Abstract: Polyinosinic-polycytidylic acid is a synthetic analog of double-stranded RNA, which plays a vital role in the regulation of immune system. Toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MAD-5) and retinoic acid inducible gene -Ⅰ (RIG-Ⅰ) are the main three intracellular receptors binding to polyinosinic-polycytidylic acid which activates human anti-tumor immune responses including the activation of innate immunity and acquired immunity through TIR-domain-containing adapter-inducing interferon-β (TRIF) and interferon-β. Thus, polyinosinic-polycytidylic acid plays an important role in regulating anti-tumor immune responses. The immunoregulation mechanisms of polyinosinic-polycytidylic acid in melanoma, breast cancer, malignant glioma and lung cancer have been clarified, which will provide new strategies for tumor immunotherapy.

Key words: color: black, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-bidi-font-family: 'Times New Roman', mso-fareast-font-family: 宋体">Poly I-C, color: black, font-family: "Times New Roman", mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体">Immunity, color: black">Neoplasms