Intratumoral IL-7 delivery by mesenchymal stromal cells potentiates IFNγ-transduced tumor cell immunotherapy of experimental glioma

The present study reports regression of pre-established experimental rat gliomas as a result of combining peripheral immunization using interferon gamma (IFNγ) transduced autologous tumor cells with local intratumoral delivery of interleukin 7 (IL-7) by mesenchymal stromal cells. IL-7 alone significantly decreased the tumor area and this effect was enhanced with IFNγ immunization. A higher density of intratumoral T-cells was observed in animals receiving combined therapies compared to rats receiving either cytokine alone suggesting that the therapeutic effect is dependent on a T-cell response.