Efficient activation of human blood monocytes to a tumoricidal state by liposomes containing human recombinant gamma interferon.
Human recombinant gamma interferon (INF-gamma) activated human peripheral blood monocytes to a cytotoxic state capable of lysing adherent tumorigenic cells without harming normal cells. The efficiency of INF-gamma activation of monocytes is enhanced by encapsulating INF-gamma within liposomes: The minimum effective dose (MED) of free INF-gamma for monocyte activation was found to be 1-10 U/ml, per 10(5) monocytes, whereas the minimum dose for IFN-gamma encapsulated in liposomes was less than 0.0025 U. Monocytes treated with liposome-encapsulated INF-gamma retained their cytotoxic phenotype for much longer than do monocytes treated with free INF-gamma. Since liposomes can be passively targeted to cells of the reticuloendothelial system following IV administration, these findings suggest that liposome-encapsulated INF-gamma may have therapeutic potential that should be evaluated in vivo.
D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D004274:DNA, Recombinant; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007167:Immunotherapy; D007371:Interferon-gamma / Q000008:administration & dosage*; D008081:Liposomes / Q000008:administration & dosage; D009000:Monocytes / Q000276:immunology*; D009374:Neoplasms, Experimental / Q000628:therapy*; D013997:Time Factors
D004274:DNA, Recombinant; D008081:Liposomes; D007371:Interferon-gamma