Recombinant Heat Shock Protein 70 in Combination with Radiotherapy as a Source of Tumor Antigens to Improve Dendritic Cell Immunotherapy

• Main Authors: Yu-Shan eWang, Shih-Jen eLiu, Su-Chen eHuang, Chao-Chun eChang, Yi-Chun eHuang, Weng-Lam eFong, Mau-Shin eChi, Kwan-Hwa eChi
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2012-10-01
• Series: Frontiers in Oncology
• Subjects: Dendritic Cells; Immunotherapy; Radiotherapy; Tumor Microenvironment; heat shock protein 70
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fonc.2012.00149/full

Local radiotherapy (RT) plus intratumoral dendritic cell (DC) injection can mediate immunological response. We hypothesized that co-injection of exogenous recombinant heat shock protein 70 (rHsp70) in combination with RT-DC could be as effective as co-injection of HSP-peptide for evoking specific immune response. rHsp70-prostate-specific antigen (rHSP70C'-PSA) and alpha-fetoprotein (rHSP70C'-AFP) were used to compare specific response. Growth inhibition of the tumor and the systemic anti-tumor immune response were measured on CT26/PSA and CT26/AFP mice model. Intratumoral co-injection of rHsp70 and DC into the irradiated tumor site induced a more potent anti-tumor immune response than injection of DC alone. rHsp70 was as effective as rHsp70C'-PSA or rHsp70C'-AFP in inducing a tumor-specific cytotoxic T lymphocyte response or tumor growth delay. These results demonstrate that co-administration with rHsp70 and radiotherapy could be a simple and effective source of tumor antigens to achieve RT-DC immunotherapy protocol and easy to apply in clinical use.