Nanoparticles built by self-assembly of amphiphilic γ-PGA can deliver antigens to antigen-presenting cells with high efficiency: A new tumor-vaccine carrier for eliciting effector T cells

Yoshikawa, Tomoaki; Okada, Naoki; Oda, Atsushi; Matsuo, Keisuke; Matsuo, Keitaro; Kayamuro, Hiroyuki; Ishii, Yumiko; Yoshinaga, Tomoaki; Akagi, Takami; Akashi, Mitsuru; Nakagawa, Shinsaku

doi:10.1016/j.vaccine.2007.12.037

Cited by 83 publications

(44 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, reports on the effect of charge on cellular uptake and immune stimulation of polymer-DNA particles are conflicting. Studies have shown that both negatively charged and positively charged particulates have high transfection capabilities and are able to induce immune responses [34,36], suggesting that the charge may have no significant effect on the immunostimulatory properties of polymer-DNA complexes.The immunostimulatory PEI polymers assessed in the present study, namely M25, L22, L87, and JET, shared physical properties that were distinct from the L25 PEI polymer that did not enhance immune responses. The complexes of DNA with the immunostimulatory polymers were smaller (110-150 nm) than those made with the nonstimulatory polymer (200 nm).…”

mentioning

confidence: 99%

Enhancement of plasmid DNA immunogenicity with linear polyethylenimine

et al. 2012

View full text Add to dashboard Cite

The utility of plasmid DNA as an immunogen has been limited by its weak immunogenicity. In the present study, we evaluated the ability of a family of linear polyethylenimine (PEI) polymers, complexed to plasmid DNA, to augment DNA expression in vivo and to enhance antigen-specific adaptive immune responses. We showed that four of five structurally different PEIs that we evaluated increased in vivo DNA expression 20-to 400-fold, and enhanced DNA-induced epitope-specific CD8 IntroductionDNA vaccine constructs have been evaluated and are being tested in a number of human clinical trials for generating immunity to many types of diseases, including infectious, cancer, allergic, and autoimmune diseases [1,2]. In addition, the use of DNA vaccinesCorrespondence: Dr. Evita V. Grant e-mail: evita.grant@gmail.com has proven effective in some current veterinary products such as a vaccine against infectious hematopoietic necrosis virus for salmon [3], melanoma immunotherapeutic vaccine for dogs [4] and a vaccine against the West Nile Virus for horses [5]. Unfortunately, the immunogenicity of plasmid DNA in humans has proven to be modest in comparison with the immunogenicity observed in other species of microbial expression vectors. Consequently, efforts are being made to increase the immunogenicity of DNA vaccine constructs. Strategies have been developed to increase plasmid DNA expression via codon modification [6], the use of enhanced promoters [7] and the use of microbial transcriptional C 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.eji-journal.eu 2938 Evita V. Grant et al. Eur. J. Immunol. 2012. 42: 2937-2948 control elements [8]. Since plasmid DNA has poor in vivo transfection efficiency, a number of formulations of plasmid DNA have been evaluated to protect DNA from degradation and to enhance transfection efficiency [9][10][11]. The "gene gun" technology [12] was developed to enhance DNA delivery and immunogenicity. Furthermore, immunomodulation strategies have been evaluated for their ability to enhance DNA immunogenicity [13][14][15]. The synthetic polycationic polymer polyethylenimine (PEI), consisting of chains of ethylenimine units-CH 2 CH 2 NH-, has become the gold standard for enhancing the in vivo expression of administered genes [16,17]. PEI is superior to other nonmicrobial transfection agents because of its ability to protect DNA from degradation [18], to escape intracellular endosomal lysis [19] and to efficiently deliver DNA into the nucleus of cells [20]. Formulation with PEI polymers has been employed in DNA-and siRNAbased immunotherapy against cancer [21,22] and in vaccination studies targeting different infectious agents [10,23,24].In the present study, we have evaluated the physicochemical characteristics of a series of PEI polymers and have assessed associations between particular characteristics of these polymers and their ability to facilitate in vivo DNA expression and enhanced adaptive immune responses. Moreover, we have examined plasmid DNA constructs formulated with these various PEI...

show abstract

mentioning

confidence: 99%

Enhancement of plasmid DNA immunogenicity with linear polyethylenimine

et al. 2012

View full text Add to dashboard Cite

show abstract

“…We previously reported that DCs loaded with g-PGA NPs containing entrapped antigens enhance antigen presentation via MHC class I molecules by delivering the antigens to the DC cytosol. 8,9) It was unclear, however, whether g-PGA NPs affect DC maturation, and whether DCs loaded with TAA using g-PGA NPs more effectively induce TAA-specific CTL production and the anti-tumor response. Thus, in the present study, we investigated the characteristics and utility of g-PGA NPs as antigen delivery carriers in DC-based cancer immunotherapy.…”

Section: )mentioning

confidence: 99%

“…CTL Assay The CTL assay was performed according to the previously described method. 8) One week after DC-immunization, splenocytes isolated from immunized mice were re-stimulated with E.G7-OVA cells that had been inactivated using mitomycin C. Five days later, the splenocytes were collected as effector cells. The cytotoxic activity of the effector cells was assessed by a 51 Cr-release assay using E.G7-OVA or EL4 cells as targets, and was determined using the following formula: % of lysisϭ(counts of experimental 51 CrreleaseϪcounts of spontaneous 51 Cr-release)/(counts of maximum 51 Cr-releaseϪcounts of spontaneous 51 Cr-release)ϫ 100.…”

Section: Mice and Cellsmentioning

confidence: 99%

The Utility of Poly(.GAMMA.-glutamic acid) Nanoparticles as Antigen Delivery Carriers in Dendritic Cell-Based Cancer Immunotherapy

Matsuo

Ishii

Matsuo

et al. 2010

Biological & Pharmaceutical Bulletin

Self Cite

View full text Add to dashboard Cite

The efficacies of cancer immunotherapy approaches are determined by their ability to induce tumor-specific cytotoxic T-lymphocytes (CTLs), which are major effector cells in tumor immunity. One approach to fighting cancer that is gaining popularity among tumor immunologists is immunization of cancer patients with autologous dendritic cells (DCs) loaded ex vivo with tumor-associated antigens (TAAs). 1)DCs are unique professional antigen-presenting cells (APCs) capable of priming CTLs and helper T cells (Th) by presenting antigens via major histocompatibility complex (MHC) class I and II molecules, followed by co-stimulatory signals. In this regard, an essential event in the generation of effective tumor immunity is the efficient display of antigenic fragments by MHC class I molecules, which can prime and expand CTLs on the surface of manipulated DCs for immunization. MHC class I-presented peptides are usually derived from endogenous antigens synthesized by cells, including DCs. Antigens in the extracellular fluids do not gain access to the MHC class I-pathway in most cells and thus fail to be presented. DCs are capable of presenting exogenous antigens on MHC class I molecules in a process that is called "crosspresentation," and this process is markedly enhanced when the antigen is internalized by phagocytosis, 2) macropinocytosis, 3) or receptor-mediated endocytosis. 4,5) Therefore, the development of a non-cytotoxic and efficient method to deliver antigens to the MHC class I-pathway in DCs is essential for improving the efficacy of DC-based cancer immunotherapy.Immature DCs situated in peripheral tissues serve as sentinels to immunologic threats and actively internalize particulate antigens such as bacteria and viruses.6,7) Based on this characteristic, the particulate antigen delivery system is thought to be ideal for generating cross-presentation in DCs. We developed biodegradable nanoparticles comprising amphiphilic poly(g-glutamic acid) (g-PGA NPs) that can efficiently entrap various proteins. We previously reported that DCs loaded with g-PGA NPs containing entrapped antigens enhance antigen presentation via MHC class I molecules by delivering the antigens to the DC cytosol. 8,9) It was unclear, however, whether g-PGA NPs affect DC maturation, and whether DCs loaded with TAA using g-PGA NPs more effectively induce TAA-specific CTL production and the anti-tumor response. Thus, in the present study, we investigated the characteristics and utility of g-PGA NPs as antigen delivery carriers in DC-based cancer immunotherapy. MATERIALS AND METHODSMice and Cells Female C57BL/6 mice (7 weeks of age) were purchased from Japan SLC Inc. (Hamamatsu, Japan). OT-I T cell receptor-transgenic mice specific for ovalbumin (OVA) (257)(258)(259)(260)(261)(262)(263)(264) presented by H-2K b and OT-II T cell receptortransgenic mice specific for OVA (323)(324)(325)(326)(327)(328)(329)(330)(331)(332)(333)(334)(335)(336)(337)(338)(339) presented by I-A b were purchased from Jackson Laboratory (Bar Harbor, ME, U.S.A.). Animal experimen...

show abstract

“…[9][10][11][12][13] Recent studies have proposed medical applications for PGA. [14][15][16][17][18][19] The pgsBCAywtC operon of B. subtilis (natto) directs PGA synthesis, 1,20,21) and the gene products PgsB, C, A, and YwtC are thought to form a PGA synthetase complex in the cytoplasmic membrane. 1,3) PgsB is an ADP-forming ATPase belonging to the MruD family, and is considered to have a catalytic center for polymerization.…”

Section: -3)mentioning

confidence: 99%