The Preliminary Study On The Inhibition Effect Of Tumor Lysate-pulsed Dendritic Cells To Murine Breast Carcinoma

Objective: murine bone marrow-generated dendritic cells (DCs) are cultured in vitro and pulsed with EMT6 tumor lysates. The research is designed to investigate whether those tumor antigen pulsed DCs can induce immunity against murine EMT6 breast cancer in vivo, and find out the optimal injection sites, frequency and how to use immune adjuvant to achieve the most satisfying results.Methods: Bone marrow cells were removed from femurs and tibias of Balb/Cmice, depleted of erythrocytes and cultured in vitro to generate DCs. After pulsed with EMT6 tumor lysates, murine DCs are analysed with flow cytometer (FCM) . Experiment I Five groups of mice are transplanted EMT6 cell lines to establish tumor model , and then are subcutaneously injected with saline , tumor lysates, immature DCs and mature DCs i. e. The last group is injected with mature DCs at multiple sites and more frequency. Experiment II We also apply a kind of immune adjuvant named BA, which is synthesized from pseudomonas aeruginosa. Four groups of mice with EMT6 tumor are injected with saline, BA, mature DCs and mature DCs coupled with BA.Results: multiple sites injection of tumor lysates pulsed DCs can inhibit the growth of murine breast carcinoma significantly compared with control group(P=0. 004), while the difference of tumor volume between the control group and the single site injection ofmature DCs is not statistically significant (P=0. 12) . Single use of BA has not been observed to inhibit carcinoma significantly compared with control (P=0. 06); but tumor lysates pulsed DCs coupled with BA is shown to reduce the murine tumor volume significantly compared with the control group (P =0. 014) and pure DCs group (P =0. 047) .Conclusions: the experiments illustrate that tumor lysates pulsed DCs can induce an effective anti-tumor immune response in vivo, and the anti-tumor immunity can be strengthened when we increase properly the sites and frequency of DC injection. DCs coupled with immune adjuvant BA could even further improve its anti-tumor immunity. The results collectively provide a basis for our further clinical research on how to optimize DC tumor vaccine.