Increase in genogroup II.4 norovirus host spectrum by CagA-positive Helicobacter pylori infection.
BACKGROUND
Noroviruses (NoVs) represent a considerable public health burden. Despite their enormous genetic diversity, most outbreaks are due to the single GII.4 genotype, but the reasons for this are poorly understood. NoVs use histo-blood group antigens (HBGAs) as attachment factors. Since HBGAs are present in saliva, binding of strains to saliva is commonly used as a surrogate for recognition of the gut surface by specific strains, although the relationship between saliva and gut tissue expression of HBGAs is not well defined.


METHODS
The presence of fucosylated HBGAs in saliva and stomach biopsy specimens, as well as that of genogroup I.1 and genogroup II.4 virus-like particles, were compared in a series of 109 donors from Portugal.


RESULTS
An overall good concordance between HBGA expression in saliva and stomach surface mucosa was observed. However, unexpected mucosal expression of α(1,2)fucosylated epitopes in nonsecretor individuals was frequently detected, allowing for GII.4 attachment. Although all individuals were infected with Helicobacter pylori, abnormal expression of α(1,2)fucosylated motifs and binding of GII.4 virus-like particles in nonsecretors' mucosa were associated with positivity for the H. pylori CagA virulence factor.


CONCLUSIONS
Infection by CagA-positive H. pylori induces expression of GII.4 attachment factors in nonsecretors' mucosa, expanding the host range of these strains and thereby possibly contributing to their epidemiological dominance.
Inserm, U892; CNRS, UMR 6299; Nantes University, Nantes 44007, France Oniris, Ecole Nationale vétérinaire, Agroalimentaire et de l'alimentation.
Nathalie
N
Ruvoën-Clouet
Institute of Molecular Pathology and Immunology.
Ana
A
Magalhaes
Institute of Molecular Pathology and Immunology Medical Faculty, University of Porto, Portugal.
Lara
L
Marcos-Silva
Inserm, U892; CNRS, UMR 6299; Nantes University, Nantes 44007, France Centre Hospitalier Universitaire de Nantes, Nantes, France.
Adrien
A
Breiman
Institute of Molecular Pathology and Immunology Medical Faculty, University of Porto, Portugal.
Ceu
C
Figueiredo
Institute of Molecular Pathology and Immunology Medical Faculty, University of Porto, Portugal.
Leonor
L
David
Inserm, U892; CNRS, UMR 6299; Nantes University, Nantes 44007, France.
Jacques
J
Le Pendu
D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001789:Blood Group Antigens / Q000032:analysis*; D005753:Gastric Mucosa / Q000737:chemistry* / Q000821:virology*; D005838:Genotype; D064368:Healthy Volunteers; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification; D058507:Host Specificity; D054884:Host-Pathogen Interactions; D006801:Humans; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D011174:Portugal; D011991:Receptors, Virus / Q000032:analysis; D012463:Saliva / Q000737:chemistry* / Q000821:virology*; D037521:Virulence Factors / Q000378:metabolism
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001789:Blood Group Antigens; D011991:Receptors, Virus; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori
CagA; Helicobacter pylori; attachment factor; fucosyltransferases; gastroenteritis; histo-blood group antigens; host-spectrum; norovirus