Studies On Three Melanoma Vaccine Delivery Systems

In this paper, three vectors of delivery protein antigens (simple liposomes, membrane fusogenic liposomes, and reconstituted Sendai virosomes) were prepared. Simple liposomes act not only as vaccine delivery vector, but also as immune adjuvant. Membrane fusogenic liposomes and reconstituted Sendai virosomes can specifically deliver encapsulated protein antigens into cytoplasm with membrane fusion manner by the mechanism that virus infect cells. On the surface of the virus membrane, two major proteins are involved in cellular infection. Hemagglutinating and Neuraminidase (HANA) proteins are required to bind a receptor (sialic acid) on the cell surface. In addition, Fusion (F) protein interacts with the lipid layer of the cell membrane to induce cell fusion.In this study, the protein antigens, which are mixing proteins extracted from culture B16 melanoma cells by ammonium sulphate gradient precipitation, encapsulated in three vectors respectively, and three melanoma vaccines were prepared. Physico-chemical properties, envelopment efficiency, stability, release rule in vitro, safty and pharmacodynamics were investigated.The tumor vaccine based on the vector of liposomes was prepared by encapsulating mixing proteins extracted from B16 melanoma cells into simple liposomes, which were prepared with cholesterol and lecithin. Physico-chemical properties, envelopment efficiency, stability and release rule in vitro were observed. After the melanoma mice were immunized with three dosage groups, celluar and systemic responses, tumor suppression and tumor challenge were investigated. The results indicated that the size distribution of the melanoma vaccine based on the vector of simple liposomes was uniformly (approximately 110 nm). Envelopment efficiency (method I : 10.6±1.51; method II : 8.3 + 0.78 ) and release in vitro (method 1:41%; method II : 25%) were low. Vaccine in nitrogen-filled, umber ampoule that was stored in 4℃ for 6 months, was stable. After the mice were immunized, systemic immune response can be induced, but not CTL response. After tumor challenging, the tumor growing was suppressed, and the rate of successful inoculation was decreased, and survival time was prolonged.The vaccine based on the vector of membrane fusogenic liposomes was prepared by ultraviolet inactive Sendai virus fusing with the conventional liposomes formulated vaccine. Physico-chemical properties, envelopment efficiency, stability and release rule in vitro were investigated. The kinetics of fusion between liposomes and virus in different temperatures was determined by fluorescence self-quenching of octadecyl Rhodamine B chloride. After the melanoma mice were immunized with three dosage groups, celluar and systemic responses,tumor suppression and tumor challenge were studied. The results suggested that the size distribution of the melanoma vaccine based on the vector of membrane fusogenic liposomes was uniformly (approximately 200 nm). Envelopment efficiency (method I : 11.4+2.40; method II : 8.07 +0.40 ) and release in vitro (method I : 33%; method II: 21%) were low. Vaccine in nitrogen-filled, umber ampoule that was stored in 4C for 6 months, was stable. The kinetics of fusion was best in 37C. After the mice were immunized, systemic and strong CTL responses were induced. After tumor challenging, the tumor growing was suppressed significantly, and the rate of successful inoculation was decreased, and survival time was prolonged.The tumor vaccine based on the vector of reconstituted Sendai virosomes was prepared by encapsulating mixing proteins extracted from B]6 melanoma cells into reconstituted Sendai virosomes, which were prepared by extracting detergent method. Physico-chemical properties, envelopment efficiency, stability and release rule in vitro were investigated. After the melanoma mice were immunized with three dosage groups, celluar and systemic responses, tumor suppression and tumor challenge were studied. The results suggested that the size distribution of the melanoma vaccine based on the vector of reconsti...