title: Modulation of gene expression related to Toll-like receptor signaling in dendritic cells by poly(gamma-glutamic acid) nanoparticles.
abstract: Poly(gamma-glutamic acid) (gamma-PGA) nanoparticles (NPs) have previously been reported as an efficient antigen delivery system with adjuvant activity. In this study, the gene expression in murine bone marrow-derived dendritic cells (DCs) treated with gamma-PGA NPs was examined by oligonucleotide microarray analysis and compared with that in cells treated with other adjuvants. The gene expression of proinflammatory chemokines, cytokines, and costimulatory molecules was upregulated considerably in DCs treated with gamma-PGA NPs. The upregulation pattern was similar to that in DCs treated with lipopolysaccharide (LPS) but not to that in DCs treated with unparticulate gamma-PGA. The activation of DCs by gamma-PGA NPs was confirmed by real-time reverse transcriptase PCR (RT-PCR) analysis of genes related to Toll-like receptor (TLR) signaling. The effect of gamma-PGA NPs on DCs was not annihilated by treatment with polymyxin B, an inhibitor of LPS. Furthermore, the immunization of mice with gamma-PGA NPs carrying ovalbumin (OVA) as an antigen significantly induced antigen-specific CD8(+) T cells and antigen-specific production of interleukin-2, tumor necrosis factor alpha, and gamma interferon from the cells. Such activities of gamma-PGA NPs were more potent than those obtained with immunization with OVA plus aluminum hydroxide or OVA plus complete Freund's adjuvant. These results suggest that gamma-PGA NPs induce a CD8(+) T-cell response by activating innate immunity in a fashion different from that of LPS. Thus, gamma-PGA NPs may be an attractive candidate to be developed further as a vaccine adjuvant.
authors.affiliation: Division of Antiviral Chemotherapy, Center for Chronic Viral Disease, Graduate School of Medical and Dental Sciences, Kagoshima University, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hamasaki
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Uto
authors.forename: Takami
authors.initials: T
authors.lastname: Akagi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Akashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Baba
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007155:Immunologic Factors / Q000276:immunology / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles; D020411:Oligonucleotide Array Sequence Analysis; D010047:Ovalbumin / Q000276:immunology; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000276:immunology / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000187:drug effects / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D051193:Toll-Like Receptors; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D010047:Ovalbumin