PD47-07 A GENETICALLY MODIFIED BCG THAT OVEREXPRESSES A STING AGONIST SHOWS ENHANCED ANTITUMOR EFFICACY MEDIATED BY AN M1 MACROPHAGE POLARIZATION WITH POTENTIATION OF TRAINED IMMUNITY

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology IV (PD47)1 Apr 2020PD47-07 A GENETICALLY MODIFIED BCG THAT OVEREXPRESSES A STING AGONIST SHOWS ENHANCED ANTITUMOR EFFICACY MEDIATED BY AN M1 MACROPHAGE POLARIZATION WITH POTENTIATION OF TRAINED IMMUNITY Alok Singh*, Monali Praharaj, Kara Lombardo, Andres Matoso, Gregory Joice, Takahiro Yoshida, Max Kates, David McConkey, William Bishai, and Trinity J. Bivalacqua Alok Singh*Alok Singh* More articles by this author , Monali PraharajMonali Praharaj More articles by this author , Kara LombardoKara Lombardo More articles by this author , Andres MatosoAndres Matoso More articles by this author , Gregory JoiceGregory Joice More articles by this author , Takahiro YoshidaTakahiro Yoshida More articles by this author , Max KatesMax Kates More articles by this author , David McConkeyDavid McConkey More articles by this author , William BishaiWilliam Bishai More articles by this author , and Trinity J. BivalacquaTrinity J. Bivalacqua More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000934.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Trained immunity (TI) involving metabolic and epigenetic reprogramming of monocytes/macrophages confers a heightened immune status, and BCG has been shown to be a potent inducer of TI. We hypothesized that a genetically engineered BCG overexpressing a STING agonist may be a stronger inducer of antitumor TI. Using a recombinant BCG strain (BCG-disA-OE) which releases high levels of the STING agonist c-di-AMP, we tested induction of TI phenotypes in NMIBC models in vitro and in vivo. METHODS: WT-BCG (Tice strain) and BCG-disA-OE were compared for their induction of cytokines and phagocytic capacity in primary human and murine macrophages using ELISA, flow-cytometry, and immunofluorescence. We also measured epigenetic changes in the promoter regions of key cytokines using ChIP-PCR in human PBMC-derived monocytes. Antitumor efficacy was tested in the rat MNU-carcinogen model of NMIBC following intravesical BCG instillation weekly x 6 using histochemical tumor grading and qRT-PCR of bladder tissue. RESULTS: Compared with BCG-WT, BCG-disA-OE strains showed increased IFN I, IL-6, TNF-α, MCP-1 and IL-12 levels in primary macrophages and bladder cancer cell lines We observed increased M1 polarization shift and higher phagocytic capacity in primary macrophages after infection with rBCG-disA-OE. The modified BCG also elicited more pronounced epigenetic changes (H3K4Me3) on the TNF-α and IL-6 gene promoters following monocyte training. Intravesical instillations of BCG-disA-OE in MNU-rats resulted into significantly lower tumor involvement index and a more a potent induction of Th1 cytokines compared to BCG-WT. CONCLUSIONS: BCG-disA-OE demonstrated superior antitumor efficacy in the rat NMIBC model. It also elicited greater levels of pro-inflammatory cytokine secretion, M1 macrophage polarization, and epigenetic reprogramming. These observations suggest that BCG-disA-OE elicits more potent trained immunity changes monocytic cell populations in the bladder, and that elevated trained immunity may correlate with treatment outcome. BCG-disA-OE shows promise as a novel intravesical immunotherapy for NMIBC. Source of Funding: Maryland Tedco, Willowcroft Foundation, and Cigarette Restitution Fund © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e928-e928 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alok Singh* More articles by this author Monali Praharaj More articles by this author Kara Lombardo More articles by this author Andres Matoso More articles by this author Gregory Joice More articles by this author Takahiro Yoshida More articles by this author Max Kates More articles by this author David McConkey More articles by this author William Bishai More articles by this author Trinity J. Bivalacqua More articles by this author Expand All Advertisement PDF downloadLoading ...