In vitro neutralization of IL-6 receptor exacerbates damage to intestinal epithelial cells during Mycobacterium avium paratuberculosis infection.

Autor:	Alhendi A; Division of Molecular Microbiology, Burnett School of Biomedical Sciences, College of Medicine. University of Central Florida, Orlando, FL, United States., Naser SA; Division of Molecular Microbiology, Burnett School of Biomedical Sciences, College of Medicine. University of Central Florida, Orlando, FL, United States.
Jazyk:	angličtina
Zdroj:	Frontiers in immunology [Front Immunol] 2024 Aug 07; Vol. 15, pp. 1412800. Date of Electronic Publication: 2024 Aug 07 (Print Publication: 2024).
DOI:	10.3389/fimmu.2024.1412800
Abstrakt:	Like TNFα, IL-6 is upregulated in Crohn's disease (CD) especially in patients associated with Mycobacterium avium paratuberculosis (MAP) infection, and both cytokines have been targeted as a therapeutic option for the treatment of the disease despite the accepted partial response in some patients. Limited response to anti-IL-6 receptor-neutralizing antibodies therapy may be related to the homeostatic dual role of IL-6. In this study, we investigated the effects and the signaling mechanism of IL-6 involved in intestinal epithelial integrity and function during MAP infection using an in vitro model that consists of THP-1, HT-29 and Caco-2 cell lines. Clinically, we determined that plasma samples from MAP-infected CD patients have higher IL-6 levels compared to controls (P-value < 0.001). In CD-like macrophages, MAP infection has significantly upregulated the secretion of IL-6 and the shedding of (IL-6R) from THP-1 macrophages, P-value < 0.05. Intestinal cell lines (Caco-2 and HT-29) were treated with the supernatant of MAP-infected THP-1 macrophages with or without a neutralizing anti-IL-6R antibody. Treating intestinal Caco-2 cells with supernatant of MAP-infected macrophages resulted in significant upregulation of intestinal damage markers including claudin-2 and SERPINE1/PAI-1. Interestingly, blocking IL-6 signaling exacerbated that damage and further increased the levels of the damage markers. In HT-29 cells, MAP infection upregulated MUC2 expression, a protective response that was reversed when IL-6R was neutralized. More importantly, blocking IL-6 signaling during MAP infection rescued damaged Caco-2 cells from MAP-induced apoptosis. The data clearly supports a protective role of IL-6 in intestinal epithelia integrity and function especially in CD patients associated with MAP infection. The findings may explain the ineffective response to anti-IL6 based therapy and strongly support a therapeutic option that restores the physiologic level of IL-6 in patient's plasma. A new treatment strategy based on attenuation of IL-6 expression and secretion in inflammatory diseases should be considered. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision. (Copyright © 2024 Alhendi and Naser.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu