scholarly journals New detection of SARS-CoV-2 in two cats height months after COVID-19 outbreak appearance in France

2021 ◽  
Author(s):  
Matthieu Fritz ◽  
Nicolas Nesi ◽  
Solene Denolly ◽  
Bertrand Boson ◽  
Vincent Legros ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Molecular Biology ◽  
Neutralizing Antibodies ◽  
Clinical Observation ◽  
Infection Status ◽  
Serological Analysis ◽  
S Protein ◽  
N Protein ◽  
Additional Information ◽  
Microsphere Immunoassay

Although there are several reports in the literature of SARS-CoV-2 infection in cats, few SARS-CoV-2 sequences from infected cats have been published. In this report, SARS-CoV-2 infection was evaluated in two cats by clinical observation, molecular biology (qPCR and NGS), and serology (Microsphere immunoassay and seroneutralization). Following the observation of symptomatic SARS-CoV-2-infection in two cats, infection status was confirmed by RT-qPCR and, in one cat, serological analysis for antibodies against N-protein and S-protein, as well as neutralizing antibodies. Comparative analysis of five SARS-CoV-2 sequence-fragments obtained from one of the cats showed that this infection was not with one of the three recently emerged variants of SARS-CoV-2. This study provides additional information on the clinical, molecular, and serological aspects of SARS-CoV-2 infection in cats.

scholarly journals Circulating anti-SARS-CoV-2 nucleocapsid (N)-protein antibodies and anti-SARS-CoV-2 spike (S)-protein antibodies in an African setting: herd immunity, not there yet!

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Mveang Nzoghe ◽  
Marielle Leboueny ◽  
Eliane Kuissi Kamgaing ◽  
Anicet Christel Maloupazoa Siawaya ◽  
Eliode Cyrien Bongho ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Total Population ◽  
Herd Immunity ◽  
Humoral Response ◽  
S Protein ◽  
N Protein ◽  
African Context ◽  
African Setting

Abstract Objective Herd immunity is achieved when in a population, immune individuals are in a sufficiently large proportion. Neutralizing antibodies specific to SARS-CoV-2 that are produced following infection or vaccination are critical for controlling the spread of COVID-19. The objective of the present work was to investigate the rate of SARS-CoV-2 natural immunization in Gabonese. Results One thousand, four hundred and ninety two people were enrolled. The overall prevalence of anti-SARS-CoV-2 antibodies was 36.2%. Moreover, 76.4% of people who developed a humoral response to SARS-CoV-2 produced both anti-SARS-CoV-2 N-protein antibodies and anti-SARS-CoV-2 S-protein antibodies, which correspond to 27.7% of the total population. In infants (0–9 month), children (1–17 years) and adults, the prevalence of anti-SARS-CoV-2 antibodies was relatively the same, between 33 and 37% (any antibody types) and between 25 and 28.6% (neutralizing antibodies). In this African context, one-third (1/3) of the screened population was exposed to SARS-CoV-2 and three-quarter (3/4) of those exposed individuals developed neutralizing antibodies against SARS-CoV-2. This data suggest that herd immunity is not yet to be achieved in Gabon.

scholarly journals Evaluation of Antibody Response Directed against Porcine Reproductive and Respiratory Syndrome Virus Structural Proteins

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 533
Author(s):  
Hung Q. Luong ◽  
Huong T. L. Lai ◽  
Hiep L. X. Vu
Keyword(s):  
Comparative Analysis ◽  
Liquid Phase ◽  
Antibody Response ◽  
Antibody Responses ◽  
Structural Proteins ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
N Protein ◽  
Additional Information ◽  
Kinetics Of

Luciferase-immunoprecipitation system (LIPS), a liquid phase immunoassay, was used to evaluate antibody responses directed against the structural proteins of PRRSV in pigs that were experimentally infected with virulent PRRSV strains. First, the viral N protein was used as a model antigen to validate the assay. The LIPS results were highly comparable to that of the commercial IDEXX PRRS X3 ELISA. Subsequently, the assay was applied to simultaneously measure antibody reactivity against all eight structural proteins of PRRSV. The highest immunoreactivities were detected against GP3, M, and N proteins while the lowest reactivity was detected against ORF5a protein. Comparative analysis of the kinetics of antibody appearance revealed that antibodies specific to N protein appeared earlier than antibodies against GP3. Finally, the assay was applied to measure immunoreactivities of clinical serum samples against N and GP3. The diagnostic sensitivity of the LIPS with N protein was superior to that of the LIPS with GP3. Collectively, the results provide additional information about the host antibody response to PRRSV infection.

scholarly journals Severity, Pathogenicity and Transmissibility of Delta and Lambda Variants of SARS-CoV-2, Toxicity of Spike Protein and Possibilities for Future Prevention of COVID-19

2021 ◽  
Vol 9 (10) ◽  
pp. 2167
Author(s):  
Mehrnoosh Moghaddar ◽  
Ramtin Radman ◽  
Ian Macreadie
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
World Health ◽  
The Novel ◽  
S Protein ◽  
N Protein ◽  
Novel Variants ◽  
Hotspot Mutations ◽  
Health Organization

The World Health Organization reports that SARS-CoV-2 has infected over 220 million people and claimed over 4.7 million lives globally. While there are new effective vaccines, the differences in behavior of variants are causing challenges in vaccine development or treatment. Here, we discuss Delta, a variant of concern, and Lambda, a variant of interest. They demonstrate high infectivity and are less responsive to the immune response in vaccinated individuals. In this review, we briefly summarize the reason for infectivity and the severity of the novel variants. Delta and Lambda variants exhibit more changes in NSPs proteins and the S protein, compared to the original Wuhan strain. Lambda also has numerous amino acid substitutions in NSPs and S proteins, plus a deletion in the NTD of S protein, leading to partial escape from neutralizing antibodies (NAbs) in vaccinated individuals. We discuss the role of furin protease and the ACE2 receptor in virus infection, hotspot mutations in the S protein, the toxicity of the S protein and the increased pathogenicity of Delta and Lambda variants. We discuss future therapeutic strategies, including those based on high stability of epitopes, conservation of the N protein and the novel intracellular antibody receptor, tripartite-motif protein 21 (TRIM21) recognized by antibodies against the N protein.

scholarly journals 418. Comparison of the Abbott SARS-CoV-2 IgG and DiaSorin LIASON SARS-CoV-2 S1/S2 IgG Antibody Assays

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S276-S277
Author(s):  
Grace A Schaack ◽  
Derrick Chen
Keyword(s):  
Disease Surveillance ◽  
Neutralizing Antibodies ◽  
Infection Prevalence ◽  
Reference Laboratory ◽  
Igg Antibody ◽  
S Protein ◽  
N Protein ◽  
Negative Results ◽  
Antibody Assays ◽  
Lab Test

Abstract Background The Abbott Laboratories SARS-CoV-2 IgG assay and the DiaSorin LIASON SARS-CoV-2 S1/S2 IgG assay are both chemiluminescent immunoassays that qualitatively detect IgG antibodies against SARS-CoV-2 antigens. The Abbott assay detects IgG against the viral nucleocapsid (N) protein, while the DiaSorin assay uses antigen derived from the viral spike (S) protein. Here we evaluate the performance of these two assays at our institution. Methods 45 patient samples (serum or plasma) were tested for anti-SARS-CoV-2 IgG by both the Abbott and DiaSorin assays. The samples were previously characterized at a national reference laboratory using the Abbott assay or by an in-house PCR-based test for SARS-CoV-2 RNA. Samples yielding discordant results across platforms were further tested using the EUROIMMUN Anti-SARS-CoV-2 ELISA (IgG) assay at the reference laboratory. Results 22 samples tested negative for SARS-CoV-2 by the reference lab Abbott assay, and 23 tested positive by the same reference lab test (n = 13) or by an in-house PCR-based test (n = 10). The 22 samples characterized as negative again tested negative by both the Abbott (in-house) and DiaSorin assays (100% NPA). Among the 23 samples characterized as positive, all 23 tested positive by the Abbott assay (100% PPA), while only 15 tested positive by the DiaSorin assay (65% PPA). For each of the 8 discordant cases, samples were further tested by EUROIMMUN assay, which targets the S protein; 7 of the 8 samples tested negative by this assay, in agreement with the DiaSorin test results. Thus, for the discordant cases, testing for IgG against N (in-house and reference lab Abbott assays) gave positive results, while testing for IgG against S (DiaSorin and EUROIMMUN assays) mostly gave negative results. Conclusion These findings highlight the importance of the differences between various SARS-CoV-2 antibody tests, and providers should be aware of the specific antigenic target(s) in each test. Selection of a specific assay may depend on the need to assess past exposure to SARS-CoV-2 (for which a nucleocapsid target may be more sensitive) or to detect neutralizing antibodies (for which a spike target may be more relevant). This also has implications for disease surveillance as reliance on anti-spike antibodies alone may underestimate infection prevalence. Disclosures All Authors: No reported disclosures

scholarly journals Amino Acids 1055 to 1192 in the S2 Region of Severe Acute Respiratory Syndrome Coronavirus S Protein Induce Neutralizing Antibodies: Implications for the Development of Vaccines and Antiviral Agents

2005 ◽  
Vol 79 (6) ◽  
pp. 3289-3296 ◽  
Author(s):  
Choong-Tat Keng ◽  
Aihua Zhang ◽  
Shuo Shen ◽  
Kuo-Ming Lip ◽  
Burtram C. Fielding ◽  
...  
Keyword(s):  
Amino Acids ◽  
Severe Acute Respiratory Syndrome ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Antiviral Agents ◽  
Host Cells ◽  
Heptad Repeat ◽  
Antigenic Determinants ◽  
Amino Acid Residues ◽  
S Protein

ABSTRACT The spike (S) protein of the severe acute respiratory syndrome coronavirus (SARS-CoV) interacts with cellular receptors to mediate membrane fusion, allowing viral entry into host cells; hence it is recognized as the primary target of neutralizing antibodies, and therefore knowledge of antigenic determinants that can elicit neutralizing antibodies could be beneficial for the development of a protective vaccine. Here, we expressed five different fragments of S, covering the entire ectodomain (amino acids 48 to 1192), as glutathione S-transferase fusion proteins in Escherichia coli and used the purified proteins to raise antibodies in rabbits. By Western blot analysis and immunoprecipitation experiments, we showed that all the antibodies are specific and highly sensitive to both the native and denatured forms of the full-length S protein expressed in virus-infected cells and transfected cells, respectively. Indirect immunofluorescence performed on fixed but unpermeabilized cells showed that these antibodies can recognize the mature form of S on the cell surface. All the antibodies were also able to detect the maturation of the 200-kDa form of S to the 210-kDa form by pulse-chase experiments. When the antibodies were tested for their ability to inhibit SARS-CoV propagation in Vero E6 culture, it was found that the anti-SΔ10 antibody, which was targeted to amino acid residues 1029 to 1192 of S, which include heptad repeat 2, has strong neutralizing activities, suggesting that this region of S carries neutralizing epitopes and is very important for virus entry into cells.

scholarly journals A single immunization with a rhabdovirus-based vector expressing severe acute respiratory syndrome coronavirus (SARS-CoV) S protein results in the production of high levels of SARS-CoV-neutralizing antibodies

2005 ◽  
Vol 86 (5) ◽  
pp. 1435-1440 ◽  
Author(s):  
Milosz Faber ◽  
Elaine W. Lamirande ◽  
Anjeanette Roberts ◽  
Amy B. Rice ◽  
Hilary Koprowski ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Protein S ◽  
S Protein ◽  
Cellular Immune Responses ◽  
Glycoprotein G ◽  
Cellular Immune ◽  
Animal Reservoirs ◽  
S Genes

Foreign viral proteins expressed by rabies virus (RV) have been shown to induce potent humoral and cellular immune responses in immunized animals. In addition, highly attenuated and, therefore, very safe RV-based vectors have been constructed. Here, an RV-based vaccine vehicle was utilized as a novel vaccine against severe acute respiratory syndrome coronavirus (SARS-CoV). For this approach, the SARS-CoV nucleocapsid protein (N) or envelope spike protein (S) genes were cloned between the RV glycoprotein G and polymerase L genes. Recombinant vectors expressing SARS-CoV N or S protein were recovered and their immunogenicity was studied in mice. A single inoculation with the RV-based vaccine expressing SARS-CoV S protein induced a strong SARS-CoV-neutralizing antibody response. The ability of the RV-SARS-CoV S vector to confer immunity after a single inoculation makes this live vaccine a promising candidate for eradication of SARS-CoV in animal reservoirs, thereby reducing the risk of transmitting the infection to humans.

scholarly journals Nucleocapsid vaccine elicits spike-independent SARS-CoV-2 protective immunity

2021 ◽  
Author(s):  
William E. Matchett ◽  
Vineet Joag ◽  
J. Michael Stolley ◽  
Frances K. Shepherd ◽  
Clare F. Quarnstrom ◽  
...  
Keyword(s):  
Weight Loss ◽  
Viral Load ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Protein A ◽  
Receptor Binding Domain ◽  
Immune Effector ◽  
N Protein ◽  
Viral Antigens ◽  
Successful Vaccine

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Neutralizing antibodies target the receptor binding domain of the spike (S) protein, a focus of successful vaccine efforts. Concerns have arisen that S-specific vaccine immunity may fail to neutralize emerging variants. We show that vaccination with HAd5 expressing the nucleocapsid (N) protein can establish protective immunity, defined by reduced weight loss and viral load, in both Syrian hamsters and k18-hACE2 mice. Challenge of vaccinated mice was associated with rapid N-specific T cell recall responses in the respiratory mucosa. This study supports the rationale for including additional viral antigens, even if they are not a target of neutralizing antibodies, to broaden epitope coverage and immune effector mechanisms.

scholarly journals COMPARATIVE ANALYSIS OF THE LEVEL OF STUDENTS` ACADEMIC MOTIVATION TO SOFIA UNIVERSITY „ST. KLIMENT OHRIDSKI” AND NATIONAL ACADEMIA OF SPORT „VASIL LEVSKI”

2019 ◽  
Vol 34 (2) ◽  
pp. 571-578
Author(s):  
Georgi Ignatov ◽  
Iliana Petkova
Keyword(s):  
Comparative Analysis ◽  
Physical Education ◽  
Young People ◽  
Learning Process ◽  
Academic Motivation ◽  
Present Report ◽  
Theoretical Background ◽  
Active Involvement ◽  
Additional Information ◽  
Key Factor

The present report addresses a topic that is a key factor for the quality of the education in universities. The outcome this education depends on the degree of students’ academic motivation and results in their readiness for certain profession. The material presents the results from a study conducted in the period 2016-2019 among 45 students in their second and third year of studies in the subject „Physical Education and Sport“ at the Sofia University „St. Kliment Ohridski“ Faculty of Science, Education and Arts and 39 students also studying „Physical Education“ but at the National Sports Academy „Vasil Levski“ Faculty of Pedagogy. As a research tool, was used a questionnaire designed for determining the academic motivation, developed by Angel Velichkov. The questionnaire contained 11 questions, of which 7 with positive and 4 with negative direction. The assessment was done through the 4-point Likert scale, where 0 is „completely disagree” and 3 is „completely agree”. In his work A. Velichkov places the degree of academic motivation within the following limits: 0-11 points – lack of academic motivation; 12-18 points – weak motivation; 19-24 points – moderate motivation, 25-33 points – strong academic motivation. The summaries are made both on universities and on each individual indicator for academic motivation, including: „Active attitude to the learning process“, „Internal self-discipline“ and „Strive to complement and broaden the obtained knowledge“. To determine the priorities of young people, we divided their statements that received the highest percentage of opinions „agree“ on the positively formulated questions and „disagree“ on the negative ones. The comparative analysis shows that the overall degree of academic motivation is not high among students from both Universities. However, students in both universities are convinced that active involvement in the learning process is required. Students are aware of the importance of the theoretical background they need to acquire during their studies. They are motivated to gain lasting knowledge and excellence in all subjects studied. Young people indicate that they complement and broaden their knowledge by seeking additional information and by consultations with university professors.

scholarly journals SARS-CoV-2 mRNA vaccines induce a robust germinal centre reaction in humans

2021 ◽  
Author(s):  
Ali Ellebedy ◽  
Jackson Turner ◽  
Jane O'Halloran ◽  
Elizaveta Kalaidina ◽  
Wooseob Kim ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Messenger Rna ◽  
Neutralizing Antibodies ◽  
Germinal Centre ◽  
S Protein ◽  
Fine Needle Aspirates ◽  
Cell Responses ◽  
Cell Clones ◽  
Shared Epitopes

Abstract Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA)-based vaccines are ~95% effective in preventing coronavirus disease 2019. However, the dynamics of antibody secreting plasmablasts (PBs) and germinal centre (GC) B cells induced by these vaccines in SARS-CoV-2 naïve and antigen-experienced humans remains unclear. Here we examined peripheral blood and/or lymph node (LN) antigen-specific B cell responses in 32 individuals who received two doses of BNT162b2, an mRNA-based vaccine encoding the full-length SARS-CoV-2 spike (S) gene. Circulating IgG- and IgA-secreting PBs targeting the S protein peaked one week after the second immunization then declined and were undetectable three weeks later. PB responses coincided with maximal levels of serum anti-S binding and neutralizing antibodies to a historical strain as well as emerging variants, especially in individuals previously infected with SARS-CoV-2, who produced the most robust serological responses. Fine needle aspirates of draining axillary LNs identified GC B cells that bind S protein in all participants sampled after primary immunization. GC responses increased after boosting and were detectable in two distinct LNs in several participants. Remarkably, high frequencies of S-binding GC B cells and PBs were maintained in draining LNs for up to seven weeks after first immunization, with a substantial fraction of the PB pool class-switched to IgA. GC B cell-derived monoclonal antibodies predominantly targeted the RBD, with fewer clones binding to the N-terminal domain or shared epitopes within the S proteins of human betacoronaviruses OC43 and HKU1. Our studies demonstrate that SARS-CoV-2 mRNA-based vaccination of humans induces a robust and persistent GC B cell response that engages pre-existing as well as new B cell clones, which enables generation of high-affinity, broad, and durable humoral immunity.

The Cellular and Molecular Biology of HIV-1 Broadly Neutralizing Antibodies

2015 ◽  
pp. 441-461
Author(s):  
Barton F. Haynes ◽  
Kevin O. Saunders ◽  
Garnett Kelsoe ◽  
John R. Mascola ◽  
Gary J. Nabel
Keyword(s):  
Molecular Biology ◽  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
Hiv 1
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