title: Detection of low-frequency human antigen-specific CD4(+) T cells using MHC class II multimer bead sorting and immunoscope analysis.
abstract: MHC class II tetramers are attractive tools to study antigen-specific CD4(+) T cell responses in various clinical situations in humans. HLA-DRA1*0101/DRB1*0401 MHC class II heterodimers were produced as empty molecules using the Drosophila melanogaster expression system. Peptide binding experiments revealed that these molecules could be loaded efficiently with appropriate MHC class II tumor epitopes. Interestingly, MHC class II tetramer staining was influenced by modifications in membrane lipid rafts, and could in itself induce activation changes of stained CD4(+) T cells at 37 degrees C. In order to increase the threshold of detection of poorly represented peripheral antigen-specific CD4(+) T cells, we combined cell sorting using MHC class II multimer beads together with TCR analysis using the immunoscope technology. This strategy greatly increased the sensitivity of detection of specific CD4(+) T cells to frequencies as low as 4 x 10(-6) among peripheral blood mononuclear cells. Such a combined approach may have promising applications in the immunomonitoring of patients under vaccination protocols to tightly follow induced antigen-specific CD4(+) T cells expressing previously identified TCR.
authors.affiliation: Unité de Recherche et d'Expertise Immunité anti-virale, Biothérapie et Vaccins, INSERM U277, Institut Pasteur, Paris, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Lemaître
authors.forename: Manuelle
authors.initials: M
authors.lastname: Viguier
authors.forename: Min-Sun
authors.initials: MS
authors.lastname: Cho
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Fourneau
authors.forename: Bernard
authors.initials: B
authors.lastname: Maillère
authors.forename: Philippe
authors.initials: P
authors.lastname: Kourilsky
authors.forename: Peter M
authors.initials: PM
authors.lastname: Van Endert
authors.forename: Laurent
authors.initials: L
authors.lastname: Ferradini
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004331:Drosophila melanogaster; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005822:Genetic Vectors; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007158:Immunologic Techniques
chemical_list: D000951:Antigens, Neoplasm; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II