Potent in situ activation of murine lung macrophages and therapy of melanoma metastases by systemic administration of liposomes containing muramyltripeptide phosphatidylethanolamine and interferon gamma
Fidler, I.J.; Fan, D.; Ichinose, Y.
Invasion and Metastasis 9(2): 75-88
1989
ISSN/ISBN: 0251-1789 PMID: 2496047 Document Number: 329515
Mouse alveolar macrophages (Am) were rendered tumoricidal after the intravenous administration of liposomes containing muramyl tripeptide phosphatidyl-ethanolamine (MTP-PE), a lipophilic derivative of muramyl dipeptide. The addition of recombinant mouse interferon gamma (r-IFN-.gamma.) to the liposomes significantly potentiated this effect. This potentiation was also observed in therapeutic studies of mice bearing well-established spontaneous lung melanoma metastases. Multiple intravenous injections of liposomes containing both MTP-PE and r-IFN-.gamma. resulted in 70% survival in one group treated for small lung metastases and 50% in another group treated for large lung metastases. These data demonstrate that the presentation of r-IFN-.gamma. and MTP-PE in liposomes is more efficient in inducing the destruction of metastases than either agent administered alone.