BACKGROUND: Nanoparticles (NPs) prepared from biodegradable polymers, such as poly (D,L-lactic acid-co-glycolic acid) (PLGA), have been studied as vehicles for the delivery of antigens to phagocytes. This paper describes the preparation of antigen-loaded PLGA-NPs for efficient cross-priming. METHODS: NPs containing a similar amount of ovalbumin (OVA) but different sizes were produced using a micromixer-based W/O/W solvent evaporation procedure, and the efficiency of the NPs to induce the cross-presentation of OVA peptides were examined in dendritic cells (DCs). Cellular uptake and biodistribution studies were performed using fluorescein isothiocyanate (FITC)-loaded NPs in mice. RESULTS: The NPs in the range of 1.1~1.4microm in size were the most and almost equally efficient in inducing the cross-presentation of OVA peptides via H-2Kb molecules. Cellular uptake and biodistribution studies showed that opsonization of the NPs with mouse IgG greatly increased the percentage of FITC-positive cells in the spleen and lymph nodes. The major cell type of FITC-positive cells in the spleen was macrophages, whereas that of lymph nodes was DCs. CONCLUSION: These results show that IgG-opsonized PLGA-NPs with a mean size of 1.1microm would be the choice of biodegradable carriers for the targeted-delivery of protein antigens for cross-priming in vivo.
Animals ; Cross-Priming ; Dendritic Cells ; Fluorescein ; Immunoglobulin G ; Isothiocyanates ; Lactic Acid ; Lymph Nodes ; Macrophages ; Mice ; Nanoparticles ; Ovalbumin ; Ovum ; Peptides ; Phagocytes ; Polyglycolic Acid ; Polymers ; Spleen

BACKGROUND: EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. METHODS: C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of cytokine secretion. Normal myeloid-dendritic cell (DC) was ex vivo cultured from bone marrow hematopoietic stem cells of C57BL/6 mice with GM-CSF and IL-4 to analyze the DC uptake of dead tumor cells and to observe the effect of EY-6 on the normal DC. RESULTS: EY-6 killed the MC38 tumor cells in a dose dependent manner (25, 50 and 100 microM) with carleticulin induction. And EY-6 induced the secretion of IFN-gamma but not of TNF-alpha from the MC38 tumor cells. EY-6 did not kill the ex-vivo cultured DCs at the dose killing tumor cells and did slightly but not significantly induced the DC maturation. The OVA-specific cross-presentation ability of DC was not induced by chemical treatment (both MHC II and MHC I-restricted antigen presentation). CONCLUSION: Data indicate that the EY-6 induced tumor cell specific and immunological cell death by modulation of tumor cell phenotype and cytokine secretion favoring induction of specific immunity eliminating tumor cells.
Animals ; Bone Marrow ; Cell Death ; Colonic Neoplasms ; Cross-Priming ; Dendritic Cells ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Granulocyte-Macrophage Colony-Stimulating Factor ; Hematopoietic Stem Cells ; Homicide ; Interleukin-4 ; Mice ; Phenotype ; Tumor Necrosis Factor-alpha