title: Allergen-driven HLA-G expression and secretion in peripheral blood mononuclear cells from allergic rhinitis patients.
abstract: BACKGROUND
  It has been reported that soluble HLA-G serum levels are increased in patients with pollen-induced allergic rhinitis and decrease after immunotherapy. However, no functional study has been conducted so far. The aim of this study was to evaluate the membrane expression and secretion of HLA-G molecules in peripheral blood mononuclear cells from allergic rhinitis patients after in vitro incubation with the causal allergen.
  
  
  RESULTS
  Twenty-two allergic rhinitis patients and ten healthy subjects were enrolled. Membrane HLA-G expression was determined by flow cytometry and soluble HLA-G in culture supernatant was determined by immunoenzymatic assay. HLA-G expression was detected in CD4+ (T-helper-2) cells and monocytes after in vitro stimulation with the causal allergen but not with non specific stimuli and non causal allergens. Accordingly, the release of soluble HLA-G in culture supernatant occurred only after the stimulation with the causal allergen. Collectively, these results were confirmed by Western blot analysis.
  
  
  CONCLUSIONS
  The present study provides the first in vitro evidence that in allergic patients HLA-G expression and secretion is specifically induced by the causal allergen. These data may add new insights into the pathogenetic mechanisms underlying allergic inflammation and allergen specific immunotherapy.
authors.affiliation: Clinical Immunology, Department of Internal Medicine, University of Genoa & IRCCS-Azienda Ospedaliera Universitaria San Martino, 16132 Genoa, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Contini
authors.affiliation: Clinical Immunology, Department of Internal Medicine, University of Genoa & IRCCS-Azienda Ospedaliera Universitaria San Martino, 16132 Genoa, Italy. Electronic address: puppof@unige.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Puppo
authors.affiliation: Allergy and Respiratory Diseases Units, Department of Internal Medicine, University of Genoa & IRCCS-Azienda Ospedaliera Universitaria San Martino, 16132 Genoa, Italy.
authors.forename: Giorgio Walter
authors.initials: GW
authors.lastname: Canonica
authors.affiliation: Clinical Immunology, Department of Internal Medicine, University of Genoa & IRCCS-Azienda Ospedaliera Universitaria San Martino, 16132 Genoa, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Murdaca
authors.affiliation: Allergy and Respiratory Diseases Units, Department of Internal Medicine, University of Genoa & IRCCS-Azienda Ospedaliera Universitaria San Martino, 16132 Genoa, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ciprandi
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology; D002478:Cells, Cultured; D005006:Ethnicity; D005260:Female; D059951:HLA-G Antigens / Q000235:genetics; D006801:Humans; D007194:India; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D065631:Rhinitis, Allergic / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D000485:Allergens; D059951:HLA-G Antigens
keywords: Allergic rhinitis; CD4 T cells; HLA-G; Monocytes