Targeting Toll-Like Receptor 9 with CpG Oligodeoxynucleotides Enhances Anti-Tumor Responses of Peripheral Blood Mononuclear Cells from Human Lung Cancer Patients

• Published in: Cancer investigation 2008-06, Vol.26 (5), p.448-455
• Main Authors: Ren, Tao, Wen, Zhen-Ke, Liu, Zhong-Min, Qian, Cheng, Liang, Yong-Jie, Jin, Mei-Ling, Cai, Ying-Yun, Xu, Lin
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - pharmacology; Animals; Antineoplastic Agents - pharmacology; CD8-Positive T-Lymphocytes - drug effects; CD8-Positive T-Lymphocytes - immunology; Cell Proliferation - drug effects; Cells, Cultured; Chloroquine - pharmacology; CpG Oligodeoxynucleotides; Cytotoxicity, Immunologic - drug effects; Dose-Response Relationship, Drug; Humans; Immunotherapy - methods; Immunotherapy, Adoptive; Interferon-alpha - metabolism; Interleukin-12 - metabolism; Leukocytes, Mononuclear - drug effects; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - transplantation; Lung cancer; Lung Neoplasms - immunology; Lung Neoplasms - therapy; Mice; Mice, Inbred BALB C; Mice, Nude; Oligodeoxyribonucleotides - pharmacology; PBMCs; Time Factors; TLR9; Toll-Like Receptor 9 - metabolism; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 0735-7907; 1532-4192
• DOI: 10.1080/07357900701681608

CpG-oligonucleotides (CpG-ODN), which induce signaling through Toll-like receptor 9 (TLR9), are currently under investigation as adjuvants in therapy against infections and cancer. However, whether the CpG-ODN alone could enhance the anti-tumor immunity and the underlying mechanisms remains unclear. Here, we investigated that stimulation of peripheral blood mononuclear cells (PBMCs) from human lung cancer patients with CpG-ODN induced proliferation responses of the PBMCs, accompanied by the elevated cytokine secretion, including IFN-α, IL-12 and TNF-α. In addition, after treatment with CpG-ODN, the cytotoxic activity of the PBMCs and the production of IFN-γ in CD8+ T cells were dramatically enhanced. Furthermore, we found that adoptive transfer of CpG-ODN treated PBMCs significantly inhibited the tumor progression in nude mice, which were challenged with the autologuous tumor cells from human lung cancer patients. Finally, we demonstrated that the inhibitory CpG ODN or chloroquine could dramatically abrogate the enhanced anti-tumor responses of the CpG ODN treated PBMCs. Our findings suggest that the CpG-ODN is promising as a preventive and therapeutic anti-tumor measure against pulmonary carcinoma.