title: Sequential immunogene therapy with interleukin-12- and interleukin-15-engineered neuroblastoma cells cures metastatic disease in syngeneic mice.
abstract: OBJECTIVE
  To investigate the potential synergistic effects of Neuro2a neuroblastoma cells engineered with IL-12 and/or IL-15 genes in improving survival of syngeneic mice bearing neuroblastoma metastatic disease.
  
  
  METHODS
  Neuro2a cells engineered with interleukin (IL)-12 (Neuro2a/IL-12), IL-15 (Neuro2a/IL-15), or both cytokines (Neuro2a/IL-12/IL-15) were injected s.c. in syngeneic A/J mice challenged i.v. with Neuro2a parental cells (Neuro2apc) using different schedules of administration in either preventive or therapeutic settings.
  
  
  RESULTS
  A single injection of Neuro2a/IL-12 or Neuro2a/IL-15 cells induced resistance to a subsequent i.v. Neuro2apc challenge in 45% and 28% of mice, respectively. Neuro2a/IL-12/IL-15 cells protected 28% of mice, showing no synergistic effect. However, sequential vaccination with Neuro2a/IL-12 (day -30) followed by Neuro2a/IL-15 (day -15) protected 71% of mice from subsequent challenge with Neuro2apc. A single dose of Neuro2a/IL-12 prolonged the mean survival time of mice bearing established metastatic neuroblastoma from 21 +/- 3 to 46 +/- 27 days but failed to cure mice, whereas Neuro2a/IL-15 or Neuro2a/IL-12/IL-15 were ineffective. However, sequential vaccination with Neuro2a/IL-12 (day +3) followed by Neuro2a/IL-15 (day +13) cured 43% of mice as assessed by histologic analysis of different organs from long-term surviving mice. CTL activity against Neuro2apc cells was observed in splenocytes from treated mice, and CD8(+) T-cell depletion abrogated the therapeutic effect of vaccination.
  
  
  CONCLUSIONS
  Sequential vaccination with IL-12- and IL-15-engineered neuroblastoma cells induced optimal preventive and therapeutic effects, which may be related to the Th1 priming effect of IL-12 followed by the enhancement of CD8(+) T-cell responses and their maintenance mediated by IL-15.
authors.affiliation: Laboratory of Immunopharmacology, Istituto Nazionale per la Ricerca sul Cancro, Largo Benzi 10, 16132 Genoa, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Croce
authors.forename: Raffaella
authors.initials: R
authors.lastname: Meazza
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Orengo
authors.forename: Luana
authors.initials: L
authors.lastname: Radić
authors.forename: Barbara
authors.initials: B
authors.lastname: De Giovanni
authors.forename: Claudio
authors.initials: C
authors.lastname: Gambini
authors.forename: Barbara
authors.initials: B
authors.lastname: Carlini
authors.forename: Vito
authors.initials: V
authors.lastname: Pistoia
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Mortara
authors.forename: Roberto S
authors.initials: RS
authors.lastname: Accolla
authors.forename: Maria Valeria
authors.initials: MV
authors.lastname: Corrias
authors.forename: Silvano
authors.initials: S
authors.lastname: Ferrini
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004195:Disease Models, Animal; D005260:Female; D005818:Genetic Engineering; D007167:Immunotherapy; D018664:Interleukin-12 / Q000235:genetics / Q000627:therapeutic use*; D019409:Interleukin-15 / Q000235:genetics / Q000627:therapeutic use*; D051379:Mice; D008805:Mice, Inbred A; D009447:Neuroblastoma / Q000235:genetics / Q000556:secondary / Q000628:therapy*; D015996:Survival Rate; D014407:Tumor Cells, Cultured
chemical_list: D019409:Interleukin-15; D018664:Interleukin-12