Abstract 5140: Lipoxins and their role in Kaposi's sarcoma-associated herpesvirus (KSHV) infection and pathogenesis

Abstract

Abstract Lipoxins are host anti-inflammatory molecules, which play a vital role in restoring tissue homeostasis. The efficacy of lipoxins and their analog epilipoxins in treating inflammation and related diseases have been well documented. Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL) are two well-known inflammation-related diseases caused by Kaposi's sarcoma-associated herpesvirus (KSHV). Controlling inflammation is one of the strategies adopted to treat KS and PEL, a primary motivation for exploring and evaluating the therapeutic potential of using lipoxins. Our study demonstrates how KSHV manipulates and downregulates the secretion of the anti-inflammatory lipoxin A4 in host cells and the viral factors involved in this process using in vitro KS and PEL cells as models. Presence of lipoxin receptor [ALX/Formyl peptidyl receptor (FPR)] in human KS patient tissue sections and in vitro KS and PEL cell models offers a novel possibility for treating KS and PEL with lipoxins. Treating de novo KSHV-infected endothelial cells with lipoxin and epilipoxin creates an anti-inflammatory environment by decreasing levels of NFκB, AKT, ERK1/2, COX-2, and 5-lipoxygenase. Lipoxin treatment on CRISPR/CAS9 technology-mediated ALX/FPR gene-deleted U2OS cells revealed the importance of the lipoxin receptor ALX for effective lipoxin signaling. A viral miRNA cluster was identified as the primary factor contributing to the downregulation of lipoxin A4 secretion in host cells. The KSHV miRNA cluster probably targets enzyme 15-lipoxygenase, which is involved in lipoxin A4 synthesis. Lipoxin treatment in KSHV-infected cells has been shown to reduce cell proliferation and cell survival. Latency factor LANA-1 levels were found to decrease on lipoxin and epilipoxin treatment. Several pro-apoptotic gene levels were upregulated on lipoxin treatment. Several host transcription factors were found to play an important role in regulating KSHV life cycle. This study provides a new insight into the treatment of KS and PEL using nature's own anti-inflammatory molecule, lipoxin. Citation Format: Neelam Sharma-Walia, Jayashree A. Chandrasekharan. Lipoxins and their role in Kaposi's sarcoma-associated herpesvirus (KSHV) infection and pathogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5140.