title: Modified vaccinia virus Ankara delivers a robust surrogate marker for immune monitoring to sarcoma cells even if cells are being exposed to chemotherapy and heat treatment.
abstract: OBJECTIVE
  Adding hyperthermia to chemotherapy improved the clinical outcome of patients with high risk soft tissue sarcoma. Further improvement might be possible if combined with vaccination strategies. As no sarcoma-associated antigens are known, the ectopic expression of a surrogate marker for which immune monitoring tools are available, is envisaged. We tested surrogate marker transfer into sarcoma cells in vitro using modified vaccinia virus Ankara (MVA), which has well established clinical safety. We examined its robustness against standard sarcoma treatment modalities, such as ifosfamide and hyperthermia.
  
  
  METHODS
  We transduced sarcoma cell lines and primary tumour cells from sarcoma patients with MVA encoding the human tyrosinase gene (MVA-hTyr). Kinetics of tyrosinase expression and the potency to activate tyrosinase-specific cytotoxic T cells were assessed. In addition cells were exposed to chemotherapy and heat, imitating the clinical setting.
  
  
  RESULTS
  Tyrosinase was ectopically expressed in sarcoma cells. Infected cells presented tyrosinase epitopes for T cell recognition even if exposed to ifosfamide/heat.
  
  
  CONCLUSIONS
  As sarcoma patients receive surgery up front or after neoadjuvant systemic chemotherapy/hyperthermia, tumour material is generally available. Our data document that primary sarcoma cells can be infected with MVA-hTyr in vitro and antigen presentation is not affected by ifosfamide or heat treatment. Infected cells can serve as a source for vaccine preparation. MVA-hTyr infection of tumour cells lacking defined antigens is a feasible system to introduce a robust surrogate marker to provide an immune monitoring marker for assessing the induction of antigen-specific T cell activation.
authors.affiliation: Department of Internal Medicine III, Klinikum Grosshadern Medical Centre, Ludwig Maximilians University, Marchioninistrasse 25, Munich, Germany. Katharina.Lechner@med.uni-muenchen.de
authors.forename: Katharina
authors.initials: K
authors.lastname: Tschoep-Lechner
authors.forename: Ingo
authors.initials: I
authors.lastname: Drexler
authors.forename: Doreen
authors.initials: D
authors.lastname: Hammer
authors.forename: Daniel
authors.initials: D
authors.lastname: Neumann
authors.forename: Heike
authors.initials: H
authors.lastname: Pohla
authors.forename: Gerd
authors.initials: G
authors.lastname: Sutter
authors.forename: Elfriede
authors.initials: E
authors.lastname: Noessner
authors.forename: Rolf-Dieter
authors.initials: RD
authors.lastname: Issels
mesh_terms: D017951:Antigen Presentation; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival; D049452:Green Fluorescent Proteins / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D007069:Ifosfamide / Q000494:pharmacology*; D007371:Interferon-gamma / Q000276:immunology; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000276:immunology*; D012509:Sarcoma / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured; D014615:Vaccinia / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D018906:Antineoplastic Agents, Alkylating; D049452:Green Fluorescent Proteins; D007371:Interferon-gamma; D014442:Monophenol Monooxygenase; D007069:Ifosfamide