SUSTAINED CYTOKINE DELIVERY FOR ANTICANCER VACCINATION - LIPOSOMES ASALTERNATIVE FOR GENE-TRANSFECTED TUMOR-CELLS

Vaccination with tumor cells genetically engineered to produce interle ukin (IL)-2 is an attractive strategy to enhance antitumor immune resp onses. The improved antitumor immunity upon vaccination with IL-2 gene -modified tumor cells may be due to the prolonged presence of the cyto kine at the vaccination site. Because liposomes have been used for sus tained delivery of a variety of agents, we compared the protective eff ect of vaccines consisting of IL-2 gene-modified B16 melanoma cells to that of vaccines composed of IL-2 liposomes and irradiated melanoma c ells. The results indicate that both approaches equally protect agains t a lethal challenge with B16 melanoma cells. More than 20% of the pro tected animals developed vitiligo at the vaccination and/or tumor chal lenge site.