Regulatory T Cells in Systemic Sclerosis: a Comprehensive Review

Ocular Involvement in Systemic Sclerosis: Updated Review and New Insights on Microvascular Impairment

Systemic sclerosis (SSc) is a chronic multisystemic disease characterized by immunological activation, diffuse vasculopathy, and generalized fibrosis exhibiting a variety of symptoms. A recognized precursor of SSc is Raynaud's phenomenon, which is part of the very early disease of systemic sclerosis (VEDOSS) in combination with nailfold videocapillaroscopy (NVC) impairment. The pathophysiology of ocular involvement, alterations in internal organs, and body integumentary system involvement in SSc patients are complicated and poorly understood, with multiple mechanisms presumptively working together. The most prevalent ocular symptoms of SSc are abnormalities of the eyelids and conjunctiva as well as dry eye syndrome, due to fibroblasts' dysfunction and inflammation of the ocular surface. In particular, lagophthalmos, blepharophimosis limitation of eyelid motion, eyelid telangiectasia, and rigidity or tightening of the lids may affect up to two-third of the patients. In addition, reduction in central corneal thickness, iris defects and higher rates of glaucoma were reported. In the first reports based on retinography or fluorescein angiography, about 50% of SSc patients showed signs of vascular disease: peripheral artery occlusion, thinning of retinal pigment epithelium and choroidal capillaries, ischemic areas surrounded by intraretinal extravasation and microaneurysms, and peripheral capillary non-perfusion. Successively, thanks to the advent of optical coherence tomography angiography (OCTA), several studies highlighted significant impairment of either the choriocapillaris and retinal vascular plexuses, also correlating with NVC involvement and skin disease, even in VEDOSS disease. Given the sensitivity of this technique, ocular micro-vasculopathy may act as a tool for early SSc identification and discriminate between disease stages.

Imbalance of TH17/TREG cells in Tunisian patients with systemic sclerosis

Fibrosis is a pathological manifestation in which connective tissue replaces normal one. It can affect many tissues from the skin to internal organs such as the lungs. Manifestations of pulmonary involvement can be pulmonary arterial hypertension or pulmonary fibrosis. The latter one is currently the leading cause of death in various autoimmune diseases, including systemic sclerosis. Our study group consists of 50 patients with systemic sclerosis: 24 with limited cutaneous form and 26 with diffuse cutaneous form. This cohort was compared to 50 healthy controls (age and sex matched); our aim is to explore the distribution of TH17 cells (TH17) as well as regulatory T cells (TREG) and study their correlation with the disease's progress. Our results show an increase for IL17A in patients compared to controls and that this increase is correlated with a specific clinical involvement: Pulmonary fibrosis. This correlation suggests a crucial role of IL17A in fibrosis especially in systemic sclerosis. In addition, we have shown that the percentages of TH17 cells are higher in patients; however, the percentages of TREG cells are similar between patients and controls. A study of TREG cell activity showed that TREG lost suppressive activity by inactivating the FOXP3 transcription factor. This proves that despite their presence, TREG does not adequately carry out their regulatory activity. Finally, we analyzed the correlation between TH17/TREG and clinical damage; the results show a positive correlation with pulmonary involvement proving the role of TH17/TREG balance in induced fibrosis in systemic sclerosis. No significative difference was observed, for all the parameters, between the two different forms of the disease. In conclusion, the results associated with the TH17/TREG scale and their correlations with fibrosis in systemic sclerosis open a way for new tools to manage this autoimmune disease, which up to today has neither treatment nor accurate diagnosis.

"IL-2 immunotherapy for targeting regulatory T cells in autoimmunity"

FOXP3+ regulatory T cells (Treg) are indispensable for immune homoeostasis and for the prevention of autoimmune diseases. Interleukin-2 (IL-2) signalling is critical in all aspects of Treg biology. Consequences of defective IL-2 signalling are insufficient numbers or dysfunction of Treg and hence autoimmune disorders in human and mouse. The restoration and maintenance of immune homoeostasis remain central therapeutic aims in the field of autoimmunity. Historically, broadly immunosuppressive drugs with serious side-effects have been used for the treatment of autoimmune diseases or prevention of organ-transplant rejection. More recently, ex vivo expanded or in vivo stimulated Treg have been shown to induce effective tolerance in clinical trials supporting the clinical benefit of targeting natural immunosuppressive mechanisms. Given the central role of exogenous IL-2 in Treg homoeostasis, a new and promising focus in drug development are IL-2-based approaches for in vivo targeted expansion of Treg or for enhancement of their suppressive activity. In this review, we summarise the role of IL-2 in Treg biology and consequences of dysfunctional IL-2 signalling pathways. We then examine evidence of efficacy of IL-2-based biological drugs targeting Treg with specific focus on therapeutic candidates in clinical trials and discuss their limitations.

Further insight into systemic sclerosis from the vasculopathy perspective

Systemic sclerosis (SSc) is an autoimmune disease characterized by immune dysfunction, vascular system dysfunction, and tissue fibrosis. Vascular injury, vascular remodeling, and endothelial dysfunction are the hallmark pathological changes of the disease. In the early stages of SSc development, endothelial cell injury and apoptosis can lead to vascular and perivascular inflammation, oxidative stress, and tissue hypoxia, which can cause clinical manifestations in various organs from the skin to the parenchymal organs. Early diagnosis and rational treatment can improve patient survival and quality of life. Ancillary examinations such as nailfold capillaroscopy as well as optical coherence tomography can help early detect vascular injury in SSc patients. Studies targeting the mechanisms of vascular lesions will provide new perspectives for treatment of SSc.

Regulatory T cells: a new therapeutic link for Sjögren syndrome?

Great advancements have been made in understanding the pathogenesis of SS, but there remain unmet needs for effective and targeted treatments. Glandular and extraglandular dysfunction in SS is associated with autoimmune lymphocytic infiltration that invades the epithelial structures of affected organs. Regulatory T (Treg) cells are a subset of CD4+ T lymphocytes that maintain self-tolerance during physiological conditions. Besides inhibiting excessive inflammation and autoimmune response by targeting various immune cell subsets and tissues, Treg cells have also been shown to promote tissue repair and regeneration in pathogenic milieus. The changes of quantity and function of Treg cells in various autoimmune and chronic inflammatory disorders have been reported, owing to their effects on immune regulation. Here we summarize the recent findings from murine models and clinical data about the dysfunction of Treg cells in SS pathogenesis and discuss the therapeutic strategies of direct or indirect targeting of Treg cells in SS. Understanding the current knowledge of Treg cells in the development of SS will be important to elucidate disease pathogenesis and may guide research for successful therapeutic intervention in this disease.

Review of the Protective Mechanism of Paeonol on Cardiovascular Disease

Cardiovascular disease (CVD) is one of the leading causes of death in the world. Paeonol(Pae) is a phenolic component extracted from peony bark, peony root and Xu Changqing. Studies have shown that Pae can protect cardiomyocytes by inhibiting oxidative stress, promoting mitochondrial fusion, regulating mitochondrial autophagy and inhibiting inflammation. In addition, Pae improves ventricular remodeling by inhibiting myocardial apoptosis, hypertrophy and fibrosis. Pae also has a good protective effect on blood vessels by inhibiting vascular inflammation, reducing the expression of adhesion molecules, inhibiting vascular proliferation, and inhibiting oxidative stress and endoplasmic reticulum stress(ERS). Pae also has the effect of anti-endothelial cell senescence, promoting thrombus recanalization and vasodilating. In conclusion, the molecular targets of Pae are very complex, and the relationship between different targets and signaling pathways cannot be clearly explained, which requires us to use systems biology methods to further study specific molecular targets of Pae. It has to be mentioned that the bioavailability of Pae is poor, and some nanotechnology-assisted drug delivery systems improve the therapeutic effect of Pae. We reviewed the protective mechanism of paeonol on the cardiovascular system, hoping to provide help for drug development in the treatment of CVD.

Potential angiogenic, immunomodulatory, and antifibrotic effects of mesenchymal stem cell-derived extracellular vesicles in systemic sclerosis

Systemic sclerosis (SSc) is an intricate systemic autoimmune disease with pathological features such as vascular injury, immune dysregulation, and extensive fibrosis of the skin and multiple organs. Treatment options are limited; however, recently, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been acknowledged in preclinical and clinical trials as being useful in treating autoimmune diseases and are likely superior to MSCs alone. Recent research has also shown that MSC-EVs can ameliorate SSc and the pathological changes in vasculopathy, immune dysfunction, and fibrosis. This review summarizes the therapeutic effects of MSC-EVs on SSc and the mechanisms that have been discovered to provide a theoretical basis for future studies on the role of MSC-EVs in treating SSc.

Identification of Tregs-Related Genes with Molecular Patterns in Patients with Systemic Sclerosis Related to ILD

Background: Systemic Sclerosis (SSc) is an autoimmune disease that is characterized by vasculopathy, digital ulcers, Raynaud’s phenomenon, renal failure, pulmonary arterial hypertension, and fibrosis. Regulatory T (Treg) cell subsets have recently been found to play crucial roles in SSc with interstitial lung disease (ILD) pathogenesis. This study investigates the molecular mechanism of Treg-related genes in SSc patients through bioinformatic analyses. Methods: The GSE181228 dataset of SSc was used in this study. CIBERSORT was used for assessing the category and proportions of immune cells in SSc. Random forest and least absolute shrinkage and selection operator (LASSO) regression analysis were used to select the hub Treg-related genes. Results: Through bioinformatic analyses, LIPN and CLEC4D were selected as hub Treg-regulated genes. The diagnostic power of the two genes separately for SSc was 0.824 and 0.826. LIPN was associated with the pathway of aminoacyl−tRNA biosynthesis, Primary immunodeficiency, DNA replication, etc. The expression of CLEC4D was associated with the pathway of Neutrophil extracellular trap formation, PPAR signaling pathway, Staphylococcus aureus infection, Systemic lupus erythematosus, TNF signaling pathway, and Toll−like receptor signaling pathway. Conclusion: Through bioinformatic analyses, we identified two Treg-related hub genes (LIPN, CLEC4D) that are mainly involved in the immune response and metabolism of Tregs in SSc with ILD. Moreover, our findings may provide the potential for studying the molecular mechanism of SSc with ILD.

The Microbiome in Systemic Sclerosis: Pathophysiology and Therapeutic Potential

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune disease with unknown etiology characterized by multi-organ fibrosis. Despite substantial investigation on SSc-related cellular and molecular mechanisms, effective therapies are still lacking. The skin, lungs, and gut are the most affected organs in SSc, which act as physical barriers and constantly communicate with colonized microbiota. Recent reports have documented a unique microbiome signature, which may be the pathogenic trigger or driver of SSc. Since gut microbiota influences the efficacy and toxicity of oral drugs, evaluating drug-microbiota interactions has become an area of interest in disease treatment. The existing evidence highlights the potential of the microbial challenge as a novel therapeutic option in SSc. In this review, we have summarized the current knowledge about molecular mechanisms of SSc and highlighted the underlying role of the microbiome in SSc pathogenesis. We have also discussed the latest therapeutic interventions using microbiomes in SSc, including drug-microbiota interactions and animal disease models. This review aims to elucidate the pathophysiological connection and therapeutic potential of the microbiome in SSc. Insights into the microbiome will significantly improve our understanding of etiopathogenesis and developing therapeutics for SSc.

Changes in peripheral T-lymphocyte subsets and serum cytokines in patients with systemic sclerosis

Objective: T cells represent a predominant cell type in autoimmune disease. However, their exact roles are not fully clear in systemic sclerosis (SSc). This study aimed to mainly investigate the alteration in the absolute numbers of T-lymphocyte subsets and the serum levels of cytokines in SSc patients. Methods: A total of 76 patients with SSc and 76 age- and sex-matched healthy controls (HCs) were enrolled. The levels of circulating T cell subsets and serum cytokines were measured by flow cytometry. T cell subsets or serum cytokines correlations with disease activity and organ involvement were analyzed. Results: The absolute numbers of Th2 and Treg cells in SSc patients were lower than those in HCs (p < 0.05), resulting in the ratios of Th1/Th2 [25.01 (12.24, 38.61) vs. 11.64 (6.38, 20.34)] and Th17/Treg [0.42 (0.17, 0.66) vs. 0.17 (0.13, 0.29)] were increased significantly (p < 0.001). The absolute numbers of total T, Th, and Treg cells were negatively correlated with CRP (r = -0.406, p = 0.002; r = -0.263, p < 0.05; r = -0.367 p < 0.01). The serum levels of IL-2, SIL-2R, IL-6, IL-10, INF-γ, and TNF-α were significantly higher than those in HCs (p < 0.001). Increasing IL-2 in the wake of the augment of ESR (r = 0.671, p = 0.004), so did IL-6 (r = 0.378, p < 0.05). The ratio of Th17/Treg in SSc-ILD patients had lower levels than that in other patients [0.35 (0.14, 0.53) vs. 0.64 (0.26, 0.93) p = 0.028]; Treg cells were lessened in patients with Raynaud's phenomenon relative to controls [3.00 (2.41, 4.28) vs. 3.55 (2.86, 4.53) p < 0.05]. The levels of IL-2, IL-10 and INF-γ [3.32 (1.05,11.73) vs. 2.32 (0.44,6.45), p = 0.045], [8.08 (3.63, 355,77) vs. 4.89 (0.78, 21.44), p = 0.02], [6.31 (2.66, 44.03) vs. 4.03 (0.22, 16.96), p = 0.009] were elevated in patients with arthralgia, while the level of Th17 was decreased [0.62 (0.20,2.16) vs. 1.26 (0.22,10.93), p = 0.026]. ROC curve analysis yielded an optimal cut-off IL-2, IL-10, and INF-γ levels of 2.67, 5.93, and 5.32 pg/ml for the presence of arthralgia. Conclusion: We exhibited abnormalities in T subsets and the production of their cytokines in SSc, as compared with those in HCs. This may allow the pathogenesis of SSc and the development of novel therapeutic interventions aimed at targeting these cells and the cytokines they produce.

The Role of T Cells in Systemic Sclerosis: An Update

Systemic sclerosis (SSc) is a chronic disease characterized by microvasculopathy, autoantibodies (autoAbs), and fibrosis. The pathogenesis of the disease is incompletely understood. Microvasculopathy and autoAbs appear very early in the disease process. AutoAbs, such as those directed against DNA topoisomerase I (Topo I), are disease specific and associated with disease manifestations, and indicate activation of the adaptive immune system. B cells are involved in fibrosis in SSc. T cells are also involved in disease pathogenesis. T cells show signs of antigen-induced activation; T cells of TH2 type are increased and produce profibrotic cytokines interleukin (IL)-4, IL-13, and IL-31; CD4+ cytotoxic T lymphocytes are increased in skin lesions, and cause fibrosis and endothelial cell apoptosis; circulating T follicular helper (TFH) cells are increased in SSc produce IL-21 and promote plasmablast antibody production. On the other hand, regulatory T cells are impaired in SSc. These findings provide strong circumstantial evidence for T cell implication in SSc pathogenesis and encourage new T cell-directed therapeutic strategies for the disease.

A review on therapeutical potential of paeonol in atherosclerosis

The morbidity and mortality of atherosclerotic cardiovascular disease (ASCVD) is increasing year by year. Cortex Moutan is a traditional Chinese medicinal herb that has been widely used for thousands of years to treat a wide variety of diseases in Eastern countries due to its heat-clearing and detoxifying effects. Paeonol is a bioactive monomer extracted from Cortex Moutan, which has anti-atherosclerotic effects. In this article, we reviewed the pharmacological effects of paeonol against experimental atherosclerosis, as well as its protective effects on vascular endothelial cells, smooth muscle cells, macrophages, platelets, and other important cell types. The pleiotropic effects of paeonol in atherosclerosis suggest that it can be a promising therapeutic agent for atherosclerosis and its complications. Large-scale randomized clinical trials are warranted to elucidate whether paeonol are effective in patients with ASCVD.

Impact of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Rheumatic Disease Patients on T Helper Cell Differentiation

Complex pathogenesis of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is associated with an imbalance of various Th-cell subpopulations. Mesenchymal stem cells (MSCs) have the ability to restore this balance. However, bone marrow-derived MSCs of SLE and SSc patients exhibit many abnormalities, whereas the properties of adipose derived mesenchymal stem cells (ASCS) are much less known. Therefore, we examined the effect of ASCs obtained from SLE (SLE/ASCs) and SSc (SSc/ASCs) patients on Th subset differentiation, using cells from healthy donors (HD/ASCs) as controls. ASCs were co-cultured with activated CD4⁺ T cells or peripheral blood mononuclear cells. Expression of transcription factors defining Th1, Th2, Th17, and regulatory T cell (Tregs) subsets, i.e., T-bet, GATA3, RORc, and FoxP3, were analysed by quantitative RT-PCR, the concentrations of subset-specific cytokines were measured by ELISA, and Tregs formation by flow cytometry. Compared with HD/ASCs, SLE/ASCs and especially SSc/ASCs triggered Th differentiation which was disturbed at the transcription levels of genes encoding Th1- and Tregs-related transcription factors. However, we failed to find functional consequences of this abnormality, because all tested ASCs similarly switched differentiation from Th1 to Th2 direction with accompanying IFNγ/IL-4 ratio decrease, up-regulated Th17 formation and IL-17 secretion, and up-regulated classical Tregs generation.

Paeonol Attenuated Vascular Fibrosis Through Regulating Treg/Th17 Balance in a Gut Microbiota-Dependent Manner

Background: Paeonol (Pae) is a natural phenolic compound isolated from Cortex Moutan, which exhibits anti-atherosclerosis (AS) effects. Our previous work demonstrated that gut microbiota plays an important role during AS treatment as it affects the efficacy of Pae. However, the mechanism of Pae in protecting against vascular fibrosis as related to gut microbiota has yet to be elucidated. Objective: To investigate the antifibrosis effect of Pae on AS mice and demonstrate the underlying gut microbiota-dependent mechanism. Methods: ApoE^-/- mice were fed with high-fat diet (HFD) to replicate the AS model. H&E and Masson staining were used to observe the plaque formation and collagen deposition. Short-chain fatty acid (SCFA) production was analyzed through LC-MS/MS. The frequency of immune cells in spleen was phenotyped by flow cytometry. The mRNA expression of aortic inflammatory cytokines was detected by qRT-PCR. The protein expression of LOX and fibrosis-related indicators were examined by western blot. Results: Pae restricted the development of AS and collagen deposition. Notably, the antifibrosis effect of Pae was achieved by regulating the gut microbiota. LC-MS/MS data indicated that the level of SCFAs was increased in caecum contents. Additionally, Pae administration selectively upregulated the frequency of regulatory T (Treg) cells as well as downregulated the ratio of T helper type 17 (Th17) cells in the spleen of AS mice, improving the Treg/Th17 balance. In addition, as expected, Pae intervention can significantly downregulate the levels of proinflammatory cytokines IL-1β, IL-6, TNF-α, and IL-17 in the aorta, and upregulate the levels of anti-inflammatory factor IL-10, a marker of Treg cells. Finally, Pae's intervention in the gut microbiota resulted in the restoration of the balance of Treg/Th17, which indirectly downregulated the protein expression level of LOX and fibrosis-related indicators (MMP-2/9 and collagen I/III). Conclusion: Pae attenuated vascular fibrosis in a gut microbiota-dependent manner. The underlying protective mechanism was associated with the improved Treg/Th17 balance in spleen mediated through the increased microbiota-derived SCFA production. Collectively, our results demonstrated the role of Pae as a potential gut microbiota modulator to prevent and treat AS.

Interleukin-2 and regulatory T cells in rheumatic diseases

Failure of regulatory T (T_reg) cells to properly control immune responses leads invariably to autoimmunity and organ damage. Decreased numbers or impaired function of T_reg cells, especially in the context of inflammation, has been documented in many human autoimmune diseases. Restoration of T_reg cell fitness and/or expansion of their numbers using low-dose natural IL-2, the main cytokine driving T_reg cell survival and function, has demonstrated clinical efficacy in early clinical trials. Genetically modified IL-2 with an extended half-life and increased selectivity for T_reg cells is now in clinical development. Administration of IL-2 combined with therapies targeting other pathways involved in the expression of autoimmune diseases should further enhance its therapeutic potential. Ongoing clinical efforts that capitalize on the early clinical success of IL-2 treatment should bring the use of this cytokine to the forefront of biological treatments for autoimmune diseases.

Gut Microbiota And Inflammatory Disorders

The gut has been colonized with bacteria, fungi, viruses, archaea, eukarya. The human and bacterial cells are found in a 1:1 ratio, while the variance in the diversity of gut microbiota may result in Dysbiosis. Gut dysbiosis may result in various pathological manifestations. Beneficial gut microbiota may synthesize short-chain fatty acids like acetate, butyrate, propionate, while -gram-negative organisms are the primary source of LPS, a potent pro-inflammatory mediator. Both gut microbiota and microbial products may be involved in immunomodulation as well as inflammation. Prebiotics and probiotics are being explored as therapeutic agents against various inflammatory and autoimmune disorders. Here we discuss the molecular mechanisms involved in gut bacteria-mediated modulation of various inflammatory and autoimmune disorders.

Scalp and serum profiling of frontal fibrosing alopecia reveals scalp immune and fibrosis dysregulation with no systemic involvement

BACKGROUND

Frontal fibrosing alopecia (FFA) is a progressive, scarring alopecia of the frontotemporal scalp that poses a substantial burden on quality of life. Large-scale global profiling of FFA is lacking, preventing the development of effective therapeutics.

OBJECTIVE

To characterize FFA compared to normal and alopecia areata using broad molecular profiling and to identify biomarkers linked to disease severity.

METHODS

This cross-sectional study assessed 33,118 genes in scalp using RNA sequencing and 350 proteins in serum using OLINK high-throughput proteomics. Disease biomarkers were also correlated with clinical severity and a fibrosis gene set.

RESULTS

Genes differentially expressed in lesional FFA included markers related to Th1 (IFNγ/CXCL9/CXCL10), T-cell activation (CD2/CD3/CCL19/ICOS), fibrosis (CXCR3/FGF14/FGF22/VIM/FN1), T-regulatory (FOXP3/TGFB1/TGFB3), and Janus kinase/JAK (JAK3/STAT1/STAT4) (Fold changes [FCH]>1.5, FDR<.05 for all). Only one protein, ADM, was differentially expressed in FFA serum compared to normal (FCH>1.3, FDR<.05). Significant correlations were found between scalp biomarkers (IL-36RN/IL-25) and FFA severity, as well as between JAK/STAT and fibrosis gene-sets (r>.6; P <.05).

LIMITATIONS

This study was limited by a small sample size and predominantly female FFA patients.

CONCLUSION

Our data characterize FFA as an inflammatory condition limited to scalp, involving Th1/JAK skewing, with associated fibrosis and elevated T-regulatory markers, suggesting the potential for disease reversibility with JAK/STAT inhibition.

Plasticity of Treg and imbalance of Treg/Th17 cells in patients with systemic sclerosis modified by FK506

To determine the effects of Tacrolimus (FK506) on Treg cells and subpopulations in SSc patients and assess the ability of FK506 to modify the immune imbalance of Treg/Th17 cells. We analyzed PBMC from five SSc patients and six healthy control by flow cytometry after cultured with 0, 0.1, 1, or 10 ng/ml FK506 in vitro. The number of Treg cells decreased in SSc patients treated with FK506. The number of FrI cells were decreased in SSc following FK506 treatment. The drug did increase the frequency of FrII/Treg cells, but not FrII cells. However, FK506 significantly decreased FrIII in both SSc patients and controls. FK506 clearly decreased the numbers of Th17 cells and FoxP3⁺IL-17⁺ cells. The proliferation capacity of cells was also inhibited by FK506, which had a greater effect on FoxP3^- cells than FoxP3⁺ cells. FK506 did inhibit the proliferation of FrIII cells, but not FrI or FrII cells. Our study provides that FK506 reduced the number of FoxP3^low CD45RA^- T cells (FrIII) by inhibiting its proliferation. Therefore, FK506 modifies Treg cells and the immune imbalance between Tregs and Th17 cells in SSc patients.

Significance of alternative splicing in cancer cells

Objective

Alternative splicing can generate various structural and functional protein isoforms. Recently, accumulating evidence shows a relationship between alternative splicing and cancer. Cancer is a complex and chronic disease that involves malignant transformation. In this review, we consider alternative splicing events in relation to the hallmarks of cancer cells, and discuss current therapies to treat cancer-related to alternative splicing.

Data sources

Data cited in this article are from the PubMed and Embase database, primarily focusing on research published from 2000 to 2018.

Study selection

Articles were selected with the search terms “alternative splicing,” “cancer cell,” “tumor microenvironment,” and “therapy.”

Results

Alternative splicing plays an important role in tumorigenesis, development, and escape from cell death. Taking this trait of cancer cells into consideration will allow more definite diagnoses of cancer, and allow the development of more effective medicines to intervene in cancer that could focus on controlling alternative splicing or competitively binding to the final products.

Conclusions

Alternative splicing is common in cancer cells. Consideration of alternative splicing may allow different strategies for cancer therapy or the identification of novel biomarkers for cancer diagnosis.

Gastric Juice Expression of Th-17 and T-Reg Related Cytokines in Scleroderma Esophageal Involvement

BACKGROUND

Systemic sclerosis (SSc) is a connective tissue disorder which key feature is a fibrotic process. The role of Endothelin-1 (ET-1) and T-helper (Th)-1 cells in lung and skin fibrosis is well known, although Th17- and Treg-cells were found to be involved. However, no studies analyzed cytokines expression in gastric-juice of SSc patients. Our study aimed to evaluate proinflammatory and profibrotic cytokines in gastric-juice of SSc patients and to investigate their correlations with esophageal dysmotility.

METHODS

Patients performed upper-gastrointestinal-endoscopy with gastric-juice collection, esophageal manometry and thoracic CT-scan. GM-CSF, ET-1, Th-1 (IFN-γ, IL-1β, TNF-α, IL-2, IL-6, IL-9), Th-17 (IL-17, IL-21, IL-22, IL-23) and T-reg (IL-10, TGF-β) related cytokines were measured in 29 SSc-patients and 20 healthy-controls.

RESULTS

Patients showed significant lower levels of IL-6, IL-17, IL-22 and ET-1 (p < 0.005) compared with controls. Patients with atrophic gastritis presented significant lower levels of IL-2, IL-9, IL-6, TGF-β, GM-CSF, IL-17 and ET-1 (p < 0.005) compared to patients without gastritis. Increased values of IL-2, IL-9, IL-1β, IL-17, ET-1 and GM-CSF (p < 0.005) were observed in patients with esophageal impairment. This is the first report of cytokines measurement in gastric juice of patients with SSc. The high IL-17 concentrations in gastric-juice of scleroderma patients with esophageal dysmotility support the signature of Th-17 cells in scleroderma esophageal fibrosis.

Differential Th Cell-Related Immune Responses in Young Physically Active Men after an Endurance Effort

The participation of T cell subsets in the modulation of immunity in athletes triggered by maximal effort was investigated. In total, 80 physically active young men (range 16-20 years) were divided into 5 age groups: 16, 17, 18, 19, and 20 years old. They performed efficiency tests on mechanical treadmills until exhaustion. White blood cell (WBC) and lymphocyte (LYM) counts were determined, and the type 1 (Th1), type 2 (Th2) helper T cells, T helper 17 (Th17), and T regulatory (Treg) cell distribution and plasma levels of selected cytokines were analyzed. An increase in WBC and LYM counts after the test and in Th1 and Treg cells after the test and in recovery was observed. There were no changes in Th2 cells. An increase in interleukins (IL): IL-2 and IL-8 was observed. The IL-6 level was altered in all studied groups. IL-17A and interferon gamma (IFN-γ) levels were increased in all studied groups. The mechanism of differential T cell subset activation may be related to athletes' age. The novel findings of this study are the involvement of Th17 cells in post-effort immune responses and the participation of IL-6 in post-effort and the long-term biological effect of endurance effort.

Regulatory T cells in skin are uniquely poised to suppress profibrotic immune responses

At the center of fibrosing diseases is the aberrant activation of tissue fibroblasts. The cellular and molecular mechanisms of how the immune system augments fibroblast activation have been described; however, little is known about how the immune system controls fibroblast function in tissues. Here, we identify regulatory T cells (T_regs) as important regulators of fibroblast activation in skin. Bulk cell and single-cell analysis of T_regs in murine skin and lungs revealed that T_regs in skin are transcriptionally distinct and skewed toward T helper 2 (T_H2) differentiation. When compared with T_regs in lung, skin T_regs preferentially expressed high levels of GATA3, the master T_H2 transcription factor. Genes regulated by GATA3 were highly enriched in skin "T_H2 T_reg" subsets. In functional experiments, T_reg depletion resulted in a preferential increase in T_H2 cytokine production in skin. Both acute depletion and chronic reduction of T_regs resulted in spontaneous skin fibroblast activation, profibrotic gene expression, and dermal fibrosis, all of which were exacerbated in a bleomycin-induced murine model of skin sclerosis. Lineage-specific deletion of Gata3 in T_regs resulted in an exacerbation of T_H2 cytokine secretion that was preferential to skin, resulting in enhanced fibroblast activation and dermal fibrosis. Together, we demonstrate that T_regs play a critical role in regulating fibroblast activation in skin and do so by expressing a unique tissue-restricted transcriptional program that is mediated, at least in part, by GATA3.

Advances in the role of helper T cells in autoimmune diseases

Autoimmune diseases are primary immune diseases in which autoreactive antibodies or sensitized lymphocytes destroy and damage tissue and cellular components, resulting in tissue damage and organ dysfunction. Helper T cells may be involved in the pathogenesis of autoimmune diseases under certain conditions. This review summarizes recent research on the role of helper T cells in autoimmune diseases from two aspects, helper T cell-mediated production of autoantibodies by B cells and helper T cell-induced activation of abnormal lymphocytes, and provides ideas for the treatment of autoimmune diseases. The abnormal expression of helper T cells promotes the differentiation of B cells that produce autoantibodies, which leads to the development of different diseases. Among them, abnormal expression of Th2 cells and T follicular helper cells is more likely to cause antibody-mediated autoimmune diseases. In addition, abnormal activation of helper T cells also mediates autoimmune diseases through the production of abnormal cytokines and chemokines. Helper T cells play an essential role in the pathogenesis of autoimmune diseases, and a full understanding of their role in autoimmune diseases is helpful for providing ideas for the treatment of autoimmune diseases.

Regulatory T cells in inflammatory skin disease: from mice to humans

The skin is the largest organ in the body and one of the primary barriers to the environment. In order to optimally protect the host, the skin is home to numerous immune cell subsets that interact with each other and other non-immune cells to maintain organ integrity and function. Regulatory T cells (Tregs) are one of the largest immune cell subsets in skin. They play a critical role in regulating inflammation and facilitating organ repair. In doing so, they adopt unique and specialized tissue-specific functions. In this review, we compare and contrast the role of Tregs in cutaneous immune disorders from mice and humans, with a specific focus on scleroderma, alopecia areata, atopic dermatitis, cutaneous lupus erythematosus and psoriasis.

Emerging targets of disease-modifying therapy for systemic sclerosis

Systemic sclerosis (SSc) has the highest cause-specific mortality of all the connective tissue diseases, and the aetiology of this complex and heterogeneous condition remains an enigma. Current disease-modifying therapies for SSc predominantly target inflammatory and vascular pathways but have variable and unpredictable clinical efficacy, and none is curative. Moreover, many of these therapies possess undesirable safety profiles and have no appreciable effect on long-term mortality. This Review describes the most promising of the existing therapeutic targets for SSc and places them in the context of our evolving understanding of the pathophysiology of this disease. As well as taking an in-depth look at the immune, inflammatory, vascular and fibrotic pathways implicated in the pathogenesis of SSc, this Review discusses emerging treatment targets and therapeutic strategies. The article concludes with an overview of important unanswered questions in SSc research that might inform the design of future studies of treatments aimed at modifying the course of this disease.

Targeting FOXP3 complex ensemble in drug discovery

Forkhead Box P3 (FOXP3) is a key transcriptional regulator of regulatory T cells (Tregs), especially for its function of immune suppression. The special immune suppression function of Tregs plays an important role in maintaining immune homeostasis, and is related to several diseases including cancer, and autoimmune diseases. At the same time, FOXP3 takes a place in a large transcriptional complex, whose stability and functions can be controlled by various post-translational modification. More and more researches have suggested that targeting FOXP3 or its partners might be a feasible solution to immunotherapy. In this review, we focus on the transcription factor FOXP3 in Tregs, Treg functions in diseases and the FOXP3 targets.

T Cell Dysregulation in Non-silicotic Silica Exposed Workers: A Step Toward Immune Tolerance Breakdown

Background: Chronic silica exposure can lead to silicosis, complicated or not by autoimmune diseases (AID). The pathophysiology of silica-induced AID remains not fully understood, especially immune mechanisms that may develop in patients without yet established silicosis. We conducted a prospective clinical study to analyze the impact of crystalline silica (CS) on T cell phenotype and regulatory T cells (Tregs) frequency, as well as on auto-antibodies development in non-silicotic workers exposed to CS.

Methods: Workers with moderate to high exposure level to CS and aged between 30 and 60 years-old were considered for inclusion. Peripheral blood mononuclear cells were analyzed by flow cytometry. Auto-antibodies were screened in serum by immunofluorescence. Blood from 42 and 45 healthy subjects (HC) was used as control for T cell phenotype and serum analyses, respectively.

Results: Among the 63 included workers exposed to CS, 55 had full data available and were analyzed. Ten were exposed to CS for <5 years, 18 for 5–10 years and 27 for more than 10 years. The frequency of Tregs (CD4⁺CD25⁺CD127⁻FoxP3⁺) was significantly lower in CS exposed workers as compared to HC. We found an increased expression of the activation marker HLA-DR on T cells (CD3⁺, CD4⁺, and CD8⁺) of CS exposed workers as compared to HC. Tregs to activated T cells ratio was also lower in exposed subjects. In the latter, HLA-DR expression level and Tregs frequency were significantly associated with CS exposure duration. Serum autoantibody detection was significantly higher in CS exposed workers as compared to HC. Especially, among workers exposed more than 10 years, antinuclear antibodies and ANCA were detected in 44 and 22% among them, as compared to 5 and 2.5% in HC, respectively.

Conclusion: This work shows that CS exposure is associated with a decrease of Tregs frequency, an increase of T cell activation status, and a tolerance breakdown against auto-antigens. These results show that alterations of the T cell compartment can be detected early over the course of CS exposure, preceding silicosis development or AID onset.

Th1- and Th17-Related Cytokines in Venous and Arterial Blood of Sclerodermic Patients with and without Digital Ulcers

The earliest clinical manifestation of SSc is usually Raynaud's phenomenon, a small-arteries vasospasm driven by vascular tone dysregulation and microcirculatory abnormalities, resulting in digital ulcers (DU) in up to 50% of patients. Many cytokines as well as growth factors have been shown to play a role in promoting vascular smooth muscle cell proliferation and fibroblast activation, leading to ischemic damage as well as skin fibrosis. We aim to investigate a possible difference in venous and arterial blood levels of many cytokines (Th1- and Th17-related), GM-CSF, and endothelin-1 (ET1) in patients with and without DU. In the same patients, the correlations between capillary damage, evaluated by nailfold videocapillaroscopy (NVC), extension of skin fibrosis, calculated by modified Rodnan skin score (mRSS), and cytokines, ET-1, and GM-CSF levels were also measured. Patients with DU showed venous levels of IL-1β (p=0.024), IL-6 (p=0.012), IL-22(p=0.006), and TGF-β (p=0.046) significantly higher compared to arterial levels and arterial levels of GM-CSF and TNF-alpha significantly higher compared to venous levels (p < 0.001). NVC abnormalities were correlated with arterial TNFa and venous IL22, IL23, and IL17 levels and negatively correlated with venous ET-1 levels, whereas mRSS showed a negative correlation with IL-21(ρ = -0.427, p=0.050). The increased Th17-cytokine levels in venous compared to arterial blood of patients with DU suggest local cytokine production on ulcer site. The higher TNFa and GM-CSF levels in arterial blood of DU patients support the attempt to mitigate the hypoxic damage, and the correlation between Th17-cytokines, mRSS, NVC, and ET1 agrees with the potent profibrotic stimulus at the onset of the disease, which decreases as the SSc progresses.

The Fibrosis and Immunological Features of Hypochlorous Acid Induced Mouse Model of Systemic Sclerosis

Fibrotic animal models are critical for the pathogenesis investigations and drug explorations in systemic sclerosis (SSc). The bleomycin (BLM)-induced mouse model is the classical and most widely used fibrosis model. However, traditional subcutaneous injection of BLM rarely induced diffuse skin and lung lesions. Hypochlorous acid (HOCl)-induced mice are a more representative model that have diffuse cutaneous lesions, lung fibrosis and renal involvement. However, the fibrotic and immunological features of this model are not fully elucidated. Here, we injected BALB/c mice subcutaneously with HOCl used at different concentrations of HOCl (1:55, 1:70, and 1:110 NaClO: KH2PO4, hereafter named HOCl55, HOCl70, and HOCl110, respectively) for 6 weeks to induce fibrosis, and also used HOCl110 at different time course (4, 5, and 6 weeks). Morphological changes were observed via HE and Masson's trichrome staining. Immunohistochemistry or real-time PCR was used to detect inflammatory infiltrates, important fibrosis pathways and pro-inflammatory mediator expression. Flow cytometry was used to detect the alteration of immune cells in mouse spleen. Skin and lung fibrosis were most obvious in the HOCl55 group compared to lower concentration groups. In the HOCl110 group, dominant inflammatory infiltrates were found after 5 weeks, and significant fibrosis was found after 6 weeks. Then we explored the fibrosis and immunological profiles in the HOCl110 (6 weeks) group. Important fibrosis pathway proteins such as TGF-β, NF-κB, Smad3, p-Smad3, STAT3, and p-STAT3 were significantly elevated at week 6 in the HOCl110 group. Increased infiltration of CD4+T cells, CD8+T cells, CD20+B cells, and myofibroblasts was found both in skin and lung tissues. However, decreased CD4+T cells, CD8+T cells, monocytes and macrophages and increased CD19+B cells were found in the spleen tissues. The mRNA expression of fibrosis mediators such as IL-1β, IL-6, IL-17, IL-33, TNF-α, and CTGF was also upregulated in skin and lung tissues. In conclusion, HOCl induced fibrosis mouse model displayed systemic immune cell infiltration, pro-inflammatory mediator release, vasculopathy and fibrosis, which better mimicked human SSc than BLM-induced mice.

Immunopathogenesis of Juvenile Systemic Sclerosis

Juvenile-onset systemic sclerosis (jSSc) is a rare and severe autoimmune disease with associated life-threatening organ inflammation and evidence of fibrosis. The organ manifestations of jSSc resemble adult SSc, but with better outcomes and survival. The etiology of jSSc appears to reflect adult-onset SSc, with similar inflammatory mediators and autoantibodies, but with a significant population of children with uncharacterized anti-nuclear antibodies. The genetics of patients with jSSc differ from women with SSc, resembling instead the genes of adult males with SSc, with additional HLA genes uniquely associated with childhood-onset disease. Current treatments are aimed at inhibiting the inflammatory aspect of disease, but important mechanisms of fibrosis regulated by dermal white adipose tissue dendritic cells may provide an avenue for targeting and potentially reversing the fibrotic stage.

Pathophysiology of systemic sclerosis: current understanding and new insights

Introduction: Systemic sclerosis (SSc) is a complex autoimmune connective tissue disease characterized by chronic and progressive tissue and organ fibrosis with broad patient-to-patient variability. Some risk factors are known and include combination of persistent Raynaud's phenomenon, steroid hormone imbalance, selected chemicals, thermal, or other injuries. Endogenous and/or exogenous environmental trigger/risk factors promote epigenetic mechanisms in genetically primed subjects. Disease pathogenesis presents early microvascular changes with endothelial cell dysfunction, followed by the activation of mechanisms promoting their transition into myofibroblasts. A complex autoimmune response, involving innate and adaptive immunity with specific/functional autoantibody production, characterizes the disease. Progressive fibrosis and ischemia involve skin and visceral organs resulting in their irreversible damage/failure. Progenitor circulating cells (monocytes, fibrocytes), together with growth factors and cytokines participate in disease diffusion and evolution. Epigenetic, vascular and immunologic mechanisms implicated in systemic fibrosis, represent major targets for incoming disease modifying therapeutic approaches. Areas covered: This review discusses current understanding and new insights of SSc pathogenesis, through an overview of the most relevant advancements to present aspects and mechanisms involved in disease pathogenesis. Expert opinion: Considering SSc intricacy/heterogeneity, early combination therapy with vasodilators, immunosuppressive and antifibrotic drugs should successfully downregulate the disease progression, especially if started from the beginning.

T Cell Subsets' Distribution in Elite Karate Athletes as a Response to Physical Effort

Background

During karate fight muscles work at a very high intensity, and their contractions are extremely strong. The movement pattern contains a great number of feints, dodges, frequent changes in movements’ tempo and direction, hits and kicks, all of which is highly stressful for athlete’s organism, including the immune system.

Methods

T lymphocyte subsets’ distribution and selected cytokines in peripheral blood of three elite karate athletes aged 30 years old (range 21–31 years) with minimum 15 years of training experience were analysed in two experiments: at the beginning of the preparatory phase (a progressive test until exhaustion; an analysis of immune system’s selected parameters and cardiorespiratory fitness measures, including VO₂max, VE, AT, MVV, MET, Rf), and during the start-up period (Karate Championships; an analysis of selected parameters of the immune system).

Results

Maximal effort caused an increase in total lymphocyte percentage (p<0.05). A decrease in Th cells in recovery (p<0.05 compared to post-exercise), and an increase in Th naïve cells in recovery (p<0.05) were observed. A significant increase in CD8⁺ central memory cells (p<0.05) was found only after the progressive test, and no changes in both central and effector memory subsets of CD4⁺ cells during the first experiment. An increase (p<0.05) in Treg and Th1 and a decrease (p<0.05) in Th2 cells’ distribution during recovery time were found. Additionally, changes (p<0.05) in TNF-α, IL-6, IL-8, IL-10 and IL-12p70 were observed.

Conclusion

Post-effort disorder in immune balance activated compensation pathways involving CD4⁺ cells. Treg and Th1 cells seem to be subsets of key importance involved in the anabolic effect of physical effort, at least among karate athletes.

The role of metabolism in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is an immune-mediated autoimmune disease characterized by fibrosis and vascular abnormalities. The cellular and molecular mechanisms remain unclear, and current therapies are limited. Cell metabolism has been shown to play an essential role in cancer survival and tumour invasion as well as in rheumatic diseases such as systemic lupus erythematosus, rheumatoid arthritis and osteoarthritis. Although little is known about SSc, cell metabolism may provide new clues for understanding its pathogenesis. In this review, we summarize recent studies of metabolism in SSc and fibrotic disease, specifically focusing on glycolysis, fatty acid metabolism and oxidative stress. We highlight the role of metabolism in fibroblast differentiation and emphasize its potential therapeutic prospects in SSc.

Regulatory T Cells in Systemic Sclerosis

In recent years, accumulating evidence suggest that regulatory T cells (Tregs) are of paramount importance for the maintenance of immunological self-tolerance and immune homeostasis, even though they represent only about 5-10% of the peripheral CD4⁺ T cells in humans. Their key role is indeed supported by the spontaneous development of autoimmune diseases after Tregs depletion in mice. Moreover, there is also a growing literature that investigates possible contribution of Tregs numbers and activity in various autoimmune diseases. The contribution of Tregs in autoimmune disease has opened up a new therapeutic avenue based on restoring a healthy balance between Tregs and effector T-cells, such as Treg-based cellular transfer or low-dose IL-2 modulation. These therapies hold the promise of modulating the immune system without immunosuppression, while several issues regarding efficacy and safety need to be addressed. Systemic sclerosis (SSc) is an orphan connective tissue disease characterized by extensive immune abnormalities but also microvascular injury and fibrosis. Recently, data about the presence and function of Tregs in the pathogenesis of SSc have emerged although they remain scarce so far. First, there is a general agreement in the medical literature with regard to the decreased functional ability of circulating Tregs in SSc. Second the quantification of Tregs in patients have led to contradictory results; although the majority of the studies report reduced frequencies, there are conversely some indications suggesting that in case of disease activity circulating Tregs may increase. This paradoxical situation could be the result of a compensatory, but inefficient, amplification of Tregs in the context of inflammation. Nevertheless, these results must be tempered with regards to the heterogeneity of the studies for the phenotyping of the patients and of the most importance for Tregs definition and activity markers. Therefore, taking into account the appealing developments of Tregs roles in autoimmune diseases, together with preliminary data published in SSc, there is growing interest in deciphering Tregs in SSc, both in humans and mice models, to clarify whether the promises obtained in other autoimmune diseases may also apply to SSc.

Cutaneous Manifestations of Scleroderma and Scleroderma-Like Disorders: a Comprehensive Review

Scleroderma refers to an autoimmune connective tissue fibrosing disease, including three different subsets: localized scleroderma, limited cutaneous systemic sclerosis, and diffuse cutaneous systemic sclerosis with divergent patterns of organ involvement, autoantibody profiles, management, and prognostic implications. Although systemic sclerosis is considered the disease prototype that causes cutaneous sclerosis, there are many other conditions that can mimic and be confused with SSc. They can be classified into immune-mediated/inflammatory, immune-mediated/inflammatory with abnormal deposit (mucinoses), genetic, drug-induced and toxic, metabolic, panniculitis/vascular, and (para)neoplastic disorders according to clinico-pathological and pathogenetic correlations. This article reviews the clinical presentation with emphasis on cutaneous disease, etiopathogenesis, diagnosis, and treatment options available for the different forms of scleroderma firstly and for scleroderma-like disorders, including scleromyxedema, scleredema, nephrogenic systemic fibrosis, eosinophilic fasciitis, chronic graft-versus-host disease, porphyria cutanea tarda, diabetic stiff-hand syndrome (diabetic cheiroartropathy), and other minor forms. This latter group of conditions, termed also scleroderma mimics, sclerodermiform diseases, or pseudosclerodermas, shares the common thread of skin thickening but presents with distinct cutaneous manifestations, skin histology, and systemic implications or disease associations, differentiating each entity from the others and from scleroderma. The lack of Raynaud's phenomenon, capillaroscopic abnormalities, or scleroderma-specific autoantibodies is also important diagnostic clues. As cutaneous involvement is the earliest, most frequent and characteristic manifestation of scleroderma and sclerodermoid disorders, dermatologists are often the first-line doctors who must be able to promptly recognize skin symptoms to provide the affected patient a correct diagnosis and appropriate management.

Autologous hematopoietic stem cell transplantation in systemic sclerosis: A reset to tolerance?

Autologous hematopoietic stem cell transplantation (ASCT) is an effective therapy for refractory autoimmune disease, in particular diffuse cutaneous systemic sclerosis (dcSSc). ASCT is the only treatment that can induce long term remission in dcSSc. However, the mechanism of action of ASCT has not yet been fully elucidated. The current hypothesis is that ASCT induces a long term 'reset' of the immune system, but there is no clear definition yet of such an immunological 'reset to tolerance', nor has it been established how to distinguish a 'reset' from long term immunosuppression. Here, we review the literature on immunological changes after ASCT in dcSSc patients to gain more insight whether changes in immunological parameters can help elucidate the mechanism of action of ASCT. We identified 12 studies. While some immunological parameters could be correlated to clinical response, heterogeneity in the studies, short follow-up time and the small sample sizes preclude firm conclusions. Importantly, most patients displayed a sustained clinical response despite the presence of auto-antibodies or higher-than-normal concentrations of cytokines and proteins associated with disease activity. This suggests that the mechanism of ASCT may not be solely immunological. Future research should focus on larger cohorts of patients and also take functional evaluation of immune cells into account in order to determine whether ASCT induces long term immunosuppression or resets the immune system to tolerance. Answering this question is key to further optimizing ASCT for dcSSc patients.

Systemic sclerosis is associated with specific alterations in gastrointestinal microbiota in two independent cohorts

OBJECTIVE

To compare faecal microbial composition in patients with systemic sclerosis (SSc) from 2 independent cohorts with controls and to determine whether certain genera are associated with SSc-gastrointestinal tract (GIT) symptoms.

DESIGN

Adult patients with SSc from the University of California, Los Angeles (UCLA) and Oslo University Hospital (OUH) and healthy controls participated in this study (1:1:1). All participants provided stool specimens for 16S rRNA sequencing. Linear discriminant analysis effect size demonstrated genera with differential expression in SSc. Differential expression analysis for sequence count data identified specific genera associated with GIT symptoms as assessed by the GIT 2.0 questionnaire.

RESULTS

The UCLA-SSc and OUH-SSc cohorts were similar in age (52.1 and 60.5 years, respectively), disease duration (median (IQR): 6.6 (2.5-16.4) and 7.0 (1.0-19.2) years, respectively), gender distribution (88% and 71%, respectively), and GIT symptoms (mean (SD) total GIT 2.0 scores of 0.7 (0.6) and 0.6 (0.5), respectively). Principal coordinate analysis illustrated significant microbial community differences between SSc and controls (UCLA: p=0.001; OUH: p=0.002). Patients with SSc had significantly lower levels of commensal genera deemed to protect against inflammation, such as Bacteroides (UCLA and OUH), Faecalibacterium (UCLA), Clostridium (OUH); and significantly higher levels of pathobiont genera, such as Fusobacterium (UCLA), compared with controls. Increased abundance of Clostridium was associated with less severe GIT symptoms in both cohorts.

CONCLUSIONS

The present analysis detected specific aberrations in the lower GIT microbiota of patients with SSc from 2 geographically and ethnically distinct cohorts. These findings suggest that GIT dysbiosis may be a pathological feature of the SSc disease state.