Experimental Research On Induction Of Cytotoxic T Lymphocytes With Soluble Protein Antigen Entrapped In Cationic Liposomes

Objective:To determine whether soluble protein antigen entrapped in cationic liposomes? could induce specific CTL response, To explore the theory of using soluble protein antigen entrapped in cationic liposomes to treat?minimal residual disease in acute leukemia.Methods: In intro DCs were generated, their Morphology, phenotypes and Functions were investigated. soluble protein antigen was encapsulated in cationic liposomes prepared by ultrasonic-freeze-drying. Dendritic cells were pulsed with soluble protein antigen and with antigen encapsulated in cationic liposomes respectively,then induced specific CTLs. The cytotoxicity of CTL between the two antigen were compared with MTT.Result:(1).In intro mature DCs were generated successfully.(2.) Cationic liposomes were prepared with egg phosphatidylcholine, stearylamine and cholesterol by ultrasonic-freeze-drying method , then encapsulated antigen (3.) The cytotoxicity of CTL was significantly different among each group (P < 0.05) (effect target cell ratio: 20∶ 1, 5∶1).It was 69.96士5.42,38.83士5.42,20.74士5.37,16.32士6.11 and 52.90士8.88,35.69士5.92 ,14.30士5.57,11.30士 6.97,respectively induced with encapsulated antigen,soluble antigen and no antigen. Among these groups, encapsulated antigen group was the most efficacious, soluble antigen was second.(4)The cytotoxicity of CTL between different effect target cell ratio was without significantly difference. Conclusion: Human bone marrow mononuclear cells could be induced into mature DCs. Cationic liposomes can encapsulate soluble antigen. The cytotoxicity of CTL induced with encapsulated antigen was higher than cytotoxicity induced with soluble antigen. The use of soluble protein antigen entrapped in cationic liposomes to treat minimal residual disease in acute leukemia may be a practical and effective method.