scholarly journals Gut microbiota–specific IgA+ B cells traffic to the CNS in active multiple sclerosis

2020 ◽  
Vol 5 (53) ◽  
pp. eabc7191
Author(s):  
Anne-Katrin Pröbstel ◽  
Xiaoyuan Zhou ◽  
Ryan Baumann ◽  
Sven Wischnewski ◽  
Michael Kutza ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
Gut Microbiota ◽  
Critical Role ◽  
Immunoglobulin A ◽  
Therapeutic Interventions ◽  
Bacterial Strains ◽  
Gut Microbiota Composition ◽  
Active Multiple Sclerosis

Changes in gut microbiota composition and a diverse role of B cells have recently been implicated in multiple sclerosis (MS), a central nervous system (CNS) autoimmune disease. Immunoglobulin A (IgA) is a key regulator at the mucosal interface. However, whether gut microbiota shape IgA responses and what role IgA+ cells have in neuroinflammation are unknown. Here, we identify IgA-bound taxa in MS and show that IgA-producing cells specific for MS-associated taxa traffic to the inflamed CNS, resulting in a strong, compartmentalized IgA enrichment in active MS and other neuroinflammatory diseases. Unlike previously characterized polyreactive anti-commensal IgA responses, CNS IgA cross-reacts with surface structures on specific bacterial strains but not with brain tissue. These findings establish gut microbiota–specific IgA+ cells as a systemic mediator in MS and suggest a critical role of mucosal B cells during active neuroinflammation with broad implications for IgA as an informative biomarker and IgA-producing cells as an immune subset to harness for therapeutic interventions.

scholarly journals The Emerging Role of the Gut Microbiome in the Cancer Response to Immune Checkpoint Inhibitors: A Narrative Review

2021 ◽  
Author(s):  
Ghada Araji ◽  
Julian Maamari ◽  
Fatima Ali Ahmad ◽  
Rana Zareef ◽  
Patrick Chaftari ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Gut Microbiome ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Therapeutic Interventions ◽  
The Impact ◽  
The Relationship ◽  
Gut Microbiota Composition

ABSTRACT The discovery of immune checkpoint inhibitors (ICIs) has revolutionized the care of cancer patients. However, the response to ICI therapy exhibits substantial interindividual variability. Efforts have been directed to identify biomarkers that predict the clinical response to ICIs. In recent years, the gut microbiome has emerged as a critical player that influences the efficacy of immunotherapy. An increasing number of studies have suggested that the baseline composition of a patient's gut microbiota and its dysbiosis are correlated with the outcome of cancer immunotherapy. This review tackles the rapidly growing body of evidence evaluating the relationship between the gut microbiome and the response to ICI therapy. Additionally, this review highlights the impact of antibiotic-induced dysbiosis on ICI efficacy and discusses the possible therapeutic interventions to optimize the gut microbiota composition to augment immunotherapy efficacy.

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

scholarly journals Sex differences in the phylum‐level human gut microbiota composition

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alexander Koliada ◽  
Vladislav Moseiko ◽  
Mariana Romanenko ◽  
Oleh Lushchak ◽  
Nadiia Kryzhanovska ◽  
...  
Keyword(s):  
Sex Differences ◽  
Gut Microbiota ◽  
Age Groups ◽  
Microbiota Composition ◽  
Human Gut ◽  
Cross Sectional ◽  
Total N ◽  
Human Gut Microbiota ◽  
Gut Microbiota Composition

Abstract Background Evidence was previously provided for sex-related differences in the human gut microbiota composition, and sex-specific discrepancy in hormonal profiles was proposed as a main determinant of these differences. On the basis of these findings, the assumption was made on the role of microbiota in the sexual dimorphism of human diseases. To date, sex differences in fecal microbiota were demonstrated primarily at lower taxonomic levels, whereas phylum-level differences between sexes were reported in few studies only. In the present population-based cross-sectional research, sex differences in the phylum-level human gut microbiota composition were identified in a large (total n = 2301) sample of relatively healthy individuals from Ukraine. Results Relative abundances of Firmicutes and Actinobacteria, as determined by qRT-PCR, were found to be significantly increased, while that of Bacteroidetes was significantly decreased in females compared to males. The Firmicutes to Bacteroidetes (F/B) ratio was significantly increased in females compared to males. Females had 31 % higher odds of having F/B ratio more than 1 than males. This trend was evident in all age groups. The difference between sexes was even more pronounced in the elder individuals (50+): in this age group, female participants had 56 % higher odds of having F/B ratio > 1 than the male ones. Conclusions In conclusion, sex-specific differences in the phylum-level intestinal microbiota composition were observed in the Ukraine population. The F/B ratio was significantly increased in females compared to males. Further investigation is needed to draw strong conclusions regarding the mechanistic basis for sex-specific differences in the gut microbiota composition and regarding the role of these differences in the initiation and progression of human chronic diseases.

scholarly journals B Cells and Antibodies as Targets of Therapeutic Intervention in Neuromyelitis Optica Spectrum Disorders

2021 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Jan Traub ◽  
Leila Husseini ◽  
Martin S. Weber
Keyword(s):  
B Cells ◽  
Neuromyelitis Optica ◽  
Plasma Cells ◽  
Treatment Options ◽  
Treatment Strategies ◽  
Therapeutic Interventions ◽  
Complement Factor ◽  
Major Subset ◽  
Spectrum Disorders

The first description of neuromyelitis optica by Eugène Devic and Fernand Gault dates back to the 19th century, but only the discovery of aquaporin-4 autoantibodies in a major subset of affected patients in 2004 led to a fundamentally revised disease concept: Neuromyelits optica spectrum disorders (NMOSD) are now considered autoantibody-mediated autoimmune diseases, bringing the pivotal pathogenetic role of B cells and plasma cells into focus. Not long ago, there was no approved medication for this deleterious disease and off-label therapies were the only treatment options for affected patients. Within the last years, there has been a tremendous development of novel therapies with diverse treatment strategies: immunosuppression, B cell depletion, complement factor antagonism and interleukin-6 receptor blockage were shown to be effective and promising therapeutic interventions. This has led to the long-expected official approval of eculizumab in 2019 and inebilizumab in 2020. In this article, we review current pathogenetic concepts in NMOSD with a focus on the role of B cells and autoantibodies as major contributors to the propagation of these diseases. Lastly, by highlighting promising experimental and future treatment options, we aim to round up the current state of knowledge on the therapeutic arsenal in NMOSD.

A Crucial Role for Diet in the Relationship Between Gut Microbiota and Cardiometabolic Disease

2020 ◽  
Vol 71 (1) ◽  
pp. 149-161 ◽  
Author(s):  
Ilias Attaye ◽  
Sara-Joan Pinto-Sietsma ◽  
Hilde Herrema ◽  
Max Nieuwdorp
Keyword(s):  
Gut Microbiota ◽  
Global Scale ◽  
Cardiometabolic Disease ◽  
Microbiota Composition ◽  
Dietary Interventions ◽  
Fermentable Carbohydrates ◽  
Cost Efficient ◽  
And Function ◽  
Gut Microbiota Composition

Cardiometabolic disease (CMD), such as type 2 diabetes mellitus and cardiovascular disease, contributes significantly to morbidity and mortality on a global scale. The gut microbiota has emerged as a potential target to beneficially modulate CMD risk, possibly via dietary interventions. Dietary interventions have been shown to considerably alter gut microbiota composition and function. Moreover, several diet-derived microbial metabolites are able to modulate human metabolism and thereby alter CMD risk. Dietary interventions that affect gut microbiota composition and function are therefore a promising, novel, and cost-efficient method to reduce CMD risk. Studies suggest that fermentable carbohydrates can beneficially alter gut microbiota composition and function, whereas high animal protein and high fat intake negatively impact gut microbiota function and composition. This review focuses on the role of macronutrients (i.e., carbohydrate, protein, and fat) and dietary patterns (e.g., vegetarian/vegan and Mediterranean diet) in gut microbiota composition and function in the context of CMD.

Bruton's tyrosine kinase inhibition in the treatment of preclinical models and multiple sclerosis

2021 ◽  
Vol 27 ◽  
Author(s):  
Anja Steinmaurer ◽  
Isabella Wimmer ◽  
Thomas Berger ◽  
Paulus Stefan Rommer ◽  
Johann Sellner
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
Tyrosine Kinase ◽  
B Cell ◽  
Bruton’S Tyrosine Kinase ◽  
Cumulative Number ◽  
Phase 2 ◽  
Bruton's Tyrosine Kinase ◽  
Relapsing Remitting

: Significant progress has been made in understanding the immunopathogenesis of multiple sclerosis (MS) over recent years. Successful clinical trials with CD20-depleting monoclonal antibodies have corroborated the fundamental role of B cells in the pathogenesis of MS and reinforced the notion that cells of the B cell lineage are an attractive treatment target. Therapeutic inhibition of Bruton's tyrosine kinase (BTK), an enzyme involved in B cell and myeloid cell activation and function, is regarded as a next-generation approach that aims to attenuate both errant innate and adaptive immune functions. Moreover, brain-penetrant BTK inhibitors may impact compartmentalized inflammation and neurodegeneration within the central nervous system by targeting brain-resident B cells and microglia, respectively. Preclinical studies in animal models of MS corroborated an impact of BTK inhibition on meningeal inflammation and cortical demyelination. Notably, BTK inhibition attenuated the antigen-presenting capacity of B cells and the generation of encephalitogenic T cells. Evobrutinib, a selective oral BTK inhibitor, has been tested recently in a phase 2 study of patients with relapsing-remitting MS. The study met the primary endpoint of a significantly reduced cumulative number of Gadolinium-enhancing lesions under treatment with evobrutinib compared to placebo treatment. Thus, the results of ongoing phase 2 and 3 studies with evobrutinib, fenobrutinib, and tolebrutinib in relapsing-remitting and progressive MS are eagerly awaited. This review article introduces the physiological role of BTK, summarizes the pre-clinical and trial evidence, and addresses the potential beneficial effects of BTK inhibition in MS.

scholarly journals Dissecting the Role of the Gut Microbiota and Diet on Visceral Fat Mass Accumulation (OR31-07-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Caroline Le Roy ◽  
Ruth Bowyer ◽  
Claire Steves ◽  
Tim Spector ◽  
Bell Jordana
Keyword(s):  
Vitamin E ◽  
Random Forest ◽  
Gut Microbiota ◽  
Fat Mass ◽  
Mediation Analysis ◽  
Visceral Fat ◽  
Nutrient Intake ◽  
Microbiota Composition ◽  
Gut Microbiota Composition

Abstract Objectives Accumulation of visceral fat mass (VFM) is a major risk factor for cardiovascular and metabolic disease. Both gut microbiota and diet have been shown to impact host adiposity in an interdependent manner, but the exact nature of their joint contributions has not been characterised. Here, we aimed to estimate and separate the effect of gut microbiota composition from that of nutrient intake on host VFM in of 1760 older female twins. Methods The gut microbiome profile was assessed by 16S sequencing. VFM was measured by DEXA whole body scan and nutrient intake was assessed through food frequency questionnaires. We used a combination of pair-wise associations, random forest modelling and mediation analysis to separate the effect of the gut microbiota and nutrients on VFM. Results Pairwise analyses revealed that 93 OTUs and 10 nutrients were significantly linked to VFM. Five of the 10 nutrients (fibre, trans fatty acids, magnesium, vitamin E and biotin) were also associated with 23% of the 93 VFM-associated OTUs. To separate the effects of the gut microbiota from nutrients on VFM we carried out conditional analyses. We observed that the majority (87%) of the 93 OTUs remained significantly associated with VFM irrespective of nutrient intake correction. In contrast, we observed that fibre, magnesium, biotin and vitamin E were no longer significantly associated with VFM when adjusting models for OTUs (P > 0.05), implying a role of the gut microbiota in mediating these nutrient effects on VFM. Formal mediation analysis revealed that the individual effect of fibre, biotin, magnesium and vitamin E on VFM were mediated at 69, 43, 41 and 31% respectively by OTUs. Moreover, we estimated that accumulated effect of OTUs on VFM (R2 = 0.19) was twice the one of nutrients (R2 = 0.11) and so were their prediction potential determined using random forest classification. Conclusions Our results suggest that while the role of certain nutrients on VFM appears to depend on gut microbiota composition, specific gut microbes may affect host adiposity regardless of dietary intake. The findings imply that the gut microbiota may have a greater contribution towards shaping host adiposity and VFM, compared to diet alone. Funding Sources We gratefully acknowledge support provided by the JPI HDHL funded DINAMIC consortium (administered by the MRC UK, MR/N030125/1). Supporting Tables, Images and/or Graphs

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