A combined therapeutic modality with hyperthermia and locally administered rIFN-β inhibited the growth of B16 melanoma in association with the modulation of cellular infiltrates

Abstract

Murine B16-F10 melanoma was treated with local microwave hyperthermia, local injection of murine recombinant interferon-beta (rIFN-β) or a combination of both in order to investigate the augmentation of anti-proliferative effects with this combination treatment. Concerning the local modulation of immunological reactions of the host, local hyperthermia at 43°C for 15 min on murine melanoma caused remarkable infiltration of natural killer cells and local injection of rIFN-β led to considerable infiltration of T cells. When these two modalities were combined, the infiltration of NK cells completely disappeared and, instead, remarkable augmentation of T cell infiltration occurred. Synergistic suppressive effects on melanoma growth with occasional scar formation were seen with this combined modality. These results indicate that local hyperthermia with a combination of rIFN-β modulates local immune reactions of the host, and probably this immune reaction is partly involved in the course of the suppression of tumor growth.