Inhibitory Effects Of Dendritic Cell (DC) Vaccine Loading Antigen With Apoptotic Tumor Cells Against Bladder Cancer Cells In Mice

Objective Dendritic cell is a function of the recursive antigen found most full-time antigen presenting cells, also can activate the immune response, the initial APC on immunization tumors plays an important role. The preparation and application of DC vaccines became immune therapy of cancer research hotspot.To investigate the effects of dendritic cell vaccine sensitized by antigen with irradiated apoptotic MB49 tumor cells on the treatment of bladder cancer in mice.Methods MB49 antigen was obtained by irradiation and then sensitized bone marrow derived DC (BM-DC) to establish DC vaccine.C57BL/6 mice bone marrow-derived DCs were cultured in RPMI-1640 with 10% FCS,10μg/L rmGM-CSF, 5μg/L rmIL-4 for 6 days and antigen with irradiated apoptotic MB49 tumor cells were added respectively to induce the maturation of DCs. Bone marrow cells were isolated from C57BL/6 mices’bone marrow and induced to differentiate to dendrtic cells(DCs) in vitro. Then DCs were stimulated mature using antigens with irradiated apoptotic MB49 tumor cells. Then the morphous and surface markers were detected. The expression levels of CD80 and CD86 on the surface of DC of tumor tissues collected from different group were detected by flow cytometry. Mice bearing bladder cancer were divided into DC group and control group. On the 7th and 14th day after subcutaneous injection of tumor cell, DC group was injected DC vaccine, and the control group was injected PBS. Each group was divided into two subgroups in order to measure tumor mass and volume and to observe survival conditition of mice.Results Results of identification showed that the cultured cells were morphology-and phenotype-typical DCs. With dendritic cell (DC) vaccine cultured for 5 days, by detecting surface antibody shows high expression of CD11c, but low expression of CD80, CD86 and I-A, they were suggesting immature DCs.LPS or tumor antigen was added and co-culture, at seventh day, by detecting CD80, CD86 and I-A they were suggesting maturation DCs. After co-cultured for one day with immature DC and apoptotic tumor cells FCM tests showed that immature DC grew into mature DC.After X-ray irradiation, tumor cell apoptosis cells reached optimum number at the third day.The average mass and volume of tumors in mice of DC group were significantly higher than those of the control group(P<0.01),which also had longer survival preoid. Two mice in DC group survived without tumor for 30 days.Although they were injected MB49 cells for the second time, there was no tumor growth in 30 days.Conclusions DCs are the most powerful professional antigen presentirag cells. DC vaccines loading antigen with irradiated apoptotic MB49 tumor cells can inhibit the growth of MB49 cell in vivo. DC vaccine can induce effector cells to appear strong cytotoxicity and killing activity on bladder tumor cell MB49.DC vaccine plused with tumor antigen can lead to complete rejection of tumor rechallenge,which shows that this method should be an appealing immunotherapeutic approach to preventing the recurrence of bladder tumor in clinic.lt also indicates that anti-tumor biological therapy that circles DCs is expected to improve the overall therapeutic level of bladder tumor.