Activation of natural killer T cells by liposomal glycosphingolipids increases the efficacy of liposomal doxorubicin against DMBA-induced tumors in mice (VAC10P.968)

Natural Killer T (NKT) cells show potent antitumor activity upon activation with their specific ligands. Glycosphingolipids (GSLs) isolated from Sphingomonas paucimobilis were incorporated into DPPC-liposomes to prepare GSL-incorporated liposomes (GSL-liposomes). Treatment of tumor-bearing mice with a combination of GSL-liposomes and doxorubicin liposomes resulted into slowing down of the progression of tumors and increase in the survival of mice. Splenocytes obtained from mice treated with GSL-liposomes produced higher levels of IFN-γ and IL-12 compared to mice that did not receive GSL-liposomes. Mice pretreated with GSL-liposomes showed low frequency of tumors after DMBA exposure. These findings suggest that co-administration of NKT cells activating GSL-liposomes and anti-cancer drug loaded liposomes may be proved a better option for the treatment of cancer.