title: A dendritic cell-based assay for measuring memory T cells specific to dengue envelope proteins in human peripheral blood.
abstract: Dengue envelope (E) protein is a dominant immune inducer and E protein-based vaccines elicited partial to complete protection in non-human primates. To study the immunogenicity of these vaccines in humans, an enzyme linked immunospot (ELISPOT) assay for measuring interferon gamma (IFN-γ) production was developed. Cells from two subject groups, based on dengue-exposure, were selected for assay development. The unique feature of the IFN-γ ELISPOT assay is the utilization of dendritic cells pulsed with E proteins as antigen presenting cells. IFN-γ production, ranging from 53-513 spot forming units per million peripheral blood mononuclear cells (PBMCs), was observed in dengue-exposed subjects as compared to 0-45 IFN-γ spot forming units in dengue-unexposed subjects. Further, both CD4(+) and CD8(+) T cells, and cells bearing CD45RO memory marker, were the major sources of IFN-γ production. The assay allowed quantification of E-specific IFN-γ-secreting memory T cells in subjects 9 years after exposure to a live-attenuated virus vaccine and live-virus challenge. Results suggested that the dendritic cell-based IFN-γ assay is a useful tool for assessing immunological memory for clinical research.
authors.affiliation: Henry Jackson Foundation for the Military Service, Rockville, MD, USA. Peifang.sun@med.navy.mil
authors.forename: Peifang
authors.initials: P
authors.lastname: Sun
authors.forename: Charmagne
authors.initials: C
authors.lastname: Beckett
authors.forename: Janine
authors.initials: J
authors.lastname: Danko
authors.forename: Timothy
authors.initials: T
authors.lastname: Burgess
authors.forename: Zhaodong
authors.initials: Z
authors.lastname: Liang
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Kochel
authors.forename: Kevin
authors.initials: K
authors.lastname: Porter
mesh_terms: D001769:Blood / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology; D002478:Cells, Cultured; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003713:Dendritic Cells / Q000276:immunology*; D053059:Dengue Vaccines / Q000276:immunology*; D058501:Enzyme-Linked Immunospot Assay / Q000379:methods; D006801:Humans; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology*
chemical_list: D053059:Dengue Vaccines; D014759:Viral Envelope Proteins; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens