic toxicity, novel antivenoms have to ensure safety and cost-effectivity. Read More

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Validation of high-throughput, semiquantitative solid phase SARS coronavirus-2 serology assays in serum and dried blood spot matrices.

Bioanalysis 2021 Jun 11. Epub 2021 Jun 11.

Synexa Life Sciences, 4 Kunene Circle, Montague Gardens, Cape Town, 7441, South Africa.

Serological assays for the detection of anti-SARS coronavirus-2 (SARS-CoV-2) antibodies are essential to the response to the global pandemic. A ligand binding-based serological assay was validated for the semiquantitative detection of IgG, IgM, IgA and neutralizing antibodies (nAb) against SARS-CoV-2 in serum. The assay demonstrated high levels of diagnostic specificity and sensitivity (85-99% for all analytes). Read More

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Heterologous immunization with Covishield and Pfizer vaccines against SARS-CoV-2 elicits a robust humoral immune response.

J Infect Dev Ctries 2021 05 31;15(5):653-656. Epub 2021 May 31.

Department of Microbiology and Immunology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.

Understanding the efficacy and durability of heterologous immunization schedules against SARS-CoV-2 is critical, as supply demands and vaccine choices become significant issues in the global vaccination strategy. Here we characterize the neutralizing antibodies produced in two subjects who received combination immunizations against SARS-CoV-2, first with Covishield (Oxford-AstraZeneca) vaccine, followed 33 days later with a second dose (booster) shot of the Pfizer-BioNTech vaccine. Serum samples were collected 25 days following the primary vaccination and 13 days after the secondary Pfizer vaccination. Read More

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TNF blockade uncouples toxicity from antitumor efficacy induced with CD40 chemoimmunotherapy.

JCI Insight 2021 Jun 8. Epub 2021 Jun 8.

Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, United States of America.

Agonist CD40 antibodies are under clinical development in combination with chemotherapy as an approach to prime for anti-tumor T cell immunity. However, treatment with anti-CD40 is commonly accompanied by both systemic cytokine release and liver transaminase elevations which together account for the most common dose-limiting toxicities. Moreover, anti-CD40 treatment increases the potential for chemotherapy-induced hepatotoxicity. Read More

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Impaired Humoral Immunity to SARS-CoV-2 Vaccination in Non-Hodgkin Lymphoma and CLL Patients.

medRxiv 2021 Jun 3. Epub 2021 Jun 3.

Patients with hematologic malignancies are a high priority for SARS-CoV-2 vaccination, yet the benefit they will derive is uncertain. We investigated the humoral response to vaccination in 53 non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), or CLL patients. Peripheral blood was obtained 2 weeks after first vaccination and 6 weeks after second vaccination for antibody profiling using the multiplex bead-binding assay. Read More

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SARS-CoV-2 elicits robust adaptive immune responses regardless of disease severity.

EBioMedicine 2021 Jun 4;68:103410. Epub 2021 Jun 4.

Department of Infectious Diseases, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.

Background: The SARS-CoV-2 pandemic currently prevails worldwide. To understand the immunological signature of SARS-CoV-2 infections and aid the search and evaluation of new treatment modalities and vaccines, comprehensive characterization of adaptive immune responses towards SARS-CoV-2 is needed.

Methods: We included 203 recovered SARS-CoV-2 infected patients in Denmark between April 3 and July 9 2020, at least 14 days after COVID-19 symptom recovery. Read More

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Anti-Psoriatic Effects of Middle Fragment of Chlamydial Plasmid-Encoded Protein pGP3 in an Imiquimod-Induced Psoriasis Mouse Model.

Med Sci Monit 2021 Jun 5;27:e929781. Epub 2021 Jun 5.

Department of Dermatology and Venereology, Tianjin Medical University General Hospital, Tianjin, China (mainland).

BACKGROUND Previously, we demonstrated that the chlamydial protein pGP3 forms a stable complex with LL-37 to neutralize its proinflammatory activity during the pathogenesis of psoriasis. The middle domain of pGP3 (pGP3M) is critical for the binding and neutralization of LL-37. Here, we further examined the mechanism underlying pGP3-mediated inhibition of psoriasis progression and evaluated the inhibitory effect of pGP3M on the development of psoriasis-like skin lesions in mice. Read More

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A Narrative Review of a Pulmonary Aerosolized Formulation or a Nasal Drop Using Sera Containing Neutralizing Antibodies Collected from COVID-19-Recovered Patients as a Probable Therapy for COVID-19.

Iran J Med Sci 2021 May;46(3):151-168

School of Pharmacy, Al-Hawash Private University, Homs, Syria.

Coronavirus disease 2019 (COVID-19) emerged as a new contagion during December 2019, since which time it has triggered a rampant spike in fatality rates worldwide due to insufficient medical treatments and a lack of counteragents and prompted the World Health Organization to declare COVID-19 a public health emergency. It is, therefore, vital to accelerate the screening of new molecules or vaccines to win the battle against this pandemic. Experiences from previous epidemiological data on coronaviruses guide investigators in designing and exploring new compounds for a safe and cost-effective treatment. Read More

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IMMUNO-COV v2.0: Development and Validation of a High-Throughput Clinical Assay for Measuring SARS-CoV-2-Neutralizing Antibody Titers.

mSphere 2021 Jun 2:e0017021. Epub 2021 Jun 2.

Imanis Life Sciences, Rochester, Minnesota, USA.

Neutralizing antibodies are key determinants of protection from future infection, yet well-validated high-throughput assays for measuring titers of SARS-CoV-2-neutralizing antibodies are not generally available. Here, we describe the development and validation of IMMUNO-COV v2.0, a scalable surrogate virus assay, which titrates antibodies that block infection of Vero-ACE2 cells by a luciferase-encoding vesicular stomatitis virus displaying SARS-CoV-2 spike glycoproteins (VSV-SARS2-Fluc). Read More

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Evidence of neutralizing antibodies against SARS-CoV-2 in domestic cats living with owners with a history of COVID-19 in Lima - Peru.

bioRxiv 2021 May 26. Epub 2021 May 26.

SARS-CoV-2 can infect a variety of wild and domestic animals worldwide. Of these, domestic cats are highly susceptible species and potential viral reservoirs. As such, it is important to investigate disease exposure in areas with active community transmission and high disease prevalence. Read More

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SARS-CoV-2 variants, spike mutations and immune escape.

Nat Rev Microbiol 2021 Jun 1. Epub 2021 Jun 1.

MRC-University of Glasgow Centre for Virus Research, Glasgow, UK.

Although most mutations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome are expected to be either deleterious and swiftly purged or relatively neutral, a small proportion will affect functional properties and may alter infectivity, disease severity or interactions with host immunity. The emergence of SARS-CoV-2 in late 2019 was followed by a period of relative evolutionary stasis lasting about 11 months. Since late 2020, however, SARS-CoV-2 evolution has been characterized by the emergence of sets of mutations, in the context of 'variants of concern', that impact virus characteristics, including transmissibility and antigenicity, probably in response to the changing immune profile of the human population. Read More

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A Virus-Like Particle-Based Vaccine Candidate against the Tick-Borne Powassan Virus Induces Neutralizing Antibodies in a Mouse Model.

Pathogens 2021 May 31;10(6). Epub 2021 May 31.

American Type Culture Collection (ATCC®), ATCC Federal Solutions, 10801 University Boulevard, Manassas, VA 20110, USA.

Powassan virus (POWV) is a tick-borne flavivirus circulating in North America and the Russian Far East that can cause severe neuroinvasive diseases, including encephalitis, meningitis, and meningoencephalitis. The reported neuroinvasive case fatality is about 10%, and approximately 50% of the survivors from the neuroinfection exhibit long-lasting or permanent neurological sequelae. Currently, treatment of POWV infection is supportive, and no FDA-approved vaccines or specific therapeutics are available. Read More

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Prevalence of Linda Virus Neutralizing Antibodies in the Austrian Pig Population.

Viruses 2021 May 27;13(6). Epub 2021 May 27.

Department for Pathobiology, Institute of Virology, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.

A novel pestivirus species, termed Lateral-shaking Inducing Neuro-Degenerative Agent virus (LindaV), was discovered in a piglet-producing farm in Austria in 2015 related to severe congenital tremor cases. Since the initial outbreak LindaV has not been found anywhere else. In this study, we determined the seroprevalence of LindaV infections in the domestic pig population of Austria. Read More

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Evaluation of a Pseudovirus Neutralization Assay for SARS-CoV-2 and Correlation with Live Virus-Based Micro Neutralization Assay.

Diagnostics (Basel) 2021 May 30;11(6). Epub 2021 May 30.

Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 128442, Jeddah 21362, Saudi Arabia.

The unusual cases of pneumonia outbreak were reported from Wuhan city in late December 2019. Serological testing provides a powerful tool for the identification of prior infection and for epidemiological studies. Pseudotype virus neutralization assays are widely used for many viruses and applications in the fields of serology. Read More

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Utility of Different Surrogate Enzyme-Linked Immunosorbent Assays (sELISAs) for Detection of SARS-CoV-2 Neutralizing Antibodies.

J Clin Med 2021 May 14;10(10). Epub 2021 May 14.

Institute for Medical Virology, University Hospital, Goethe University Frankfurt am Main, 60596 Frankfurt, Germany.

The plaque reduction neutralization test (PRNT) is a preferred method for the detection of functional, SARS-CoV-2 specific neutralizing antibodies from serum samples. Alternatively, surrogate enzyme-linked immunosorbent assays (ELISAs) using ACE2 as the target structure for the detection of neutralization-competent antibodies have been developed. They are capable of high throughput, have a short turnaround time, and can be performed under standard laboratory safety conditions. Read More

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Human Milk from Previously COVID-19-Infected Mothers: The Effect of Pasteurization on Specific Antibodies and Neutralization Capacity.

Nutrients 2021 May 13;13(5). Epub 2021 May 13.

Department of Pediatrics, Amsterdam UMC, Vrije Universiteit, University of Amsterdam Emma Children's Hospital, 1105 AZ Amsterdam, The Netherlands.

Background: Since the outbreak of coronavirus disease 2019 (COVID-19), many put their hopes in the rapid availability of effective immunizations. Human milk, containing antibodies against syndrome coronavirus 2 (SARS-CoV-2), may serve as means of protection through passive immunization. We aimed to determine the presence and pseudovirus neutralization capacity of SARS-CoV-2 specific IgA in human milk of mothers who recovered from COVID-19, and the effect of pasteurization on these antibodies. Read More

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Scalable, Micro-Neutralization Assay for Assessment of SARS-CoV-2 (COVID-19) Virus-Neutralizing Antibodies in Human Clinical Samples.

Viruses 2021 05 12;13(5). Epub 2021 May 12.

Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702, USA.

As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic expanded, it was clear that effective testing for the presence of neutralizing antibodies in the blood of convalescent patients would be critical for development of plasma-based therapeutic approaches. To address the need for a high-quality neutralization assay against SARS-CoV-2, a previously established fluorescence reduction neutralization assay (FRNA) against Middle East respiratory syndrome coronavirus (MERS-CoV) was modified and optimized. The SARS-CoV-2 FRNA provides a quantitative assessment of a large number of infected cells through use of a high-content imaging system. Read More

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Human Immunodeficiency Viruses Pseudotyped with SARS-CoV-2 Spike Proteins Infect a Broad Spectrum of Human Cell Lines through Multiple Entry Mechanisms.

Viruses 2021 05 21;13(6). Epub 2021 May 21.

Public Health Research Institute, Rutgers, the State University of New Jersey, Newark, NJ 07103, USA.

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), enters cells through attachment to the human angiotensin converting enzyme 2 (hACE2) via the receptor-binding domain (RBD) in the surface/spike (S) protein. Several pseudotyped viruses expressing SARS-CoV-2 S proteins are available, but many of these can only infect hACE2-overexpressing cell lines. Here, we report the use of a simple, two-plasmid, pseudotyped virus system comprising a SARS-CoV-2 spike-expressing plasmid and an HIV vector with or without to investigate the SARS-CoV-2 entry event in various cell lines. Read More

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Low Seroprevalence of Aichi Virus Infection in Taiwan.

Pathogens 2021 May 3;10(5). Epub 2021 May 3.

Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei 11490, Taiwan.

Aichi virus (AiV) belongs to the genus of the family Picornaviridae; it is a single-stranded positive-sense RNA virus without an envelope. AiV causes acute gastroenteritis, abdominal pain, nausea, vomiting, and fever. Low incidence and high seroprevalence of AiV infections have been reported in several regions of the world; however, little was known on the prevalence of AiV infections in Taiwan. Read More

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Long-Term Protection and Serologic Response of European Sea Bass Vaccinated with a Betanodavirus Virus-Like Particle Produced in .

Vaccines (Basel) 2021 May 2;9(5). Epub 2021 May 2.

National Institute of Aquatic Resources (DTU AQUA), Technical University of Denmark, 2800 Lyngby, Denmark.

Viral Nervous Necrosis (VNN) causes high mortality and reduced growth in farmed European sea bass () in the Mediterranean. In the current studies, we tested a novel -produced virus-like particle (VLP) vaccine against VNN in European sea bass, caused by the betanodavirus "Red-Spotted Grouper Nervous Necrosis Virus" (RGNNV). European sea bass were immunized with a VLP-based vaccine formulated with different concentrations of antigen and with or without adjuvant. Read More

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Iron biodistribution profile changes in the rat spleen after administration of high-fat diet or iron supplementation and the role of curcumin.

J Mol Histol 2021 May 28. Epub 2021 May 28.

Department of Histology, Faculty of Medicine, Sohag University, Sohag, 82524, Egypt.

Curcumin as active metal chelating and antioxidant agent has a potential role in metal reduction and free radicals' neutralization in tissues. Of note, long-term administration of high fat diet (HFD) is considered as a main factor of blood serum iron deficiency. This study aimed to investigate the biodistribution profiles of iron in the spleen after long-term administration of HFD along with iron supplementation. Read More

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Immune response to SARS-CoV-2 variants of concern in vaccinated individuals.

Nat Commun 2021 05 25;12(1):3109. Epub 2021 May 25.

NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany.

SARS-CoV-2 is evolving with mutations in the receptor binding domain (RBD) being of particular concern. It is important to know how much cross-protection is offered between strains following vaccination or infection. Here, we obtain serum and saliva samples from groups of vaccinated (Pfizer BNT-162b2), infected and uninfected individuals and characterize the antibody response to RBD mutant strains. Read More

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SARS-CoV-2 mRNA vaccines induce a greater array of spike-specific antibody isotypes with more potent complement binding capacity than natural infection.

medRxiv 2021 May 17. Epub 2021 May 17.

Background: Mass vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is on-going in the United States with vaccines approved for emergency use by the FDA. Each vaccine can induce spike-specific antibodies (Abs) with virus-neutralizing activities; however, the Fc-mediated Ab activities have received little attention. Moreover, while plasma/serum Abs are commonly studied, scant information is available about Abs in the respiratory mucosa, the site of SARS-CoV-2 transmission. Read More

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Alum:CpG adjuvant enables SARS-CoV-2 RBD-induced protection in aged mice and synergistic activation of human elder type 1 immunity.

bioRxiv 2021 May 21. Epub 2021 May 21.

Global deployment of vaccines that can provide protection across several age groups is still urgently needed to end the COVID-19 pandemic especially for low- and middle-income countries. While vaccines against SARS-CoV-2 based on mRNA and adenoviral-vector technologies have been rapidly developed, additional practical and scalable SARS-CoV-2 vaccines are needed to meet global demand. In this context, protein subunit vaccines formulated with appropriate adjuvants represent a promising approach to address this urgent need. Read More

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Genetic Characterization of Feline Parvovirus Isolate Fe-P2 in Korean Cat and Serological Evidence on Its Infection in Wild Leopard Cat and Asian Badger.

Front Vet Sci 2021 7;8:650866. Epub 2021 May 7.

Department of Microbiology, College of Natural Science, Chungbuk National University, Cheongju, South Korea.

Feline parvovirus (FPV) is a small, non-enveloped, single-stranded DNA virus that infects cats. We recently isolated a feline parvovirus Fe-P2 strain from a dead stray cat in Iksan, 2017. Its partial genomic sequence (4,643 bases) was obtained, and phylogenetic analysis based on the VP2 nucleotide sequence showed that the FPV Fe-P2 strain was closely related to the FPV isolate Gigucheon in cat, 2017 (MN400978). Read More

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Influence of adjuvants on the amount, specificity and functional activity of antibody response to human influenza vaccine in mice.

Mol Immunol 2021 Jul 20;135:398-407. Epub 2021 May 20.

Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Av. Universidad 3000, CP 04510, Ciudad de México, Mexico. Electronic address:

It's been almost a century since immunologists started using adjuvants as tools to develop more effective vaccines. Despite the rising number of adjuvanted vaccines in the last decades, we still lack knowledge of the adjuvants' effects on antibody response. This study was aimed to test the effect of immunizing mice with the human Inactivated Influenza vaccine (IIV), either alone or combined with different widely used adjuvants on the specific antibody response induced. Read More

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CXCL1 Recruits NK Cells Into the Central Nervous System and Aggravates Brain Injury of Mice Caused by Infection.

Front Cell Infect Microbiol 2021 4;11:672720. Epub 2021 May 4.

Department of Pathogen Biology, Key Laboratory of Pathogen Biology of Jiangsu Province, Nanjing Medical University, Nanjing, China.

Background: (), is a food-borne zoonotic parasite that can cause central nervous system (CNS) injury characterized by eosinophilic meningitis. However, the pathogenesis of angiostrongylosis remains elusive. Natural killer cells (NK cells) are unique innate lymphocytes important in early defense against pathogens. Read More

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Infection and vaccine-induced neutralizing antibody responses to the SARS-CoV-2 B.1.617.1 variant.

bioRxiv 2021 May 10. Epub 2021 May 10.

SARS-CoV-2 has caused a devastating global pandemic. The recent emergence of SARS-CoV-2 variants that are less sensitive to neutralization by convalescent sera or vaccine-induced neutralizing antibody responses has raised concerns. A second wave of SARS-CoV-2 infections in India is leading to the expansion of SARS-CoV-2 variants. Read More

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Translational PK/PD and model-informed development of JNJ-67842125, a F reversal agent for JNJ-64179375, a long-acting thrombin inhibitor.

Br J Pharmacol 2021 May 18. Epub 2021 May 18.

Clinical Pharmacology and Pharmacometrics, Janssen Research & Development, LLC, United States.

Background And Purpose: Antigen-binding fragment (F ) reversal agents (RAs) were developed to reverse, in situations of bleeding emergency, the anticoagulant activity of JNJ-64179375 (JNJ-9375), a monoclonal antibody that specifically binds exosite-1 on thrombin and functions as a long-acting anticoagulant.

Experimental Approach: The pharmacokinetic and pharmacodynamic (PK/PD) activities of three RAs with varying in vitro binding affinities to JNJ-9375 were characterized in cynomolgus monkeys. The time course of JNJ-9375 anticoagulant activity and reversal effects of each RA were evaluated. Read More

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Dynamics of neutralizing antibody responses to SARS-CoV-2 in patients with COVID-19: an observational study.

Signal Transduct Target Ther 2021 05 18;6(1):197. Epub 2021 May 18.

State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Guangdong Provincial Clinical Research Center for Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China.

Our understanding of the protective immunity, particularly the long-term dynamics of neutralizing antibody (NAbs) response to SARS-CoV-2, is currently limited. We enrolled a cohort of 545 COVID-19 patients from Hubei, China, who were followed up up to 7 months, and determined the dynamics of NAbs to SARS-CoV-2 by using a surrogate virus neutralization test (sVNT). In our validation study, sVNT IC titers and the neutralization rate measured at a single dilution (1:20) were well correlated with FRNT titers (r = 0. Read More

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