Journal of autoimmunity
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Journal of autoimmunity · Aug 2018
ReviewConnecting the immune system, systemic chronic inflammation and the gut microbiome: The role of sex.
Unresolved low grade systemic inflammation represents the underlying pathological mechanism driving immune and metabolic pathways involved in autoimmune diseases (AID). Mechanistic studies in animal models of AID and observational studies in patients have found alterations in gut microbiota communities and their metabolites, suggesting a microbial contribution to the onset or progression of AID. The gut microbiota and its metabolites have been shown to influence immune functions and immune homeostasis both within the gut and systematically. ⋯ We review herein how gut microbiota and its metabolites regulate immune function, intestinal permeability and possibly AID pathological processes. Further, we describe the dysbiosis within the gut microbiota observed in different AID and speculate how restoring gut microbiota composition and its regulatory metabolites by dietary intervention including prebiotics and probiotics could help in preventing or ameliorating AID. Finally, we suggest that, given consistent observations of microbiota dysbiosis associated with AID and the ability of SCFA and BA to regulate intestinal permeability and inflammation, further mechanistic studies, examining how dietary microbiota modulation can protect against AID, hold considerable potential to tackle increased incidence of AID at the population level.
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Journal of autoimmunity · Aug 2018
ReviewThe diagnosis and clinical management of the catastrophic antiphospholipid syndrome: A comprehensive review.
The catastrophic antiphospholipid syndrome (CAPS) is a life-threating variant of the antiphospholipid syndrome characterized by the development of multiple thrombosis in a short period of time, usually ending up in the failure of function of several vital organs. Most CAPS episodes are related to a prothrombotic situation or precipitating factor such as infections, surgical procedures or malignant diseases. In patients with CAPS, the development of multiple thrombosis leads to an important cytokine release that worsens the already critical patient's situation. ⋯ Cyclophosphamide is recommended in those CAPS cases associated to systemic lupus erythematosus. Additionally, rituximab and eculizumab have been used in refractory cases. Mortality is still around 30% despite current treatment.
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Journal of autoimmunity · Jul 2018
TBK1: A key regulator and potential treatment target for interferon positive Sjögren's syndrome, systemic lupus erythematosus and systemic sclerosis.
Upregulation of type I interferons (IFN-I) is a hallmark of systemic autoimmune diseases like primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). Expression of IFN-I is induced by three different receptor families: Toll-like receptors (TLRs), RIG-like receptors (RLRs) and DNA-sensing receptors (DSRs). TANK-binding kinase (TBK1) is an important signaling hub downstream of RLRs and DSRs. TBK1 activates IRF3 and IRF7, leading to IFN-I production and subsequent induction of interferon stimulated genes (ISGs). The objective of this study was to explore the potential of BX795, an inhibitor of TBK1, to downregulate IFN-I activation in pSS, SLE and SSc. ⋯ TBK1 inhibition reduced expression of ISGs in PBMCs from IFNpos patients with systemic autoimmune diseases indicating TBK1 as a potential treatment target.
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Journal of autoimmunity · Jul 2017
FcRL4+ B-cells in salivary glands of primary Sjögren's syndrome patients.
Fc receptor-like protein 4 (FcRL4) is normally expressed on a small subset of mucosa-associated B-cells, as well as on mucosa-associated lymphoid tissue (MALT) lymphoma B-cells. Primary Sjögren's syndrome (pSS) patients have an increased risk of developing MALT lymphomas, preferentially in the parotid glands. For this reason we studied here by immunohistochemistry and mRNA analysis whether FcRL4 expressing B-cells are present in salivary gland tissue (labial and parotid) of pSS patients (n = 54) and non-pSS sicca patients (n = 16) and whether parotid gland MALT lymphomas in pSS patients (n = 49) also express this receptor. ⋯ In conclusion, intraepithelial FcRL4+ B-cells are present in the salivary glands of pSS patients. These cells are likely involved in the epithelial changes seen in pSS. Their enrichment in parotid glands may explain why MALT lymphomas in pSS patients preferentially develop at this specific location.
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Journal of autoimmunity · Jul 2017
NAD+ dependent deacetylase Sirtuin 5 rescues the innate inflammatory response of endotoxin tolerant macrophages by promoting acetylation of p65.
The induction and persistence of a hypo-inflammatory and immunosuppressive state in severe sepsis is commonly associated with increased risks of secondary infections and mortality. Toll-like receptor (TLR)-triggered inflammatory response of macrophages/monocytes plays an important role in determining the outcome of hyper-inflammation during the acute phase and the hypo-inflammation during immunosuppressive phase of sepsis. However, the mechanisms for controlling hypo-inflammatory response in endotoxin tolerant macrophages remain to be fully understood. ⋯ Interestingly, cytoplasmic SIRT5 counteracted the inhibitory effects of SIRT2 and enhanced the innate inflammatory responses in macrophages and even in endotoxin-tolerant macrophages by promoting acetylation of p65 and activation of NF-κB pathway. Mechanistically, SIRT5 competed with SIRT2 to interact with NF-κB p65, in a deacetylase activity-independent way, to block the deacetylation of p65 by SIRT2, which consequently led to increased acetylation of p65 and the activation of NF-κB pathway and its downstream cytokines. Our study discovered the new functions of different Sirtuin members in sepsis, indicating that targeting of Sirtuin family members at different sepsis phases can be helpful to precisely control the progression of sepsis.