scholarly journals Kinetics of Neutralizing Antibodies of COVID-19 Patients Tested Using Clinical D614G, B.1.1.7 and B 1.351 Isolates in Microneutralization Assays

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 996
Author(s):  
Jenni Virtanen ◽  
Ruut Uusitalo ◽  
Essi M. Korhonen ◽  
Kirsi Aaltonen ◽  
Teemu Smura ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Acute Infection ◽  
Clinical Isolates ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Kinetics Of

Increasing evidence suggests that some newly emerged SARS-CoV-2 variants of concern (VoCs) resist neutralization by antibodies elicited by the early-pandemic wild-type virus. We applied neutralization tests to paired recoveree sera (n = 38) using clinical isolates representing the first wave (D614G), VoC1, and VoC2 lineages (B.1.1.7 and B 1.351). Neutralizing antibodies inhibited contemporary and VoC1 lineages, whereas inhibition of VoC2 was reduced 8-fold, with 50% of sera failing to show neutralization. These results provide evidence for the increased potential of VoC2 to reinfect previously SARS-CoV-infected individuals. The kinetics of NAbs in different patients showed similar decline against all variants, with generally low initial anti-B.1.351 responses becoming undetectable, but with anti-B.1.1.7 NAbs remaining detectable (>20) for months after acute infection.

scholarly journals Antibody Escape Kinetics of Equine Infectious Anemia Virus Infection of Horses

2015 ◽  
Vol 89 (13) ◽  
pp. 6945-6951 ◽  
Author(s):  
Elissa J. Schwartz ◽  
Seema Nanda ◽  
Robert H. Mealey
Keyword(s):  
Neutralizing Antibodies ◽  
Equine Infectious Anemia Virus ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Fitness Costs ◽  
Equine Infectious Anemia ◽  
Anemia Virus ◽  
Kinetics Of ◽  
Virus Fitness

Lentivirus escape from neutralizing antibodies (NAbs) is not well understood. In this work, we quantified antibody escape of a lentivirus, using antibody escape data from horses infected with equine infectious anemia virus. We calculated antibody blocking rates of wild-type virus, fitness costs of mutant virus, and growth rates of both viruses. These quantitative kinetic estimates of antibody escape are important for understanding lentiviral control by antibody neutralization and in developing NAb-eliciting vaccine strategies.

scholarly journals Structural Basis for Accommodation of Emerging B.1.351 and B.1.1.7 Variants by Two Potent SARS-CoV-2 Neutralizing Antibodies

2021 ◽  
Author(s):  
Gabriele Cerutti ◽  
Micah Rapp ◽  
Yicheng Guo ◽  
Fabiana Bahna ◽  
Jude Bimela ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Wild Type Virus ◽  
Receptor Binding Domain ◽  
Type Virus ◽  
Wild Type ◽  
Distinct Mechanism ◽  
The Uk

SummaryEmerging SARS-CoV-2 strains, B.1.1.7 and B.1.351, from the UK and South Africa, respectively show decreased neutralization by monoclonal antibodies and convalescent or vaccinee sera raised against the original wild-type virus, and are thus of clinical concern. However, the neutralization potency of two antibodies, 1-57 and 2-7, which target the receptor-binding domain (RBD) of spike, was unaffected by these emerging strains. Here, we report cryo-EM structures of 1-57 and 2-7 in complex with spike, revealing each of these antibodies to utilize a distinct mechanism to bypass or accommodate RBD mutations. Notably, each antibody represented a response with recognition distinct from those of frequent antibody classes. Moreover, many epitope residues recognized by 1-57 and 2-7 were outside hotspots of evolutionary pressure for both ACE2 binding and neutralizing antibody escape. We suggest the therapeutic use of antibodies like 1-57 and 2-7, which target less prevalent epitopes, could ameliorate issues of monoclonal antibody escape.

scholarly journals Vaccination with SARS-CoV-2 variants of concern protects mice from challenge with wild-type virus

PLoS Biology ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. e3001384
Author(s):  
Fatima Amanat ◽  
Shirin Strohmeier ◽  
Philip Meade ◽  
Nicholas Dambrauskas ◽  
Barbara Mühlemann ◽  
...  
Keyword(s):  
Mouse Model ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Fold Reduction ◽  
Reactive Antibody

Vaccines against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been highly efficient in protecting against Coronavirus Disease 2019 (COVID-19). However, the emergence of viral variants that are more transmissible and, in some cases, escape from neutralizing antibody responses has raised concerns. Here, we evaluated recombinant protein spike antigens derived from wild-type SARS-CoV-2 and from variants B.1.1.7, B.1.351, and P.1 for their immunogenicity and protective effect in vivo against challenge with wild-type SARS-CoV-2 in the mouse model. All proteins induced high neutralizing antibodies against the respective viruses but also induced high cross-neutralizing antibody responses. The decline in neutralizing titers between variants was moderate, with B.1.1.7-vaccinated animals having a maximum fold reduction of 4.8 against B.1.351 virus. P.1 induced the most cross-reactive antibody responses but was also the least immunogenic in terms of homologous neutralization titers. However, all antigens protected from challenge with wild-type SARS-CoV-2 in a mouse model.

scholarly journals Persistence of neutralizing antibodies a year after SARS-CoV-2 infection

2021 ◽  
Author(s):  
Anu Haveri ◽  
Nina Ekström ◽  
Anna Solastie ◽  
Camilla Virta ◽  
Pamela Österlund ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Severe Infection ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Serum Antibodies ◽  
Respiratory Coronavirus ◽  
Insight Into

Understanding for how long antibodies persist following Severe acute respiratory coronavirus 2 (SARS-CoV-2) infection provides important insight into estimating the duration of immunity induced by infection. We assessed the persistence of serum antibodies following wild-type SARS-CoV-2 infection six and twelve months after diagnosis in 367 individuals of whom 13% had severe disease requiring hospitalization. We determined the SARS-CoV-2 spike (S-IgG) and nucleoprotein IgG concentrations and the proportion of subjects with neutralizing antibodies (NAb). We also measured the NAb titers among a smaller subset of participants (n=78) against a wild-type virus (B.1) and three variants of concern (VOCs): Alpha (B.1.1.7), Beta (B.1.351) and Delta (B.1.617.2). We found that NAb against the wild-type virus and S-IgG persisted in 89% and 97% of subjects for at least twelve months after infection, respectively. IgG and NAb levels were higher after severe infection. NAb titers were significantly lower against variants compared to the wild-type virus.

scholarly journals Vaccine-Induced T Cells Control Reversion of AIDS Virus Immune Escape Mutants

2007 ◽  
Vol 81 (8) ◽  
pp. 4137-4144 ◽  
Author(s):  
Caroline S. Fernandez ◽  
Miranda Z. Smith ◽  
C. Jane Batten ◽  
Robert De Rose ◽  
Jeanette C. Reece ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Acute Infection ◽  
T Cell Response ◽  
Mutant Virus ◽  
Wild Type Virus ◽  
Escape Mutant ◽  
Type Virus ◽  
Wild Type ◽  
Hiv Vaccines

ABSTRACT Many current-generation human immunodeficiency virus (HIV) vaccines induce specific T cells to control acute viremia, but their utility following infection with escape mutant virus is unclear. We studied reversion to wild type of an escape mutant simian-HIV in major histocompatibility complex-matched vaccinated pigtail macaques. High levels of vaccine-induced CD8+ T cells strongly correlated with maintenance of escape mutant virus during acute infection. Interestingly, in animals with lower CD8+ T-cell levels, transient reversion to wild-type virus resulted in better postacute control of viremia. Killing of wild-type virus facilitated by transient reversion outweighs the benefit of a larger CD8+ T-cell response that only maintains the less fit escape mutant virus. These findings have important implications for the further development of T-cell-based HIV vaccines where exposure to escape mutant viruses is common.

scholarly journals Difference of hemaglutinins between wild-type and vaccine measles virus in Indonesia

2008 ◽  
Vol 48 (1) ◽  
pp. 42
Author(s):  
Made Setiawan ◽  
Agus Sjahrurachman ◽  
Fera Ibrahim ◽  
Agus Suwandono
Keyword(s):  
Neutralizing Antibodies ◽  
Measles Virus ◽  
Vaccine Virus ◽  
Amino Acid Sequences ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Cell Infection ◽  
Aminoacid Sequence ◽  
H Protein

Background Hemaglutinin (H) protein of measles virus is veryimportant in the process of host cell infection. H protein is alsoable to induce specific antibodies which can neutralize measlesvirus and block the cell infection.Objective This study aimed to explore the nucleotide and aminoacid sequence differences between wild-type measles virus (G2,G3 and D9) with CAM-70, Schwarz and Edmonston-wt vaccinevirus.Methods The exctration and amplification of the gene wereconducted in the laboratory using biomolecular technology. Thegene and protein analysis were conducted using the bioinformatictechnology.Results The results showed that the differences in nucleotidesequences were highest between wild-type virus and CAM-70vaccine virus (76-77 nucleotides), followed by Schwarz (61-64nucleotides) and Edmonston (60-63 nucleotides). The differencesin amino acid sequences were highest between wild-type virusand CAM-70 (24-29 residues), followed by Schwarz (13-20residues) and Edmonston (12-19 residues).Conclusion The Indonesian wild-type measles virus was geneticallycloser to Schwarz vaccine virus than CAM-70 vaccine virus,hence the neutralizing antibodies generated by Schwarz vaccinewere more specific against Indonesian wild-type virus comparedto CAM-70 vaccine.

scholarly journals Murine Gammaherpesvirus 68 Cyclin D Homologue Is Required for Efficient Reactivation from Latency

2000 ◽  
Vol 74 (15) ◽  
pp. 7016-7023 ◽  
Author(s):  
Ann T. Hoge ◽  
Sara B. Hendrickson ◽  
William H. Burns
Keyword(s):  
Acute Infection ◽  
Human Herpesvirus ◽  
Wild Type Virus ◽  
Cyclin D ◽  
Type Virus ◽  
Wild Type ◽  
Virus Growth ◽  
Murine Gammaherpesvirus ◽  
Gammaherpesvirus 68 ◽  
Murine Gammaherpesvirus 68

ABSTRACT Murine gammaherpesvirus 68 (MHV68) is a gammaherpesvirus that was first isolated from murid rodents. MHV68 establishes a latent infection in the spleen and other lymphoid organs. Several gammaherpesviruses, including herpesvirus saimiri, human herpesvirus 8, and MHV68, encode proteins with extensive homology to the D-type cyclins. To study the function of the cyclin homologue, a recombinant MHV68 has been constructed that lacks the cyclin homologue and expresses β-galactosidase as a marker (MHV68cy−). MHV68cy− grows in vitro with kinetics and to titers similar to those of the wild type. BALB/c mice infected with mixtures of equivalent amounts of the wild type and MHV68cy− show deficient growth of the MHV68cy− in an acute infection. Infection of SCID mice with virus mixtures also showed decreased MHV68cy−virus growth, indicating that the deficiency is not mediated by T or B cells. Although mice infected with mixtures containing 100 times as much MHV68cy− had greater splenic titers of the mutant virus than wild-type virus in acute infection, at 28 days postinfection splenocytes from these mice reactivated primarily wild-type virus. Quantitative PCR data indicate that equivalent genomes were present in the latent state. Reinsertion of the cyclin homologue into the cyclin-deleted virus restored the wild-type phenotype. These results indicate that the MHV68 cyclin D homologue mediates important functions in the acute infection and is required for efficient reactivation from latency.

scholarly journals Serum Neutralizing Activity of mRNA-1273 Against SARS-CoV-2 Variants

2021 ◽  
Author(s):  
Angela Choi ◽  
Matthew Koch ◽  
Kai Wu ◽  
Groves Dixon ◽  
Judy Oestreicher ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Neutralizing Activity ◽  
Serum Neutralization ◽  
Vaccination Strategies ◽  
Fold Reduction ◽  
Alpha Variant ◽  
Multiple Variants

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has led to growing concerns over increased transmissibility and the ability of some variants to partially escape immunity. Sera from participants immunized on a prime-boost schedule with the mRNA-1273 COVID-19 vaccine were tested for neutralizing activity against several SARS-CoV-2 variants, including variants of concern (VOCs) and variants of interest (VOIs), compared to neutralization of the wild-type SARS-CoV-2 virus (designated as D614G). Results showed minimal, statistically non-significant effects on neutralization titers against the B.1.1.7 (Alpha) variant (1.2-fold reduction compared with D614G); other VOCs such as B.1.351 (Beta, including B.1.351-v1, B.1.351-v2, and B.1.351-v3), P.1 (Gamma), and B.1.617.2 (Delta), showed significantly decreased neutralization titers ranging from 2.1-fold to 8.4-fold reductions compared with D614G, although all remained susceptible to mRNA-1273–elicited serum neutralization. IMPORTANCE In light of multiple variants of SARS-CoV-2 that have been documented globally during the COVID-19 pandemic, it remains important to continually assess the ability of currently available vaccines to confer protection against newly emerging variants. Data presented herein indicate that immunization with the mRNA-1273 COVID-19 vaccine produces neutralizing antibodies against key emerging variants tested, including variants of concern and variants of interest. While the serum neutralization elicited by mRNA-1273 against most variants tested was reduced compared with the wild-type virus, they are still expected to be protective. Such data are crucial to inform ongoing and future vaccination strategies to combat COVID-19.

scholarly journals Avian polyomavirus mutants with deletions in the VP4-encoding region show deficiencies in capsid assembly and virus release, and have reduced infectivity in chicken

2007 ◽  
Vol 88 (3) ◽  
pp. 823-830 ◽  
Author(s):  
Reimar Johne ◽  
Guntram Paul ◽  
Dirk Enderlein ◽  
Tobias Stahl ◽  
Christian Grund ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Biological Properties ◽  
Wild Type Virus ◽  
Deletion Mutants ◽  
Virus Release ◽  
Type Virus ◽  
Wild Type ◽  
Embryo Cells ◽  
Infected Cells ◽  
Avian Polyomavirus

Avian polyomavirus (APV) is the causative agent of an acute fatal disease in psittacine and some non-psittacine birds. In contrast to mammalian polyomaviruses, the APV genome encodes the additional capsid protein VP4 and its variant VP4Δ, truncated by an internal deletion. Both proteins induce apoptosis. Mutation of their common initiation codon prevents virus replication. Here, the generation of replication competent deletion mutants expressing either VP4 or VP4Δ is reported. In contrast to infection with wild-type virus, chicken embryo cells showed no cytopathic changes after infection with the mutants, and induction of apoptosis as well as virus release from the infected cells were delayed. Electron microscopy revealed the presence of a high proportion of small particles and tubules in preparations of the VP4 deletion mutant, indicating a scaffolding function for VP4. Wild-type and mutant viruses elicited neutralizing antibodies against APV after intramuscular and intraperitoneal infection of chicken; however, VP4-specific antibodies were only detected after infection with wild-type virus. Using the oculonasal route of infection, seroconversion was only observed in chickens infected with the wild-type virus, indicating a strongly reduced infectivity of the mutants. Based on the biological properties of the deletion mutants, they could be considered as candidates for APV marker vaccines.

scholarly journals Growth Kinetics of Influenza C Virus Antigenic Mutants that Escaped from Anti-Hemagglutinin Esterase Monoclonal Antibodies and Viral Antigenic Changes Found in Field Isolates

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 401
Author(s):  
Yoko Matsuzaki ◽  
Kanetsu Sugawara ◽  
Yoshitaka Shimotai ◽  
Yoko Kadowaki ◽  
Seiji Hongo ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Growth Kinetics ◽  
Antigenic Site ◽  
Antigenic Drift ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Viral Propagation ◽  
Influenza C Virus ◽  
Kinetics Of

The antigenicity of the hemagglutinin esterase (HE) glycoprotein of influenza C virus is known to be stable; however, information about residues related to antigenic changes has not yet been fully acquired. Using selection with anti-HE monoclonal antibodies, we previously obtained some escape mutants and identified four antigenic sites, namely, A-1, A-2, A-3, and Y-1. To confirm whether the residues identified as the neutralizing epitope possibly relate to the antigenic drift, we analyzed the growth kinetics of these mutants. The results showed that some viruses with mutations in antigenic site A-1 were able to replicate to titers comparable to that of the wild-type, while others showed reduced titers. The mutants possessing substitutions in the A-2 or A-3 site replicated as efficiently as the wild-type virus. Although the mutant containing a deletion at positions 192 to 195 in the Y-1 site showed lower titers than the wild-type virus, it was confirmed that this region in the 190-loop on the top side of the HE protein is not essential for viral propagation. Then, we revealed that antigenic changes due to substitutions in the A-1, A-3, and/or Y-1 site had occurred in nature in Japan for the past 30 years. These results suggest that some residues (i.e., 125, 176, 192) in the A-1 site, residue 198 in the A-3 site, and residue 190 in the Y-1 site are likely to mediate antigenic drift while maintaining replicative ability.

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