title: PLGA-Listeriolysin O microspheres: Opening the gate for cytosolic delivery of cancer antigens.
abstract: Strategies for cancer protein vaccination largely aim to activate the cellular arm of the immune system against cancer cells. This approach, however, is limited since protein vaccines mostly activate the system's humoral arm instead. One way to overcome this problem is to enhance the cross-presentation of such proteins by antigen-presenting cells, which may consequently lead to intense cellular response. Here we examined the ability of listeriolysin O (LLO) incorporated into poly-lactic-co-glycolic acid (PLGA) microspheres to modify the cytosolic delivery of low molecular weight peptides and enhance their cross-presentation. PLGA microspheres were produced in a size suitable for uptake by phagocytic cells. The peptide encapsulation and release kinetics were improved by adding NaCl to the preparation. PLGA microspheres loaded with the antigenic peptide and incorporated with LLO were readily up-taken by phagocytic cells, which exhibited an increase in the expression of peptide-MHC-CI complexes on the cell surface. Furthermore, this system enhanced the activation of a specific T hybridoma cell line, thus simulating cytotoxic T cells. These results establish, for the first time, a proof of concept for the use of PLGA microspheres incorporated with a pore-forming agent and the antigen peptide of choice as a unique cancer protein vaccination delivery platform.
authors.affiliation: The Laboratory for Cancer Drug Delivery & Cell Based Technologies, Faculty of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Ariel
authors.initials: A
authors.lastname: Gilert
authors.affiliation: The Laboratory for Cancer Drug Delivery & Cell Based Technologies, Faculty of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Limor
authors.initials: L
authors.lastname: Baruch
authors.affiliation: The Laboratory for Cancer Drug Delivery & Cell Based Technologies, Faculty of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Tomer
authors.initials: T
authors.lastname: Bronshtein
authors.affiliation: The Laboratory for Cancer Drug Delivery & Cell Based Technologies, Faculty of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel. machlufm@tx.technion.ac.il.
authors.forename: Marcelle
authors.initials: M
authors.lastname: Machluf
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D000951:Antigens, Neoplasm / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry*; D001692:Biological Transport; D002470:Cell Survival; D045142:Cross-Priming; D003600:Cytosol / Q000378:metabolism*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D006360:Heat-Shock Proteins / Q000737:chemistry*; D006460:Hemolysin Proteins / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D051379:Mice; D008863:Microspheres; D010047:Ovalbumin / Q000276:immunology; D010455:Peptides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D010586:Phagocytes / Q000166:cytology / Q000276:immunology; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D000067996:RAW 264.7 Cells
chemical_list: D000951:Antigens, Neoplasm; D001427:Bacterial Toxins; D004337:Drug Carriers; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D010455:Peptides; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D010047:Ovalbumin; C038705:hlyA protein, Listeria monocytogenes
keywords: Cancer immunotherapy; Cross-presentation; Drug delivery; LLO; Microspheres; PLGA