title: Biochemical and proteomic characterization of retrovirus Gag based microparticles carrying melanoma antigens.
abstract: Extracellular vesicles are membraneous particles released by a variety of cells into the extracellular microenvironment. Retroviruses utilize the cellular vesiculation pathway for virus budding/assembly and the retrovirus Gag protein induces the spontaneous formation of microvesicles or virus-like particles (VLPs) when expressed in the mammalian cells. In this study, five different melanoma antigens, MAGEA4, MAGEA10, MART1, TRP1 and MCAM, were incorporated into the VLPs and their localization within the particles was determined. Our data show that the MAGEA4 and MAGEA10 proteins as well as MCAM are expressed on the surface of VLPs. The compartmentalization of exogenously expressed cancer antigens within the VLPs did not depend on the localization of the protein within the cell. Comparison of the protein content of VLPs by LC-MS/MS-based label-free quantitative proteomics showed that VLPs carrying different cancer antigens are very similar to each other, but differ to some extent from VLPs without recombinant antigen. We suggest that retrovirus Gag based virus-like particles carrying recombinant antigens have a potential to be used in cancer immunotherapy.
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Reet
authors.initials: R
authors.lastname: Kurg
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Olavi
authors.initials: O
authors.lastname: Reinsalu
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Sergei
authors.initials: S
authors.lastname: Jagur
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Kadri
authors.initials: K
authors.lastname: Õunap
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Liisi
authors.initials: L
authors.lastname: Võsa
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Sergo
authors.initials: S
authors.lastname: Kasvandik
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Estonia.
authors.forename: Kärt
authors.initials: K
authors.lastname: Padari
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Kiira
authors.initials: K
authors.lastname: Gildemann
authors.affiliation: Institute of Technology, University of Tartu, Estonia.
authors.forename: Mart
authors.initials: M
authors.lastname: Ustav
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D003470:Culture Media; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D007167:Immunotherapy / Q000379:methods; D009052:Leukemia Virus, Murine; D058950:Melanoma-Specific Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009369:Neoplasms / Q000628:therapy; D040901:Proteomics
chemical_list: D003470:Culture Media; D015683:Gene Products, gag; D058950:Melanoma-Specific Antigens