title: Two Listeria monocytogenes vaccine vectors that express different molecular forms of human papilloma virus-16 (HPV-16) E7 induce qualitatively different T cell immunity that correlates with their ability to induce regression of established tumors immortalized by HPV-16.
abstract: Two recombinant Listeria monocytogenes (rLm) strains were produced that secrete the human papilloma virus-16 (HPV-16) E7 protein expressed in HPV-16-associated cervical cancer cells. One, Lm-E7, expresses and secretes E7 protein, whereas a second, Lm-LLO-E7, secretes E7 as a fusion protein joined to a nonhemolytic listeriolysin O (LLO). Lm-LLO-E7, but not Lm-E7, induces the regression of the E7-expressing tumor, TC-1, established in syngeneic C57BL/6 mice. Both recombinant E7-expressing rLm vaccines induce measurable anti-E7 CTL responses that stain positively for H-2D(b) E7 tetramers. Depletion of the CD8+ T cell subset before treatment abrogates the ability of Lm-LLO-E7 to impact on tumor growth. In addition, the rLm strains induce markedly different CD4+ T cell subsets. Depletion of the CD4+ T cell subset considerably reduces the ability of Lm-LLO-E7 to eliminate established TC-1 tumors. Surprisingly, the reverse is the case for Lm-E7, which becomes an effective anti-tumor immunotherapeutic in mice lacking this T cell subset. Ab-mediated depletion of TGF-beta and CD25+ cells improves the effectiveness of Lm-E7 treatment, suggesting that TGF-beta and CD25+ cells are in part responsible for this suppressive response. CD4+ T cells from mice immunized with Lm-E7 are capable of suppressing the ability of Lm-LLO-E7 to induce the regression of TC-1 when transferred to tumor-bearing mice. These studies demonstrate the complexity of L. monocytogenes-mediated tumor immunotherapy targeting the human tumor Ag, HPV-16 E7.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: G R
authors.initials: GR
authors.lastname: Gunn
authors.forename: A
authors.initials: A
authors.lastname: Zubair
authors.forename: C
authors.initials: C
authors.lastname: Peters
authors.forename: Z K
authors.initials: ZK
authors.lastname: Pan
authors.forename: T C
authors.initials: TC
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Paterson
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000276:immunology*; D001427:Bacterial Toxins; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000637:transplantation; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology*; D002461:Cell Line, Transformed / Q000276:immunology / Q000473:pathology / Q000821:virology; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015967:Gene Expression Regulation, Viral / Q000276:immunology; D005822:Genetic Vectors / Q000138:chemical synthesis / Q000276:immunology*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000276:immunology; D006460:Hemolysin Proteins; D006801:Humans; D007371:Interferon-gamma / Q000502:physiology; D008089:Listeria monocytogenes / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D027383:Papillomaviridae / Q000235:genetics / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000473:pathology / Q000821:virology; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
chemical_list: D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D019496:Cancer Vaccines; D018984:Epitopes, T-Lymphocyte; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines; D016212:Transforming Growth Factor beta; D014614:Vaccines, Synthetic; C059731:oncogene protein E7, Human papillomavirus type 16; D007371:Interferon-gamma; C038705:hlyA protein, Listeria monocytogenes