scholarly journals Characterization of Antigenic Relatedness Among GI Norovirus Genotypes Using Serum Samples From Norovirus-Infected Patients and Mouse Sera

2020 ◽  
Vol 11 ◽  
Author(s):  
Dongjie Xie ◽  
Junrui Chen ◽  
Jingrong Yu ◽  
Fuyu Pei ◽  
Mark Momoh Koroma ◽  
...  
Keyword(s):  
Immune Response ◽  
Binding Affinity ◽  
Phylogenetic Relationship ◽  
Biological Properties ◽  
Virus Spread ◽  
Gastroenteritis Outbreak ◽  
Serum Samples ◽  
Antigenic Relatedness ◽  
Primary Focus

Characterizing diversity and the antigenic relatedness of norovirus remains a primary focus in understanding its biological properties and vaccine designs. The precise antigenic and serological features of GI genotypes have not been studied. The study represented an investigation on a gastroenteritis outbreak related to GI.3 norovirus and the three most detected GI genotypes, GI.2 (belonging to immunotype B), GI.3 and GI.9 (belonging to immunotype C), were selected to characterize their phylogenetic relationship, HBGA binding profiles and antigenic relatedness within (intra-immunotype), and between (inter-immunotypes) genotypes using mouse sera and patient’s serum samples from the GI.3 related outbreak. Wide HBGA binding profiles and evolution of binding affinity were observed in the three GI genotypes studied. A low specific blockade antibody to GI.3 in the population generated the pool of susceptible individuals and supported virus spread in the outbreak. We found strong blockade immune response in homologous strains, moderate intra-immunotype blockade but weak inter-immunotypes blockade in humans following GI.3 norovirus infections. These findings further support the immunotypes grouping and will be valuable for optimizing the design of norovirus vaccine.

Immunological and genetic characterization of Borrelia burgdorferi BapA and EppA proteins

Microbiology ◽  
2003 ◽  
Vol 149 (5) ◽  
pp. 1113-1125 ◽  
Author(s):  
Jennifer C. Miller ◽  
Brian Stevenson
Keyword(s):  
Immune Response ◽  
Borrelia Burgdorferi ◽  
Selective Pressure ◽  
Genetic Characterization ◽  
Sequence Analyses ◽  
Serum Samples ◽  
Strong Immune Response ◽  
Considerable Evidence ◽  
Infectious Cycle

A large majority of examined Lyme disease spirochaete isolates were demonstrated to contain one or both of the paralogous genes bapA and eppA. Immunological analyses of serum samples collected from infected patients coupled with comparative sequence analyses indicated that bapA gene sequences are quite stable but the encoded proteins do not provoke a strong immune response in most individuals. Conversely, EppA proteins are much more antigenic but vary widely in sequence between different bacteria. Considerable evidence of insertion, deletion and other mutations within eppA genes was observed. A number of significant recombination events were also found to have occurred in regions flanking bapA genes, while the genes themselves rarely exhibited evidence of mutation, suggesting strong selective pressure to maintain BapA sequences within narrow limits. Data from these and other studies suggest important roles for BapA and EppA during the Borrelia burgdorferi infectious cycle.

scholarly journals Characterization of Antigenic Relatedness between GII.4 and GII.17 Noroviruses by Use of Serum Samples from Norovirus-Infected Patients

2017 ◽  
Vol 55 (12) ◽  
pp. 3366-3373 ◽  
Author(s):  
Ying-Chun Dai ◽  
Ming Xia ◽  
Qiong Huang ◽  
Ming Tan ◽  
Lin Qin ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immune Reactivity ◽  
Serum Samples ◽  
Antigenic Relatedness ◽  
New Variant ◽  
Antigenic Type ◽  
Blocking Assay ◽  
Selection Of

ABSTRACTA novel GII.17 norovirus variant caused major gastroenteritis epidemics in China in 2014 to 2016. To explore the host immune factors in selection of the emergence of this new variant, we characterized its antigenic relatedness with the GII.4 noroviruses that have dominated in China for decades. Through an enzyme-linked immunosorbent assay (ELISA) and a histo-blood group antigen (HBGA) blocking assay using sera from GII.4 and the GII.17 variant-infected patients, respectively, we observed limited cross-immune reactivity by the ELISA but little reactivity by the HBGA blocking assay between GII.4 norovirus and the new GII.17 variant. Our data suggest that, among other possible factors, GII.4-specific herd immunity had little role in the emergence of the new GII.17 variant. Thus, GII.17 may be an important active antigenic type or immunotype that needs to be considered for future vaccine strategies against human noroviruses.

Characterization of Portuguese Propolis: Unraveling Biological Properties

Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
CA Aguiar ◽  
AM Ferreira ◽  
R Oliveira ◽  
F Baltazar ◽  
A Cunha
Keyword(s):  
Biological Properties

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

scholarly journals Vaccination strategy and anti - SARS-CoV-2 S titers in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Geometric Mean ◽  
Vaccination Strategy ◽  
Antibody Responses ◽  
Cancer Center ◽  
Serum Samples ◽  
Humoral Immune ◽  
History Of

Abstract Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. Methods We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Results Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ($$ \overline{x} $$ x ¯ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. Conclusions The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

scholarly journals Physicochemical Characterization Cascade of Nanoadjuvant–Antigen Systems for Improving Vaccines

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 544
Author(s):  
Giuditta Guerrini ◽  
Antonio Vivi ◽  
Sabrina Gioria ◽  
Jessica Ponti ◽  
Davide Magrì ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Structure ◽  
Physicochemical Properties ◽  
Physicochemical Characterization ◽  
Protein Antigen ◽  
Efficacy And Safety

Adjuvants have been used for decades to enhance the immune response to vaccines, in particular for the subunit-based adjuvants. Physicochemical properties of the adjuvant-protein antigen complexes, such as size, morphology, protein structure and binding, influence the overall efficacy and safety of the vaccine. Here we show how to perform an accurate physicochemical characterization of the nanoaluminum–ovalbumin complex. Using a combination of existing techniques, we developed a multi-staged characterization strategy based on measurements of increased complexity. This characterization cascade has the advantage of being very flexible and easily adaptable to any adjuvant-protein antigen combinations. It will contribute to control the quality of antigen–adjuvant complexes and immunological outcomes, ultimately leading to improved vaccines.

scholarly journals Population (Antibody) Testing for COVID-19—Technical Challenges, Application and Relevance, an English Perspective

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 550
Author(s):  
Peter A. C. Maple
Keyword(s):  
National Level ◽  
Herd Immunity ◽  
Population Based ◽  
Biological Properties ◽  
Limited Extent ◽  
Antibody Testing ◽  
Serum Samples ◽  
Oral Fluids ◽  
Antibody Assays ◽  
The Uk

In the UK, population virus or antibody testing using virus swabs, serum samples, blood spots or oral fluids has been performed to a limited extent for several diseases including measles, mumps, rubella and hepatitis and HIV. The collection of population-based infection and immunity data is key to the monitoring of disease prevalence and assessing the effectiveness of interventions such as behavioural modifications and vaccination. In particular, the biological properties of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its interaction with the human host have presented several challenges towards the development of population-based immunity testing. Measuring SARS-CoV-2 immunity requires the development of antibody assays of acceptable sensitivity and specificity which are capable of accurately detecting seroprevalence and differentiating protection from non-protective responses. Now that anti-COVID-19 vaccines are becoming available there is a pressing need to measure vaccine efficacy and the development of herd immunity. The unprecedented impact of the SARS-CoV-2 pandemic in the UK in terms of morbidity, mortality, and economic and social disruption has mobilized a national scientific effort to learn more about this virus. In this article, the challenges of testing for SARS-CoV-2 infection, particularly in relation to population-based immunity testing, will be considered and examples given of relevant national level studies.

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