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Results obtained in this study demonstrated that incorporation of PEI augmented rAAV-mediated insulin gene transfer and enhanced amelioration of hyperglycemia in the STZ-induced diabetic animals.

Glucose- and metabolically controlled hepatic insulin gene therapy was obtained both in vitro and in vivo.

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The aim of this study was to investigate the use of tomatine adjuvant to deliver soluble antigen for crosspresentation by bone marrow-derived dendritic cells (BMDCs). BMDCs were incubated with tomatine adjuvantovalbumin (OVA) complex and analyzed for antigen uptake by flow cytometry. Adjuvant-induced cell death was examined in situ by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. To elucidate the effect of antigen internalization on tomatine adjuvant-mediated antigen presentation, BMDCs were treated with several endocytosis inhibitors, and antigen presentation was analyzed by B3Z activity assay. Our data indicated that tomatine adjuvant enhanced antigen internalization by antigen presenting cells (APCs) and induced significant cell death and leukocyte infiltration at the injection sites. In vitro tomatine adjuvant treatment of BMDCs activated Ova/K(b) restricted B3Z T cell hybridomas, whereas this activation was impaired by pretreatment with brefeldin A, cytochalasin B, wortmannin, or ZnCl2. Our results demonstrated the role of tomatine adjuvant in antigen delivery to antigen presenting cells (APCs) and suggested the involvement of phagocytosis and PI3K signaling during the delivery of soluble antigens in the context of MHC class I.

Poly(D,L-lactide) (PLA) microparticles containing the ovalbumin (OVA) model antigen were prepared by the double-emulsion and solvent evaporation method, followed by encapsulation with alternating layers of the polyelectrolytes, consisting of protamine sulfate and dextran sulfate of various molecular weights. The physicochemical properties, including particle size and zeta potentials, were characterised. Treatment of mouse macrophages with surface-modified PLA microparticles stimulated the generation of reactive oxygen species (ROS), such as hydrogen peroxide and superoxide, which was detected by the fluorescent probes, 2',7'-dichlorofluorescein diacetate (DCFH-DA) and hydroethidine (HE). Incubation of murine bone marrow-derived dendritic cells (BMDCs) with the encapsulated PLA microparticles enhanced the presentation of OVA soluble antigens in B3Z cells, an OVA-specific CD8(+) T cell hybridoma. Results obtained in this study demonstrated the potential use of polyelectrolyte-encapsulated biodegradable microparticles for delivery of soluble antigens to the antigen-presenting cells and stimulation of effective antigen presentation in the context of class I major histocompatibility complex.