Biology subjects

Corthay, A.

Publications and source records attributed to Corthay, A..

3 recordsLinked to original sources

bioRxiv2022

RNA-sensing pattern-recognition receptors synergize with TLR2 or dectin-1 to trigger high production of IL-12p70 by human dendritic cells

IL-12p70 is crucial for T helper 1 polarization and the generation of type 1 immunity that is required to fight cancer and intracellular pathogens. Therefore, strategies to optimize the production of IL-12p70 by dendritic cells (DCs) may significantly improve the efficacy of vaccines and immunotherapies for cancer. However, the rules governing the production of IL-12p70 remain obscure. Here, we stimulated pattern recognition receptors (PRRs) representing all five families of PRRs, to evaluate their ability to elicit high production of IL-12p70 by human DCs. We used ten well-characterized agonists and stimulated human monocyte-derived DCs in vitro with either single agonists or 26 different combinations. We found that poly(I:C), which engages the RNA-sensing PRRs TLR3 and/or MDA5, was the only agonist that could elicit IL-12p70 production when used alone. Combinations of agonists of cell surface and intracellular PRRs were found to synergize to induce high IL-12p70 production, given that the combination included poly(I:C) or resiquimod, which both are agonists of intracellular, RNA sensing PRRs (TLR3/MDA5 and TLR7/8, respectively). Our data show that production of high IL-12p70 is strictly controlled, which is different from what we observed for IFN{beta}, whose production could be elicited by several intracellular PRRs. In conclusion, we identified six different combinations of PRR ligands able to induce high IL-12p70 production by human DCs. The identified synergistic PRR ligand combinations may represent strong adjuvant candidates in particular for therapeutic cancer vaccines.

immunology↗

bioRxiv2020

Polysaccharides from the fungus Inonotus obliquus activate macrophages into a tumoricidal phenotype via interaction with TLR2, TLR4 and Dectin-1a

BackgroundTumor-associated macrophages (TAMs) may both promote and suppress tumor development. Therefore, molecules that are able to activate and repolarize these cells into a tumoricidal phenotype could be of great interest as a new strategy for cancer immunotherapy. Fungal {beta}-glucans have been suggested as a promising way of activating TAMs, but most of the research has been carried out on particulate {beta}-glucans of large sizes (> 500 kDa), which potentially have different biological properties than smaller, water-soluble molecules with similar structures. MethodsBone marrow-derived mouse macrophages were treated with 6 different purified polysaccharides isolated from the medicinal fungus Inonotus obliquus. Nitric oxide concentration was quantified using the Griess assay and by qPCR of iNOS mRNA. IL-6 and TNF- concentrations were quantified using Luminex ELISA technology (using human monocyte-derived macrophages and mouse bone-marrow derived macrophages). Growth inhibition of cancer cells was measured using radiolabeled thymidine. Receptor interaction was determined using HEK-Blue reporter cell lines and TLR4 KO macrophages. Main findingsThe acidic, water-soluble polysaccharides AcF1, AcF2 and AcF3 induced nitric oxide (NO) production by mouse macrophages when combined with IFN-{gamma}, leading to a strong subsequent tumoricidal activity by the macrophages. Tumoricidal activity of AcF1 and AcF3 was fully retained in TLR4 knockout macrophages, demonstrating that the macrophage activation was not dependent on TLR4. Further, AcF3 induced high levels of the pro-inflammatory cytokines IL-6 and TNF- in human and mouse macrophages, independent of co-activation with IFN-{gamma}. The polysaccharides were shown to bind TLR2, TLR4 and Dectin-1a to varying degrees, and these receptors were likely to be responsible for the macrophage activation. The acidic polysaccharides AcF1, AcF2 and AcF3 strongly activated TLR2, while AcF3 and AcF1 activated TLR4. The acidic polysaccharides had low affinity to Dectin-1a compared to the polysaccharides IWN, EWN and A1, which suggests that this receptor is not the main receptor for the pro-inflammatory activity observed. ConclusionFor the first time, this study demonstrates that I. obliquus polysaccharides are able to bind multiple pattern recognition receptors to activate macrophages into a pro-inflammatory anti-tumor phenotype. The induction of tumoricidal activity in the macrophages as well as the interaction with TLR2, TLR4 and Dectin-1a suggest that the I. obliquus polysaccharides may have unique ways of interacting with macrophages, which could open up for new treatment options in cancer immunotherapy.

immunology↗

bioRxiv2019

Tankyrase inhibition sensitizes melanoma to PD-1 immune checkpoint blockade in syngeneic mouse models

The development of immune checkpoint inhibitors represents a major breakthrough in cancer therapy. Nevertheless, a substantial number of patients fail to respond to checkpoint pathway blockade. {beta}-catenin is the key transcriptional regulator of WNT/{beta}-catenin signaling. Evidence for {beta}-catenin-mediated immune evasion is found in 13% of all cancers, 42% of primary cutaneous melanoma and a mouse melanoma model. Currently, there are no therapeutic strategies available for targeting WNT/{beta}-catenin signaling to counteract checkpoint inhibitor resistance in melanoma. Here we report that a specific small-molecule tankyrase inhibitor, G007-LK, attenuates WNT/{beta}-catenin and YAP signaling pathways in the syngeneic murine B16-F10 melanoma model enabling sensitivity to anti-PD-1 immune checkpoint therapy. RNA sequencing of 18 tankyrase inhibitor-treated human melanoma cell lines and B16-F10 cells revealed a transcriptional response profile for a subpopulation. This cell line sub-group displayed elevated baseline YAP signaling activity and was susceptible to reduce melanocyte inducing transcription factor (MITF) expression upon tankyrase inhibition.

cancer biology↗