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Review
, 20 (19)

Recent Advances in Our Understanding of the Link Between the Intestinal Microbiota and Systemic Lupus Erythematosus

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Review

Recent Advances in Our Understanding of the Link Between the Intestinal Microbiota and Systemic Lupus Erythematosus

Ji-Won Kim et al. Int J Mol Sci.

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease featuring enhanced expression of type I interferon (IFN) and autoantibody production triggering inflammation of, and damage to, multiple organs. Continuing research efforts focus on how gut microbes trigger systemic autoimmunity and SLE. The gut microbial communities of mice and humans with lupus have been investigated via high-throughput sequencing. The Firmicutes-to-Bacteroidetes ratio is consistently reduced in SLE patients, regardless of ethnicity. The relative abundance of Lactobacillus differs from the animal model used (MRL/lpr mice or NZB/W F1 mice). This may indicate that interactions between gut microbes and the host, rather than the enrichment of certain gut microbes, are especially significant in terms of SLE development. Enterococcus gallinarum and Lactobacillus reuteri, both of which are possible gut pathobionts, become translocated into systemic tissue if the gut epithelial barrier is impaired. The microbes then interact with the host immune systems, activating the type I IFN pathway and inducing autoantibody production. In addition, molecular mimicry may critically link the gut microbiome to SLE. Gut commensals of SLE patients share protein epitopes with the Ro60 autoantigen. Ruminococcus gnavus strain cross-reacted with native DNA, triggering an anti-double-stranded DNA antibody response. Expansion of R. gnavus in SLE patients paralleled an increase in disease activity and lupus nephritis. Such insights into the link between the gut microbiota and SLE enhance our understanding of SLE pathogenesis and will identify biomarkers predicting active disease.

Keywords: autoantibodies; host microbial interactions; interferon type I; microbiota; molecular mimicry; systemic lupus erythematosus.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Potential mechanisms by which the gut microbiota triggers the autoimmunity of systemic lupus erythematosus (SLE). SLE patients exhibit restricted gut microbial diversity, with the expansion of possible pathobionts. Impaired gut permeability (a “leaky gut”) allows translocation of pathobionts to mesenteric lymph nodes (MLNs) and the liver. E. gallinarum delivers ligands to the aryl hydrocarbon receptor (AhR), and activation of the AhR pathway induces proliferation of Th17 and Tfh cells; systemic autoantibody production follows. E. gallinarum induces type I interferon (IFN) expression by plasmacytoid dendritic cells (pDCs) and hepatocytes. Toll-like receptor 7 (TLR7)-dependent translocation of L. reuteri increases pDCs numbers and type I IFN expression, exacerbating SLE. Molecular mimicry of human autoantigens by bacterial orthologs triggers cross-reactive T and B cell responses, inducing autoimmunity. ↓, decreased.

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References

    1. Tsokos G.C., Lo M.S., Costa Reis P., Sullivan K.E. New insights into the immunopathogenesis of systemic lupus erythematosus. Nat. Rev. Rheumatol. 2016;12:716–730. doi: 10.1038/nrrheum.2016.186. - DOI - PubMed
    1. Barrat F.J., Meeker T., Gregorio J., Chan J.H., Uematsu S., Akira S., Chang B., Duramad O., Coffman R.L. Nucleic acids of mammalian origin can act as endogenous ligands for Toll-like receptors and may promote systemic lupus erythematosus. J. Exp. Med. 2005;202:1131–1139. doi: 10.1084/jem.20050914. - DOI - PMC - PubMed
    1. Lovgren T., Eloranta M.L., Bave U., Alm G.V., Ronnblom L. Induction of interferon-alpha production in plasmacytoid dendritic cells by immune complexes containing nucleic acid released by necrotic or late apoptotic cells and lupus IgG. Arthritis Rheum. 2004;50:1861–1872. doi: 10.1002/art.20254. - DOI - PubMed
    1. Jego G., Palucka A.K., Blanck J.P., Chalouni C., Pascual V., Banchereau J. Plasmacytoid dendritic cells induce plasma cell differentiation through type I interferon and interleukin 6. Immunity. 2003;19:225–234. doi: 10.1016/S1074-7613(03)00208-5. - DOI - PubMed
    1. Le Bon A., Schiavoni G., D’Agostino G., Gresser I., Belardelli F., Tough D.F. Type i interferons potently enhance humoral immunity and can promote isotype switching by stimulating dendritic cells in vivo. Immunity. 2001;14:461–470. doi: 10.1016/S1074-7613(01)00126-1. - DOI - PubMed

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