Jeong, Youngmin Kim, Gi Beom Ji, Yuhyun Kwak, Gi-Jung Nam, Gi-Hoon Hong, Yeonsun Kim, Seohyun An, Jinsu Kim, Sun Hwa Yang, Yoosoo Chung, Hak Suk Kim, In-San 2024-01-19T18:02:46Z 2024-01-19T18:02:46Z 2021-09-05 2020-03 0304-3835 https://pubs.kist.re.kr/handle/201004/118917 Cancer immunotherapy is a powerful approach for cancer treatment, but its clinical effects rely on the tumor's immune conditions. In particular, low response rates to PD-1 blockades are highly correlated with impaired T cell priming. Here, we demonstrate that E. coli-derived monophosphoryl lipid A (EcML) activates dendritic cells in a toll-like receptor-4 (TLR-4)-dependent manner and increases the sensitivity of cancer cells to anti-PD-1 immunotherapy. EcML is a mixture of 4'-monophosphoryl lipids A (MPLAs) produced directly by an engineered Escherichia coli strain; it has a unique congener composition that differentiates it from the well-established MPLA adjuvants, 3-O-desacyl-4'-monophosphoryl lipid A and glucopyranosyl lipid A. Given that active dendritic cells initiate adaptive immune responses, we investigated the anti-tumor activity of an aqueous formulation of EcML. Upon sensing EcML via TLR-4, dendritic cells matured into powerful antigen-presenting cells that could stimulate naive T cells. EcML reduced tumor growth in the B16F10 mouse model via dendritic cell activation and potentiated PD-1 blockade therapy in the B16F10-OVA melanoma model. These data identify EcML as a promising TLR-4 agonist that can induce anti-tumor immune responses and potentiate PD-1 blockade therapy against tumors. English ELSEVIER IRELAND LTD Dendritic cell activation by an E. coli-derived monophosphoryl lipid A enhances the efficacy of PD-1 blockade Article 10.1016/j.canlet.2019.12.012 1 CANCER LETTERS, v.472, pp.19 - 28 CANCER LETTERS 472 19 28 N scie scopus 000509612300003 2-s2.0-85076694553 Oncology Oncology Article TLR4 AGONIST IFN-GAMMA RESISTANCE RESPONSES ANTIGEN TRIF TLR-4 agonist Antigen presenting cell E.coli-derived monophosphoryl lipid A Immuno-adjuvant Immune checkpoint blockade