title: Immunisation with modified HPV16 E7 genes against mouse oncogenic TC-1 cell sublines with downregulated expression of MHC class I molecules.
abstract: Human papillomavirus type 16 (HPV16)-transformed mouse TC-1 cells are extensively used in the evaluation of efficacy of experimental vaccines against tumours induced by HPVs. As these cells strongly express MHC class I molecules and downregulation of MHC class I surface expression is one of the important mechanisms that enable tumour escape from the host immune system, we undertook to derive TC-1 clones with reduced expression of MHC class I antigens. TC-1 cells were inoculated into mice preimmunised with an E7 gene-based DNA vaccine and from tumours developing in a portion of the animals, cell clones with downregulated MHC class I surface expression were isolated. Treatment with IFN-gamma resulted in an upregulation of MHC class I molecules in these cells, but after IFN-gamma removal, their expression gradually dropped again. When the expression of some components of the antigen-processing machinery (APM; LMP-2, TAP-1, and TAP-2) was tested, a reduced TAP-1 production was detected in cell lines with downregulated MHC class I expression. An enhanced immunoresistance of TC-1-derived clones with reduced MHC class I expression was observed in animals immunised with plasmids carrying modified E7 genes. Apart from the previously described fusion gene Sig/E7/LAMP-1, a new construct, Sig/E7GGG/LAMP-1, with a mutated Rb-binding site, was also used for immunisation. No significant change of immunogenicity was recorded for Sig/E7GGG/LAMP-1. Cell lines with downregulated MHC class I expression derived from TC-1 cells may represent a useful model for testing therapeutic anti-HPV vaccines in settings more relevant to clinical requirements.
authors.affiliation: Department of Experimental Virology, Institute of Hematology and Blood Transfusion, U nemocnice 1, 128 20 Prague 2, Czech Republic. smahel@uhkt.cz
authors.forename: Michal
authors.initials: M
authors.lastname: Smahel
authors.forename: Pavel
authors.initials: P
authors.lastname: Síma
authors.forename: Viera
authors.initials: V
authors.lastname: Ludvíková
authors.forename: Iuri
authors.initials: I
authors.lastname: Marinov
authors.forename: Dana
authors.initials: D
authors.lastname: Pokorná
authors.forename: Vladimír
authors.initials: V
authors.lastname: Vonka
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000276:immunology*; D019470:Biolistics; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use*; D002461:Cell Line, Transformed / Q000276:immunology / Q000637:transplantation; D002472:Cell Transformation, Viral; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005805:Genes, MHC Class I; D005813:Genes, Synthetic; D011905:Genes, ras; D006183:H-2 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D007114:Immunization; D016233:Immunotherapy, Active; D007371:Interferon-gamma / Q000494:pharmacology; D008168:Lung; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology / Q000517:prevention & control*; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D027383:Papillomaviridae / Q000235:genetics / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D019444:Vaccines, DNA / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; C068651:E6 protein, Human papillomavirus type 16; D006183:H-2 Antigens; C024755:H-2K(K) antigen; C032876:H-2Kb protein, mouse; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D019444:Vaccines, DNA; C059731:oncogene protein E7, Human papillomavirus type 16; D007371:Interferon-gamma