title: Enhanced in vivo gene expression mediated by listeriolysin O incorporated anionic LPDII: Its utility in cytotoxic T lymphocyte-inducing DNA vaccine.
abstract: Enhanced in vivo gene expression using non-viral vectors is a critical issue in gene therapy in general. Among the many potential utilities of non-viral vector-mediated gene delivery, its application in DNA-based vaccination is an attractive approach with several practical advantages over conventional vaccination. We have previously shown that the endosomolytic bacterial protein listeriolysin O (LLO) is capable of facilitating transfection in vitro using the LPDII (anionic liposome-polycation-DNA complexes) delivery system. In the present study we have extended and investigated the DNA delivery of LLO-containing LPDII to in vivo and evaluated its utility in DNA vaccination in mice. We further investigated the ability of this non-viral gene delivery system to elicit an immune response to a model antigen ovalbumin (OVA), particularly focusing on the OVA-specific CD8(+) cytotoxic T lymphocyte (CTL) response, after delivery of a plasmid containing the OVA cDNA. A DNA prime and protein boost protocol was employed to generate cytotoxic T cell responses. Our results show that increased in vitro and in vivo transfection efficiencies were observed when LLO was incorporated into LPDII. This LLO-LPDII formulation produced an enhanced functional antigen-specific CD8(+) T cell response in vivo compared to the heat-inactivated LLO-containing LPDII (HI-LLO-LPDII) formulation. Furthermore, a significantly higher CTL frequency was observed in the splenocytes isolated from the mice primed with LLO-LPDII by an enzyme-linked immunosorbent spot assay. Interferon-γ production upon specific stimulation by OVA-specific CD8(+) peptide was also significantly stronger with the inclusion of LLO into LPDII. These findings suggest that the LLO-containing LPDII system possesses noteworthy potential as a candidate carrier for DNA vaccine delivery.
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Xun
authors.initials: X
authors.lastname: Sun
authors.forename: Chester
authors.initials: C
authors.lastname: Provoda
authors.forename: Kyung-Dall
authors.initials: KD
authors.lastname: Lee
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism*; D007114:Immunization; D007275:Injections, Intravenous; D007371:Interferon-gamma / Q000378:metabolism; D008081:Liposomes; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011073:Polyamines; D000071228:Polyelectrolytes; D011994:Recombinant Proteins / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection / Q000379:methods*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D007371:Interferon-gamma; D008081:Liposomes; D010047:Ovalbumin; D011073:Polyamines; D000071228:Polyelectrolytes; D011994:Recombinant Proteins; D019444:Vaccines, DNA; C038705:hlyA protein, Listeria monocytogenes