Preparation Of Dendritic Cell-tumor Cell Fusion Vaccines And Experimental Studies On Its Antitumor Immunity

Objective:Dendritic cell is the most powerful antigen-presenting cells of theimmune system in the body, and plays an important role in tumorimmunotherapy. In this study, We induced differentiation of dendritic cellmaturation from mononuclear cells, which were isolated from mousebone marrow. Cell fusion technology of PEG was applied to get thefusion vaccines of mouse dendritic cells and tumor cells, then we studiedthe biological characteristics and the effect of antitumor function aboutdendritic cell-tumor cell fusion vaccines in mice. We expected toestablish a foundation of dendritic cell-tumor cell fusion vaccines forin-depth studies in vitro and vivo, and provide some theoretical guidancefor clinical application in the future.Methods:According to the adherent growth characteristics of monocytes, weseparated mononuclear cells from mouse bone marrow and cultured withadherent method, mature dendritic cells were induced differentiationdepending on co-cultured with rhGM-CSF、rhIL-4、TNF-a in vitro.Dendritic cells and3LL or B16tumor cells were fused by using of PEG, then the pure fusion vaccines were screened out through adherentincubate. The phenotype of Dendritic cells which were inducedmaturation and fusion vaccines was analyzed by FACS,3H-TdRincorporation method was used for the testing of dendritic cell and tumorcell fusion vaccines induced cytotoxic T lymphocytes (CTL) to tumorcells; the antitumor immune effect of dendritic cell-tumor cell fusionvaccines was detected on murine tumor models which were establishedby immunological methods.Results:1. Typical morphological characteristics of DC were harvest invitro of induction differentiation from healthy mouse bone marrow,mature DC expressed a high level of MHC II and CD86.2. It was succeed that DC were fused with lung cancer cells lines3LL or melanoma cell lines B16tumor cells in the presence of PEG.Control cells, DC and tumor cells expressed a corresponding antigen, andfusion cells both antigens were higher.3. The DC tumor fusion vaccine can effectively induce specifickilling of tumor cells by CTL cytotoxic activity, DC treated group and thetumor cells groups can not effectively induce antitumor cell cytotoxicactivity.4. The DC tumor fusion vaccine treatment group survival time ofmice with PBS, DC alone, tumor cells alone, DC and tumor cells injected with the control group compared to significantly prolong， tumor growthwas significantly inhibited,to96days, the survival rate B16group was80%,100%in the3LL lung cancer group.Conclusions:These studies stated clearly that mature DC could be acquired fromhealthy mouse bone marrow mononuclear cells by co-cultured withrhGM-CSF、rhIL-4、TNF-a, and it could be successfully fused with tumorcells in the presence of PEG, in addition, the DC-tumor fusion vaccinecan effectively induce specific killing of tumor cells by CTL cytotoxicactivity in vivo of experimental animals, and could trigger antitumorimmunity effect.