scholarly journals Antigenic cartography reveals complexities of genetic determinants that lead to antigenic differences among pandemic GII.4 noroviruses

2021 ◽  
Vol 118 (11) ◽  
pp. e2015874118
Author(s):  
Joseph A. Kendra ◽  
Kentaro Tohma ◽  
Lauren A. Ford-Siltz ◽  
Cara J. Lepore ◽  
Gabriel I. Parra
Keyword(s):  
Herd Immunity ◽  
Structural Protein ◽  
Genetic Determinants ◽  
Antigenic Analysis ◽  
Antigenic Sites ◽  
Virus Like Particle ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Antigenic Cartography

Noroviruses are the predominant cause of acute gastroenteritis, with a single genotype (GII.4) responsible for the majority of infections. This prevalence is characterized by the periodic emergence of new variants that present substitutions at antigenic sites of the major structural protein (VP1), facilitating escape from herd immunity. Notably, the contribution of intravariant mutations to changes in antigenic properties is unknown. We performed a comprehensive antigenic analysis on a virus-like particle panel representing major chronological GII.4 variants to investigate diversification at the inter- and intravariant level. Immunoassays, neutralization data, and cartography analyses showed antigenic similarities between phylogenetically related variants, with major switches to antigenic properties observed over the evolution of GII.4 variants. Genetic analysis indicated that multiple coevolving amino acid changes—primarily at antigenic sites—are associated with the antigenic diversification of GII.4 variants. These data highlight complexities of the genetic determinants and provide a framework for the antigenic characterization of emerging GII.4 noroviruses.

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

scholarly journals TSH Isoforms: About a Case of Hypothyroidism in a Down's Syndrome Young Adult

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Anne-Sophie Gauchez ◽  
Magali Pizzo ◽  
Dany Alcaraz-Galvain ◽  
Karim Chikh ◽  
Jacques Orgiazzi ◽  
...  
Keyword(s):  
Down's Syndrome ◽  
Clinical Manifestations ◽  
Down’S Syndrome ◽  
Thyroid Stimulating Hormone ◽  
Technical Problems ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Negative Effect ◽  
Recent Evaluation

Background. For unknown reasons, the prevalence of thyroid autoimmune disorders is higher in patients with Down's syndrome than in the general population. The present case strongly supports a recent evaluation of propagating screening for thyroid disease in this group of patients to assure early diagnosis of hypothyroidism.Methods. In a 25-year-old man diagnosed with Down's syndrome, clinical manifestations of hypothyroidism were lacking, but profound biochemical abnormalities were found with particularly high levels of thyroid stimulating hormone (TSH). Antigenic properties of TSH were characterized using a panel of anti-TSH antibodies.Results. Technical problems not infrequently associated with TSH measurements are convincingly ruled out. Antigenic characterization of the patient's circulating TSH revealed circulating forms of TSH different from pituitary TSH which closely resembled TSH recombinant human hormone.Conclusions. It appears counterintuitive that the bioactivity of TSH decreases in the hypothyroid state as higher bioactivity of TSH is anticipated in hypothyroidism promoted by an increased hypothalamic TRH drive. In contrast, diminished negative thyroid hormone feedback will enhance posttranslational glycosylation of TSH subunits and increase sialylation of the carbohydrate side chains. Both exert a negative effect on TSH bioactivity, only compensated by the very high levels of the hormone as in the present case.

scholarly journals Distribution of Serogroups ofNeisseria meningitidisand Antigenic Characterization of Serogroup Y Meningococci in Canada, January 1, 1999 to June 30, 2001

2002 ◽  
Vol 13 (6) ◽  
pp. 391-396 ◽  
Author(s):  
Raymond SW Tsang ◽  
Susan G Squires ◽  
Wendell D Zollinger ◽  
Fraser E Ashton
Keyword(s):  
United States ◽  
Meningococcal Disease ◽  
Relative Frequency ◽  
The United States ◽  
Antigenic Analysis ◽  
Laboratory Findings ◽  
Clinical Specimens ◽  
Antigenic Characterization ◽  
Common Serotypes

The relative frequency of serogroups ofNeisseria meningitidisassociated with meningococcal disease in Canada during the period January 1, 1999 to June 30, 2001 was examined. Of the 552 strains ofN meningitidiscollected from clinical specimens of normally sterile sites, 191 (34.6%), 276 (50.0%), 61 (11.1%) and 23 (4.2%) were identified by serological and molecular methods as serogroups B, C, Y and W135, respectively. About half (50.8%) of the serogroup Y isolates were isolated in the province of Ontario. The two most common serotypes found were 2c and 14. Most of the serogroup Y strains isolated from patients in Ontario were serotype 2c, while serotype 14 was the most common serotype associated with disease in the province of Quebec. The two most common serosubtypes found among the serogroup Y meningococci were P1.5 and P1.2,5. Laboratory findings, based on antigenic analysis, did not suggest that these serogroup Y strains arise by capsule switching from serogroups B and C strains. This study documented a higher incidence of finding serogroup Y meningococci in clinical specimens from patients in Ontario compared to the rest of Canada, and parallels the increase in serogroup Y meningococcal disease reported in some parts of the United States.

scholarly journals Characterization of the Sandfly fever Naples species complex and description of a new Karimabad species complex (genus Phlebovirus, family Bunyaviridae)

2014 ◽  
Vol 95 (2) ◽  
pp. 292-300 ◽  
Author(s):  
Gustavo Palacios ◽  
Robert B. Tesh ◽  
Nazir Savji ◽  
Amelia P. A. Travassos da Rosa ◽  
Hilda Guzman ◽  
...  
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Species Complex ◽  
Western Mediterranean ◽  
South American ◽  
Structural Protein ◽  
Toscana Virus ◽  
Antigenic Characterization ◽  
A New Species

Genomic and antigenic characterization of members of the Sandfly fever Naples virus (SFNV) complex reveals the presence of five clades that differ in their geographical distribution. Saint Floris and Gordil viruses, both found in Africa, form one clade; Punique, Granada and Massilia viruses, all isolated in the western Mediterranean, constitute a second; Toscana virus, a third; SFNV isolates from Italy, Cyprus, Egypt and India form a fourth; while Tehran virus and a Serbian isolate Yu 8/76, represent a fifth. Interestingly, this last clade appears not to express the second non-structural protein ORF. Karimabad virus, previously classified as a member of the SFNV complex, and Gabek Forest virus are distinct and form a new species complex (named Karimabad) in the Phlebovirus genus. In contrast with the high reassortment frequency observed in some South American phleboviruses, the only virus of the SFNV complex with evidence of reassortment was Granada virus.

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