Involvement of Toll-Like Receptor 4 Signaling in Interferon-γ Production and Antitumor Effect by Streptococcal Agent OK-432

• Published in: JNCI : Journal of the National Cancer Institute Vol. 95; no. 4; pp. 316 - 326
• Main Authors: Okamoto, Masato, Oshikawa, Tetsuya, Tano, Tomoyuki, Ohe, Go, Furuichi, Sachiko, Nishikawa, Hidetomo, Ahmed, Sharif Uddin, Akashi, Sachiko, Miyake, Kensuke, Takeuchi, Osamu, Akira, Shizuo, Moriya, Yoichiro, Matsubara, Shuzo, Ryoma, Yoshiki, Saito, Motoo, Sato, Mitsunobu
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 19.02.2003
• Subjects: Aged; Animals; Anti-Bacterial Agents - pharmacology; Antigens, Surface - genetics; Antigens, Surface - metabolism; Antineoplastic agents; Antineoplastic Agents - pharmacology; Biological and medical sciences; Drosophila Proteins; Enzyme-Linked Immunosorbent Assay; Female; Head and Neck Neoplasms - chemistry; Head and Neck Neoplasms - drug therapy; Head and Neck Neoplasms - immunology; Humans; Immunotherapy; Injections, Intraperitoneal; Interferon-gamma - biosynthesis; Interferon-gamma - blood; Interferon-gamma - drug effects; Luciferases - analysis; Lymphocyte Antigen 96; Male; Medical sciences; Membrane Glycoproteins - deficiency; Membrane Glycoproteins - drug effects; Membrane Glycoproteins - immunology; Membrane Glycoproteins - metabolism; Mice; Mice, Inbred C57BL; Middle Aged; Pharmacology. Drug treatments; Picibanil - pharmacology; Polymyxin B - pharmacology; Receptors, Cell Surface - deficiency; Receptors, Cell Surface - drug effects; Receptors, Cell Surface - immunology; Receptors, Cell Surface - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; RNA, Neoplasm - analysis; Signal Transduction - drug effects; Toll-Like Receptor 4; Toll-Like Receptors; Antineoplastic agent; Lewis lung carcinoma; Carcinoma; Spontaneous; Biosynthesis; Bronchopulmonary; Signal transduction; Immunotherapy; Head and neck; Bacteria; Micrococcales; ENT disease; Streptococcus pyogenes; Biological receptor; Human; Lung disease; Respiratory disease; Cytokine; Rodentia; Malignant tumor; In vitro; Streptococcaceae; In vivo; Vertebrata; Mammalia; Treatment; Microbial origin; Mouse; Animal; Gamma interferon
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/95.4.316

Background: The streptococcal agent OK-432 has been used for immunotherapy of head and neck cancer, among other malignancies, but its mechanism of action is unknown. Because the Toll-like receptor 4 (TLR4)/MD-2 complex is important in enabling the mammalian immune system to recognize bacterial components, we investigated whether expression of the TLR4 and MD-2 genes is associated with OK-432-induced anticancer immunity. Methods: Peripheral blood mononuclear cells (PBMCs) from 28 patients with head and neck cancer were analyzed for TLR4 and MD-2 mRNA expression by reverse transcription–polymerase chain reaction (RT–PCR) analysis. PBMCs were treated in vitro with OK-432 or with OK-PSA (a lipoteichoic-acid-related molecule that is an active component of OK-432), and interferon-gamma (IFN-γ) mRNA expression, an immune response measure, was analyzed by RT–PCR. Patient sera collected 24 hours after OK-432 administration were examined for IFN-γ protein using an enzyme-linked immunosorbent assay. Lewis lung carcinoma-bearing wild-type C57BL/6 and TLR4-deficient mice (four mice per group) received intraperitoneal injections of OK-432, and tumor volumes and sera IFN-γ levels were measured over time. All statistical tests were two-sided. Results: Twenty patients expressed both TLR4 and MD-2. Expression of TLR4 and MD-2 genes was associated with the in vivo IFN-γ induction in 19 patients administered OK-432 (Fisher's exact test P<.001). Although both OK-432 and OK-PSA induced IFN-γ expression from PBMCs in vitro, expression of TLR4 and MD-2 was associated only with IFN-γ expression induced by OK-PSA (P<.001). In vivo intraperitoneal administration of OK-432 resulted in an increase of IFN-γ in sera from wild-type mice but not in sera from TLR4-deficient mice. Tumors in wild-type mice treated with OK-432 were statistically significantly smaller than those in mice treated with saline (P = .007). By contrast, in TLR4-deficient mice, there was no difference in tumor volume between the two treatment groups. Conclusions: TLR4 and MD-2 may mediate OK-432-induced anticancer immunity.