<p>Oxidized carbon nanoparticles as an effective protein antigen delivery system targeting the cell-mediated immune response</p>

Abstract

Background: The demand for an effective vaccine delivery system that drives a suitable immune response is increasing. The oxidized carbon nanosphere (OCN), a negatively charged carbon nanoparticle, has the potential to fulfill this requirement because it can efficiently deliver macromolecules into cells and allows endosomal leakage. However, fundamental insights into how OCNs are taken up by antigen-presenting cells, and the intracellular behavior of delivered molecules is lacking. Furthermore, how immune responses are stimulated by OCN-mediated delivery has not been investigated. Purpose: In this study, the model protein antigen ovalbumin (OVA) was used to investigate the uptake mechanism and intracellular fate of OCN-mediated delivery of protein in macrophages. Moreover, the immune response triggered by OVA delivered by OCNs was characterized. Methods: Bone-marrow-derived macrophages (BMDMs) from mice were used to study antigen uptake and intracellular trafficking. Mice were immunized using OCN–OVA combined with known adjuvants, and the specific immune response was measured. Results: OCNs showed no cytotoxicity against BMDMs. OCN-mediated delivery of OVA into BMDMs was partially temperature independent process. Using specific inhibitors, it was revealed that intracellular delivery of OCN–OVA does not rely on phagocytosis or the clathrin- and lipid raft/caveolae-mediated pathways. Delivered OVA was found to colocalize with compartments containing MHC class I, but not with early endosomes, lysosomes, and autophagosomes. Immunization of OVA using OCNs in combination with the known adjuvant monophosphoryl lipid A specifically enhanced interferon gamma (IFNγ)- and granzyme B-producing cytotoxic T cells (CTLs). Conclusion: OCNs effectively delivered protein antigens into macrophages that localized with compartments containing MHC class I partially by the temperature independent, but not clathrin- and lipid raft/caveolae-mediated pathways. Increased CD8 + T-cell activity was induced by OCN-delivered antigens, suggesting antigen processing toward antigen presentation for CTLs. Taken together, OCNs are a potential protein antigen delivery system that stimulates the cell-mediated immune response.

An Overview of Nanocarrier-Based Adjuvants for Vaccine Delivery

“…Oxidized carbon nanosphere (OCN), a negatively charged carbon nanoparticle was formulated and investigated for in vitro antigen uptake and ability to generate in vivo immune response. Subcutaneous immunization of BALB/c mice with OCN and OVA as a model antigen, demonstrated improved cell-mediated immune response by elevating antigen-specific CD8+ T cells while localizing in MHC class I compartments [ 144 ]. The potential of quantum dots (QDs) as fluorescent nanoparticles for in vitro and in vivo imaging of DCs is widely explored whereas an antigen-delivery system to enhance DC-mediated immune responses is being investigated.…”

Kinetics of Drug Release via Nicardipine Hydrochloride‐loaded Carboxymethyl Cellulose/Poly(D,L‐lactic‐co‐glycolic acid) Nanocarriers Using a Contemporary Emulsion Process

“…JCRB1093). It was maintained in DMEM supplemented with 10% FBS at humidified 5 % CO 2 atmosphere and 37 °C for 4 hr [53] …”

“…It was maintained in DMEM supplemented with 10% FBS at humidified 5 % CO 2 atmosphere and 37°C for 4 hr. [53] Cytotoxicity assay of the NCH-CMC/PLGA nanocarriers The cytotoxicity of the NCH-CMC/PLGA nanocarriers was assessed the cell viability by the MTT assay. PSVK1 cells were seeded onto the 96-well plate (density: 1.0 × 10 4 cells/well) and an overnight incubated at 37°C and 5% CO 2 .…”

Unravelling the interactions of biodegradable dendritic nucleic acid carriers and neural cells

“…As no major impact on cells was noted after 0.5 h, this was the selected incubation time to proceed with the study. 33,38 When incubated with MBCD, there was a reduction in the internalization of dendriplexes even at the lowest concentration tested (20 µM). Above 1000 µM, the blocking of internalization was practically complete.…”