Patient-derived dendritic cells transduced with an α-fetoprotein-encoding adenovirus and co-cultured with autologous cytokine-induced lymphocytes induce a specific and strong immune response against hepatocellular carcinoma cells

Background/Aims: Breaking immunologic tolerance towards the hepatocellular carcinoma (HCC)-associated alpha-fetoprotein (AFP) antigen is possible. The use of this potential for the treatment of immunocompromised HCC patients is limited. In this study, we analyzed whether dendritic cells (DCs) from HCC patients transduced with a human AFP (hAFP)-expressing adenovirus and co-cultured with cytokine-induced killer (CIK) cells can induce a strong specific immune response against HCC-cells. Methods: An hAFP-encoding adenovirus (Ad-hAFP) was generated. DCs from healthy donors or patients were transduced at a very high efficacy. Afterwards, DCs were co-cultured with autologous CIK-cells, and their ability to lyse HCC-cells was analyzed. Results: AFP-transduced DCs stimulated CIK cells strongly to lyse about 70% of AFP-expressing HCC cells. Cytotoxicity was significantly higher when lymphocytes were co-cultured with Ad-hAFP-transduced DCs than with Ad-mock-transduced DCs, indicating an AFP-specific immune response. More interestingly, CIK cells from patients with AFP-positive HCC could be stimulated to lyse AFP-expressing HCC cells as effectively as CIK cells from healthy individuals and stronger than CIK cells from patients without AFP-expressing HCC. Conclusions: The data demonstrate that patient-derived DCs that were transduced with an AFP-expressing adenovirus and co-cultured with autologous CIK cells induce an AFP-specific, strong immune response against HCC cells. Therefore, this approach may have a potential for an adoptive and/or DC-based immunotherapy for HCC patients.