title: Antigen-specific induction of peripheral T cell tolerance in vivo by codelivery of DNA vectors encoding antigen and Fas ligand.
abstract: Fas ligand (FasL, CD95L) induces apoptosis in activated T cells with upregulated Fas (CD95) expression through the process termed activation-induced cell death (AICD). We postulated that coexpression of antigen and FasL within individual antigen-presenting cells would lead to antigen-specific activation of T cells and to their consequent deletion by FasL-mediated AICD. A DNA-gelatin coacervate containing transferrin cell ligand, calcium, and the lysosomatropic agent chloroquine, a formulation previously shown to achieve high-level transfection of immune and muscle cells in vivo, was used to codeliver plasmids encoding FasL and antigen. Mice developed a strong cytolytic T cell response to beta-Gal when injected with DNA encoding beta-galactosidase (LacZ) model antigen, either as naked DNA or DNA nanoparticles, but failed to respond when there was concomitant injection of nanoparticles containing both the LacZ and murine FasL DNA vectors. This loss of T cell response was systemic, specific for beta-Gal, complete when nanoparticles were administered before antigen challenge, and decreased the T cell response from prior immunization with LacZ DNA. In effect, this "tolerization" injection induced antigen-specific peripheral tolerance in study mice, and represents a possible approach to the treatment of autoimmune diseases and transplantation rejection.
authors.affiliation: Department of Pharmacology and Molecular Science, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Georgantas
authors.forename: K W
authors.initials: KW
authors.lastname: Leong
authors.forename: J T
authors.initials: JT
authors.lastname: August
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D004926:Escherichia coli / Q000235:genetics; D053222:Fas Ligand Protein; D005822:Genetic Vectors / Q000235:genetics* / Q000276:immunology; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D013601:T-Lymphocytes / Q000276:immunology*; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism; D019014:fas Receptor / Q000235:genetics / Q000276:immunology
chemical_list: D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D019014:fas Receptor; D001616:beta-Galactosidase