AB47. The research of cytotoxicity of EpCAM antigen-specific immune effectors to EpCAMhigh adenocarcinoma cells in vitro
Abstract

AB47. The research of cytotoxicity of EpCAM antigen-specific immune effectors to EpCAMhigh adenocarcinoma cells in vitro

Ye Zhou1,2, Shujiao Zhang1,2, Fei Gao1,2, Jianhui Cai1,2

1Teaching & Research Section, Hebei Medical University, Shijiazhuang 050017, China; 2Department of Surgery, Department of Oncology & Immunotherapy, Hebei General Hospital, Shijiazhuang 050051, China

Background: Epithelial cell adhesion molecule (EpCAM) is overexpressed abnormally in nearly all adenocarcinomas including colon cancer, gastric cancer, breast cancer and so on. The highest expression levels of EpCAM on gastrointestinal adenocarcinomas are more than 95%. EpCAM is closely related to the proliferation of cancer cells and the prognosis of the tumor. In recent years, EpCAM has been regarded as the new target of immunotherapy of tumor. Culturing EpCAM specific effectors is used to generate new effectors that with better specific killing effective.

Objective: To explore the killing efficiency of EpCAM antigen-specific immune effector cells cultured in vitro. Compare the killing rates between EpCAM antigen-specific immune effectors and full antigens of EpCAMhigh adenocarcinoma cells-specific immune effectors.

Methods: Collected mononuclear cells (PBMCs) from peripheral blood of healthy adults. Induction of T lymphocytes into CIK cells and amplification of CIK cells in vitro. imDCs pushed with purified EpCAM polypeptide antigen to generated EpCAM antigen mature DCs that named Ep-mDCs. Ep-mDCs and autologous CIK cells were co-cultured in vitro, part of CIK cells turn to EpCAM antigen-specific cytotoxic CTL after EpCAM antigens information were presented by Ep-mDCs, and then EpCAM antigen-specific DC-CIK-CTL effector cells (Ep-effector) were generated. EpCAMhigh LS174-T colon adenocarcinoma cells and EpCAMlow PaCa-2 pancreatic cells were selected to be target cells. Detected the killing rates of each group of effector cells to EpCAMhigh LS174-T and EpCAMlow PaCa-2 at different E:T by Cytotoxicity assay (CCK-8 method), and analyzed the statistical differences.

Results: The expressions of surface molecules in LS-mDCs and Ep-mDCs have no significant difference. With the target ratio (E:T) increased, the killing rates of effector cells in each group were all raised. The killing rates to LS174-T cells in Ep-effector group were higher than the others, but have no difference between CIK group and Ls-effector group. The killing rates to PaCa-2 have no difference between each other group.

Conclusions: This is the first time that we use EpCAM antigen to push imDCs to generate Ep-mDCs. And the function that Ep-mDCs can active T cells to generate CTLs had been provided. Ep-effector has a higher specific cytotoxicity for EpCAMhigh adenocacinoma cells.

Cite this abstract as: Zhou Y, Zhang S, Gao F, Cai J. The research of cytotoxicity of EpCAM antigen-specific immune effectors to EpCAMhigh adenocarcinoma cells in vitro. Transl Gastrointest Cancer 2015;4(S1):AB47. doi: 10.3978/j.issn.2224-4778.2015.s047