Antitumor immunopreventive and immunotherapeutic effect in mice induced by hybrid vaccine of dendritic cells and hepatocarcinoma in vivo.

Aim: To develop atumor vaccine by fusion of H22 hepatocarcinoma cells and DC, and to study its protective and therapeutical effect against H22 cell.
Methods: H22-DC vaccine was produced by PEG fusion of H22 and DC induced by cytokine released from splenic mononuclear cells, sorted by CD11c magnetic microbead marker. It was injected through the tail vein of the mice and the H(22)-DC oncogenesis was detected in the liver, spleen and lung. In order to study the therapeutical and protective effect of H(22)-DC against tumor H(22), two groups were divided: immune group and therapeutic group. Immune group was further divided into P, D, HD and H subgroups, immunized by PBS, DC, H(22)-DC and inactivated H(22), respectively, and attacked by H(22) cell. The tumor size, tumor weight, mice survival time and tumor latent period were recorded and statistically analyzed; Therapeutical group was divided into three subgroups of P, D and HD, and attacked by H(22), then treated with PBS, DC, and H(22)-DC, respectively. Pathology and flow cytometry were also applied to study the mechanism how the H(22)-DC vaccine attacked on the H(22) cell.
Results: 1. No oncogenesis was found in spleen, lung and liver after H22-DC injection. 2. Hybrid vaccine immunized mice had strongest CTL activity. 3. In the immune group, latent period was longer in HD subgroup than that in P, H and D subgroup; and tumor size and weight were smaller in HD subgroup than that in P, H and D subgroup. 4. In therapeutic group, tumor size was smaller in HD subgroup than that in P, D subgroup.
Conclusion: 1. H22-DC tumor vaccine is safe without oncogenesis in vivo. 2. Hybrid vaccine can stimulate potent specific CTL activity against H22. 3. H22-DC vaccine has distinctive prophylatic effect on tumor H22 and can inhibit the tumor growth.