title: Human immune response to cationized proteins. II. Characterization of interaction of cationized diphtheria toxoid with human mononuclear cells.
abstract: Cationized diphtheria toxoid (cDT) has previously been shown to be more effective than the native protein as an inducer of human antigen-specific T cell responses. In the present study, biotin-labeled antigen and flow cytometric analysis were used to examine the possibility that enhanced immunogenicity of cDT may be a consequence of preferential binding to antigen-presenting cells. Strong binding of cDT, relative to native antigen, was noted for both monocytes and B cells. Characteristics of binding were similar for both cell types, including rapid saturation, temperature independence, and inhibition by unlabeled cationized proteins. Although both B cells and monocytes bound cDT, only monocytes were effective in triggering T cell proliferation, possibly as a result of slow internalization of bound antigen by B cells. Definition of the target structures of cationized proteins may allow for the design of more efficient vaccines, which would be specifically targeted to antigen-presenting cells in vivo.
authors.affiliation: Abbott Laboratories Diagnostics Division, New Markers R&D, Abbott Park, Illinois 60064.
authors.forename: J L
authors.initials: JL
authors.lastname: Farmer
authors.forename: L A
authors.initials: LA
authors.lastname: Roberts
authors.forename: M E
authors.initials: ME
authors.lastname: Rydzinski
authors.forename: M D
authors.initials: MD
authors.lastname: Hilty
mesh_terms: D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D001665:Binding Sites; D002412:Cations; D004167:Diphtheria Toxin / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D015195:Drug Design; D006801:Humans; D009000:Monocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D014612:Vaccines / Q000737:chemistry
chemical_list: D002412:Cations; D004167:Diphtheria Toxin; D014612:Vaccines