[Immunotherapy against tumor with dendritic cell sensitized by necrotic tumor tissue after microwave coagulation
1Department of Interventional Therapy, Peking University, School of Oncology, Peking Cancer Hospital, Beijing 100036, China.
Objective:
To evaluate if the necrotic tumor tissue treated with microwave coagulation therapy (MCT) can sensitize dendritic cell (DCs), and if the sensitized DCs have the specific inhibit effect on tumor cell.
Methods:
CT-26 tumor nodules planted percutaneously in BALB/c mice were treated with MCT. The treated tumor tissue was levigated and filtrates and the filtrate obtained was incubated with the DCs from marrow of the BALB/c mice to get sensitized DCs. The shape of the DCs was observed by the microscopy and the electron microscopy respectively and the immune phenotype was detected by flow cytometer. The ability of the DCs to induce proliferation of T cells was measured by (3)H-TdR incorporation assay. The cytotoxicity of CTL activated by the DCs was measured by (51)Cr release assay. The inhibition of the DCs on the growth of CT-26 tumor in the mice was observed.
Results:
The DCs cultured with the filter from necrotic tissue of CT-26 tumor had the typical shape and immune phenotype of the sensitized DCs. The intensity of the sensitized DCs and the naive DC to stimulate T lymphocyte proliferation at the DC/T of 1:10 was 80 +/- 10 vs 10 +/- 5 (P < 0.01); and at the DC/T of 1:20 was 58 +/- 7 vs 9 +/- 3 (P < 0.01). The killing effect of specific CTLs on CT-26 cancer cells in the sensitized DCs and the naive DCs group were 13.6 +/- 2.5 vs 1.1 +/- 0.4 (P < 0.01) at the E/T of 10:1, 27.5 +/- 4.4 vs 1.4 +/- 0.4 (P < 0.01) at E/T 20:1, and 51.2 +/- 8.1 vs 1.4 +/- 0.5 (P < 0.01) at the E/T of 50:1 respectively. The specific CTL's killing effect on MIP/ND4 lymphoma cells in the sensitized DCs and the naive DCs group were 2.61 +/- 0.64 vs 0.87 +/- 0.15 (P > 0.01) at the E/T of 10:1, 5.22 +/- 0.65 vs 2.18 +/- 0.41 (P > 0.01)at the E/T of 20:1, and 6.09 +/- 0.83 vs 3.91 +/- 0.51 (P > 0.01) at the E/T of 50:1 respectively. The difference of the volumes of the tumor implanted percutaneously in the BALB/c mice became more and more obviously with the prolongation of mice survival times in the sensitized DC group, the naive DC group and the control group. The weight of the tumor at the fortieth day were 4.5 g +/- 1.1 g, 6.9 g +/- 1.6 g, 9.0 g +/- 1.5 g in the three groups respectively (P < 0.01). Finally the special killing effect of the T cells which extracted from the spleen of the mice whose tumor had been treated by the sensitized DCs in vivo and in vitro were observed.
Conclusion:
As an whole cell antigen, the necrotic CT-26 tumor tissue treated with MCT can sensitize DCs, and the sensitized DCs have the specific inhibitory effect on CT-26 tumor cells both in vivo and in vitro.
