Topographical and Biological Evidence Revealed FTY720-Mediated Anergy-Polarization of Mouse Bone Marrow-Derived Dendritic Cells In Vitro

Xiangfeng Zeng,Tong Wang,Yaoying Zeng,Yanxia Ye,Xiaobo Xing,Cairong Zhu,Bing Song,Xinqiang Lai,Martin Stangel

doi:10.1371/journal.pone.0034830

Xiangfeng Zeng, Tong Wang + Show 7 more

Open Access

https://doi.org/10.1371/journal.pone.0034830

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Journal: PLoS ONE	Publication Date: May 31, 2012
Citations: 57	License type: CC BY 4.0

Affiliation: Jinan University

Abstract

Abnormal inflammations are central therapeutic targets in numerous infectious and autoimmune diseases. Dendritic cells (DCs) are involved in these inflammations, serving as both antigen presenters and proinflammatory cytokine providers. As an immuno-suppressor applied to the therapies of multiple sclerosis and allograft transplantation, fingolimod (FTY720) was shown to affect DC migration and its crosstalk with T cells. We posit FTY720 can induce an anergy-polarized phenotype switch on DCs in vitro, especially upon endotoxic activation. A lipopolysaccharide (LPS)-induced mouse bone marrow-derived dendritic cell (BMDC) activation model was employed to test FTY720-induced phenotypic changes on immature and mature DCs. Specifically, methods for morphology, nanostructure, cytokine production, phagocytosis, endocytosis and specific antigen presentation studies were used. FTY720 induced significant alterations of surface markers, as well as decline of shape indices, cell volume, surface roughness in LPS-activated mature BMDCs. These phenotypic, morphological and topographical changes were accompanied by FTY720-mediated down-regulation of proinflammatory cytokines, including IL-6, TNF-α, IL-12 and MCP-1. Together with suppressed nitric oxide (NO) production and CCR7 transcription in FTY720-treated BMDCs with or without LPS activation, an inhibitory mechanism of NO and cytokine reciprocal activation was suggested. This implication was supported by the impaired phagocytotic, endocytotic and specific antigen presentation abilities observed in the FTY720-treated BMDCs. In conclusion, we demonstrated FTY720 can induce anergy-polarization in both immature and LPS-activated mature BMDCs. A possible mechanism is FTY720-mediated reciprocal suppression on the intrinsic activation pathway and cytokine production with endpoint exhibitions on phagocytosis, endocytosis, antigen presentation as well as cellular morphology and topography.

Highlights

Dendritic cells (DCs) represent a typical cell type participating in the ‘‘dual-edge sword’’ in immunity
After being co-treated by granulocyte macrophage colonystimulating factor (GM-CSF) and IL-4, mouse bone marrow cells were differentiated into bone marrowderived dendritic cell (BMDC), showing (95.961.7)% positive for the macrophage/DC lineage marker CD11c (Figure 1A)
The overall results of this study suggested FTY720 induces an anergy-polarized effect on BMDCs, exhibiting molecular, topographical, morphological and functional changes

Summary

Introduction

Dendritic cells (DCs) represent a typical cell type participating in the ‘‘dual-edge sword’’ in immunity. Chronic lesion formation in atherosclerosis was found to be etiologically relevant to DC-induced proinflammatory cytokine production, especially in terms of synergistically inflammatory attacks on the vascular walls caused by hypercholesterolemia in blood and microbial antigens on endothelial cells [1,2,3,4]. This is comparable with more specific findings in acute bacterial infections [5,6]. This mechanism was found pivotal in sepsis survivors as a negative-feedback mechanism to prevent acute endotoxic shock [5,6]

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