Improved antitumour immunity in murine neuroblastoma using a combination of IL-2 and IL-12

Abstract

Neuroblastoma immunotherapy using cytokine-modified tumour cells has been tested in clinical trials. However, because of the complex nature of antitumour immune responses, a number of therapies may be required for complete tumour eradication and generation of systemic immunity. We report here the improved antitumour effect of two cytokines, interleukin-2 (IL-2) and interleukin-12 (IL-12), when coexpressed by neuroblastoma cell lines. Initially, transfection of human and mouse neuroblastoma cell lines resulted in high expression levels of biologically active IL-2 and IL-12 in vitro. These cytokines when expressed by transfected Neuro-2A cells completely abolished their in vivo tumorigenicity in a syngeneic neuroblastoma model. Vaccination of established tumours with IL-12-producing cells exhibited a clear effect with reduced tumour growth in the presence of IL-2. In vivo depletion studies showed that CD4 þ and CD8 þ T cells mediate the response against cytokine-producing cells. These results suggest that IL-2 and IL-12, when cotransfected in tumour cells, are effective against established disease and provide a promising immunotherapeutic approach for the treatment of neuroblastoma.

Immunotherapy for neuroblastoma using syngeneic fibroblasts transfected with IL-2 and IL-12

“…Peak cytokine levels from cytokinetransfected AJ3. (Siapati et al, 2003). For vaccine studies, a large population of cells was transfected, and stored frozen so that the same cellular vaccine was used in all experiments.…”

“…In this study, we have evaluated the potential of a vaccine consisting of syngeneic fibroblasts for immunotherapy in a murine model of neuroblastoma and compared this vaccine with a neuroblastoma tumour cell vaccine described previously (Siapati et al, 2003). The A/J mouse and syngeneic Neuro-2A cells are widely used by neuroblastoma researchers and they are considered to represent a good model of the disease (Ziegler et al, 1997).…”

“…Human IL-2 gene was expressed from pCI-hIL-2 (Siapati et al, 2003). Murine IL-12 was expressed from the plasmid pCI-mIL-12, which was generated by subcloning into pCI (Promega, Southampton, UK) the gene encoding the single-chain fusion protein of the p35 and p40 subunits of murine IL-12 separated by a flexible linker, from plasmid pcDNA3.1scIL12 (Lode et al, 1998a).…”

“…Interleukin-12 also induces CD25 expression on T cells, thereby enhancing their proliferation in response to IL-2 (Nguyen et al, 2000). We have demonstrated previously that Neuro-2A murine neuroblastoma cells could be transfected simultaneously with two plasmids using a synthetic vector system to express high levels of both IL-2 and single-chain IL-12 (Siapati et al, 2003). Transfection of Neuro-2A cells with IL-2 and IL-12 abolished their tumorigenicity in syngeneic A/J mice, and when injected into established tumours provoked an antitumour immune response involving CD8 þ and CD4 þ T cells, which led in some cases to complete tumour eradication.…”

Fenretinide sensitizes multidrug-resistant human neuroblastoma cells to antibody-independent and ch14.18-mediated NK cell cytotoxicity

“…Cytokines such as interleukin-2 (IL-2), IL-12 [36], and IL-27 [37] either as a single agent or in combination have demonstrated antitumor efficacy in preclinical neuroblastoma models.…”