Characterization of nickel-decorated PLGA particles anchored with a his-tagged polycation.

The pharmacological impact of oligodeoxynucleotides (ODN) as transcription factors decoys (anti-sense) depends on the efficiency of cellular uptake. In this study, we sought to generate nickel-decorated particles to facilitate the entry of ODN into dendritic cells (DCs), the primary instigators of immune responses. Nickel ions were incorporated into the matrix of poly(D,L-lactide-co-glycolide) (PLGA) particles using the metal chelating lipid DOGS-NTA-Ni.

Expansion of Foxp3-expressing regulatory T cells in vitro by dendritic cells modified with polymeric particles carrying a plasmid encoding interleukin-10.

An emerging focus in experimental gene therapy is to employ non-viral vectors to deliver immunosuppressive cytokines aimed at attenuating damaging immune responses toward auto and alloantigens. In the current study, we present data showing that poly(lactic-co-glycolic acid) (PLGA) particles modified with the cationic peptide O10H6 (PLGA(O10H6)) were effective in delivering a mouse IL-10 encoding plasmid (pIL10) to skew bone marrow-derived dendritic cells (DCs) to downregulate T cell responses. T cells stimulated by the IL-10 gene-modified DCs exhibited characteristics of regulatory T (Treg) cells, as evident by upregulation of Foxp3 transcription factor concomitant with an increase in TGFbeta production.

Characterization of particles fabricated with poly(D, L-lactic-co-glycolic acid) and an ornithine-histidine peptide as carriers of oligodeoxynucleotide for delivery into primary dendritic cells.

We report the formulation of particles to deliver oligodeoxynucleotides (ODN) into primary murine dendritic cells (DCs), the most potent antigen-presenting cells (APCs) known, using poly(D,L-lactic-co-glycolic acid) (PLGA) and a small cationic peptide. PLGA polymer and the ODN were fabricated into nano-sized spherical particles with the aid of O10H6 (O = ornithine, H = histidine). We have previously determined that O10H6 condenses DNA and is less toxic to DCs than a similar lysine-based peptide.

Secondary anchor substitutions in an HLA-A*0201-restricted T-cell epitope derived from Her-2/neu.

We investigated analogues of GP2 (IISAVVGIL), an HLA-A*0201-restricted T-cell epitope derived from residues 654-662 in the tumor-associated antigen (TAA) Her-2/neu. One limiting factor of GP2 is its poor affinity for HLA-A*0201. Conformational analysis revealed the P5-P7 region in GP2 appears to be linked to the stability of P9 side chain interaction with the MHC molecule.

Attenuated alloreactivity of dendritic cells engineered with surface-modified microspheres carrying a plasmid encoding interleukin-10.

In the present study, we investigated MS(O10H6) as a carrier system to introduce a plasmid encoding murine interleukin-10 (pIL-10) to modulate alloreactivity of dendritic cells (DC). Results indicate that MS(O10H6) formed stable and protective nano-sized particles with pIL-10. Gene-modified DC elicited weak proliferation of allogeneic CD4 and CD8 T cells in vitro.

Polymeric microspheres as stabilizing anchors for oligonucleotide delivery to dendritic cells.

The aim of this study is to evaluate a novel microspheric vector for delivery of oligonucleotides (ODN) into dendritic cells (DC). A requirement of decoy-based modulation of transcriptional activities in DC is that the ODN would have to accumulate inside the cell. Using an ex vivo DC culture model, we demonstrate that anionic microspheres (MS) coated with an ornithine/histadine-based cationic peptide (O10H6) is an effective carrier of short ODN.

Gene delivery to dendritic cells facilitated by a tumor necrosis factor alpha-competing peptide.

Efficient gene delivery systems tailor-designed for dendritic cells (DCs) would allow the possibility of therapeutic manipulation of a wide spectrum of immune functions. Toward achieving this goal, we have identified a novel heptameric peptide (YTYQGKL) that functions as a localization moiety to mediate gene transfer in murine DCs. The sequence was identified by screening a phage display library against a DC cell line (JAWSII) using mouse TNFalpha as the eluting ligand.

A cationic peptide consists of ornithine and histidine repeats augments gene transfer in dendritic cells.

Condensing the plasmid with high molecular weight cationic polymers such as poly-L-lysine (PLL) and poly-L-ornithine (PLO) can enhance antigen-specific immunity generated from genetic vaccination with naked DNA encoding antigens. While these high molecular weight polymers are clearly effective in transfection experiments, clinical applications are limited by their physical heterogeneity and toxicity. Three chemically defined low molecular weight cationic peptides, K(16), K(10)H(6), and O(10)H(6), were examined in the context of DNA binding, toxicity, and efficiency of gene transfer in dendritic cells (DC).