Specific antitumor immune response induced by infusion of Capan-2 pancreatic cancer cells and dendritic cells: an in vitro study

Objective To investigate the specific antitumor immune response induced by the infusion of Capan- 2 pancreatic cancer cells and dendritic cells( DC). Methods DC were isolated from the peripheral blood mononuclear cells( PBMC) derived from 6 patients with pancreatic cancer and cultured. The DC obtained were divided into three groups. In group 1,PEG- DMSO was used for induction,and DC and Capan- 2 cells were fused to bear tumor antigens. In group 2,DC were cultured with Capan- 2 cells. In group 3,DC were cultured alone. Flow cytometry was used to detect PE- MUC4 / FITC- CD86 double- labeled cells and assess the fusion rate,and MTT assay was used to determine the changes in viability of DCs in each group. IFNγ enzyme- linked immunosorbent assay was used to detect the activation reactions of cytotoxic T lymphocytes( CTLs) induced by DCs. The 51 Cr standard cytotoxicity test was used to determine the killing effect of antigen- specific CTLs induced by DCs on in vitro pancreatic cancer cells. An analysis of variance was used for comparison between multiple groups. The LSD- t test was used for comparision between any two groups. Results The DC- Capan- 2 fused cells expressed DC phenotype( CD86) and MUC4 molecules and had a significantly higher double- positive rate for CD86 and MUC4 than the co- cultured group( 38. 30% ±7. 30% vs 7. 21% ± 1. 06%). In the fusion group,the viability of DCs decreased in a time- dependent manner and reached62. 81% at 96 hours after transfection,while in the co- cultured group,the viability of DCs was maintained above 80%. The viability of DC showed a significant difference between these two groups( P < 0. 05). The release of IFNγ showed a significant difference between CTLs induced by DC- Capan- 2 fused cells and those induced by DCs in the co- cultured group( 85. 34 ± 2. 97 U / ml vs 19. 07 ± 4. 25 U / ml,P<0. 05). The specific CTLs induced by DC- Capan- 2 fused cells could effectively identify identified and killed the HLA- A2~+/ MUC4~+Capan- 2 cells and the HLA- A2~+/ MUC4-PANC- 1 cells,but did not effectively identify and kill the HLA- A2-/ MUC4-Mia Pa Ca- 2 cells and the HLA- A2-/ MUC4~+As PC- 1 cells. Conclusion The fusion of pancreatic cells and DCs can induce a pronounced CTL anti- tumor immune response in CTLs,which is limited by which was restricted by MHC class I antigen presentedpresentation.