scholarly journals Distinct microbial and immune niches of the human colon

Author(s):  
KR James ◽  
T Gomes ◽  
R Elmentaite ◽  
N Kumar ◽  
EL Gulliver ◽  
...  

AbstractGastrointestinal microbiota and immune cells interact closely and display regional specificity, but little is known about how these communities differ with location. Here, we simultaneously assess microbiota and single immune cells across the healthy, adult human colon, with paired characterisation of immune cells in the mesenteric lymph nodes, to delineate colonic immune niches at steady-state. We describe distinct T helper cell activation and migration profiles along the colon and characterise the transcriptional adaptation trajectory of T regulatory cells between lymphoid tissue and colon. Finally, we show increasing B cell accumulation, clonal expansion and mutational frequency from caecum to sigmoid colon, and link this to the increasing number of reactive bacterial species.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3235-3235 ◽  
Author(s):  
Marzia Palma ◽  
Aleksandra Krstic ◽  
Anna Berglöf ◽  
Qing Wang ◽  
Emelie Blomberg ◽  
...  

Abstract In this study we analyzed the very early effects of the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib on tumor and immune cells in 7 symptomatic, relapsed or refractory CLL patients during the first four weeks of treatment. Five of the patients had Rai stage IV at study entry and four patients had 17p deletion or TP53 mutation. Median number of previous treatment regimens was 2 (range 1-4). Peripheral blood (PB) samples were collected before (< 1 week) treatment start and at six different time points during the treatment (9 hours after treatment start on day 1; on day 2; day 4; day 8; day 15 and day 29). Fine needle aspiration of two pathological lymph nodes (LN) identified by ultrasound was performed before (< 1 week) treatment start and at day 2, day 8 and day 29. Flow-cytometry was performed to analyze the changes in the peripheral blood mononuclear cell populations in PB including CLL cells, Natural Killer (NK) cells, monocytes, dendritic cells (DC) and T cells memory subsets, helper subpopulations (Ths) and regulatory T cells (Tregs). Moreover, changes in expression of 18 B-cell activation and migration markers on CLL cells as well as T-cell activation and proliferation markers, were analyzed in paired LN and PB samples. Finally, plasma levels of 92 inflammation-related protein biomarkers were assessed by Multiplex Proximity Extension Assay (PEA). In six out of seven patients the size of the LN decreased gradually during the four weeks of observation, achieving complete clinical remission in three patients and partial remission in three other. In 5 evaluated patients, the CLL cell counts in PB increased already 9 hours after treatment start (fold increase 1.36-2.84). In all the patients, CLL cells were higher at day 2 and 8 compared to baseline (p=0.02), and decreased by day 29 to levels not significantly different from the baseline. Over the four weeks period CD4+ cells increased (p=0.03), while CD8+, NK, and NKT cells remained stable. The distribution of the CD4+ and CD8+ memory cell subsets remained unchanged. Th1 cells increased (p=0.01) while Th2, Th17 and Tregs were stable. Expression of Programmed cell death protein 1 (PD-1) and Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in T cells was unaffected. No effect was seen on CLL apoptosis. Proliferating (Ki67+) CLL cells, which at baseline varied between 1.2-10.8%, were not detected in blood after 1 week of treatment (p=0.0006). Ki67+ T cells were also eliminated (p=0.0007), but with a delayed kinetics (4 weeks). Paired LN and PB samples were screened for changes in 18 surface markers relevant for B-cell activation and migration. With the exception of CD23, whose expression was lower in PB compared to LN (p=0.02), no difference was observed in the expression of the other analyzed surface markers on CLL cells from the two different tumor compartments at baseline. CD5 expression remained stable during treatment, albeit decreasing significantly by day 29 in PB (p=0.02). Expression of CD20 decreased in both compartments at day 8 (p=0.02) and CD40 decreased at day 8 only in PB (p=0.02). CD69 expression (MFI) decreased both in PB and LN by day 8 (p=0.02), while the percentage of positive cells significantly dropped already at day 2 in PB (p=0.02) and from day 8 in LN (p=0.03). CD23 MFI decreased in the LN compartment already at day 2 (p=0.02), but the percentage of positive cells was significantly lower only at day 8 (p=0.03). Compared to LN, CD23 expression was lower in PB before treatment and therefore the significant drop both in MFI and percentage of positive cells was seen only after 4 weeks (p=0.02). No change in the expression of CD49d was observed. In 5 evaluable patients, the plasmacytoid DCs, undetectable at baseline, increased during treatment (p=0.06), while CD16+SLAN+monocytes decreased (p=0.06). Finally, plasma levels of 50 molecules were significantly changed at ≥ 1 time point during treatment. With the exception of CST5 and IL-17C, which were increased, the residual 48 proteins were all down-regulated, some of them (e.g. CCL3 and CCL4) already by 9 hours. The majority of the cytokines with significantly reduced levels are pro-inflammatory molecules. In conclusion, these data indicate that ibrutinib causes major changes both in CLL and bystander cells as well as in the levels of several inflammation-related protein biomarkers already shortly after treatment initiation. Disclosures Lundin: Janssen: Research Funding. Kimby:Gilead: Honoraria, Other: honoraria for educational lecture in meeting sponsored by Gilead; Roche: Other: Honoraria for lecture in educational meetings; Pfizer: Other: Research grant; Celgene: Other: Honoraria for lecture. educational meeting; Jansen: Membership on an entity's Board of Directors or advisory committees, Other: Honoraria for lecture at educational session. Österborg:Janssen: Honoraria, Research Funding.


Author(s):  
Carolin Wiechers ◽  
Mangge Zou ◽  
Eric Galvez ◽  
Michael Beckstette ◽  
Maria Ebel ◽  
...  

AbstractIntestinal Foxp3+ regulatory T cell (Treg) subsets are crucial players in tolerance to microbiota-derived and food-borne antigens, and compelling evidence suggests that the intestinal microbiota modulates their generation, functional specialization, and maintenance. Selected bacterial species and microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), have been reported to promote Treg homeostasis in the intestinal lamina propria. Furthermore, gut-draining mesenteric lymph nodes (mLNs) are particularly efficient sites for the generation of peripherally induced Tregs (pTregs). Despite this knowledge, the direct role of the microbiota and their metabolites in the early stages of pTreg induction within mLNs is not fully elucidated. Here, using an adoptive transfer-based pTreg induction system, we demonstrate that neither transfer of a dysbiotic microbiota nor dietary SCFA supplementation modulated the pTreg induction capacity of mLNs. Even mice housed under germ-free (GF) conditions displayed equivalent pTreg induction within mLNs. Further molecular characterization of these de novo induced pTregs from mLNs by dissection of their transcriptomes and accessible chromatin regions revealed that the microbiota indeed has a limited impact and does not contribute to the initialization of the Treg-specific epigenetic landscape. Overall, our data suggest that the microbiota is dispensable for the early stages of pTreg induction within mLNs.


2006 ◽  
Vol 72 (10) ◽  
pp. 6707-6715 ◽  
Author(s):  
Andrew B. Dalby ◽  
Daniel N. Frank ◽  
Allison L. St. Amand ◽  
Alison M. Bendele ◽  
Norman R. Pace

ABSTRACT Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed for a variety of inflammatory conditions; however, the benefits of this class of drugs are accompanied by deleterious side effects, most commonly gastric irritation and ulceration. NSAID-induced ulceration is thought to be exacerbated by intestinal microbiota, but previous studies have not identified specific microbes that contribute to these adverse effects. In this study, we conducted a culture-independent analysis of ∼1,400 bacterial small-subunit rRNA genes associated with the small intestines and mesenteric lymph nodes of rats treated with the NSAID indomethacin. This is the first molecular analysis of the microbiota of the rat small intestine. A comparison of clone libraries and species-specific quantitative PCR results from rats treated with indomethacin and untreated rats revealed that organisms closely related to Enterococcus faecalis were heavily enriched in the small intestine and mesenteric lymph nodes of the treated rats. These data suggest that treatment of NSAID-induced ulceration may be facilitated by addressing the microbiological imbalances.


2021 ◽  
Vol 22 (12) ◽  
pp. 6492
Author(s):  
Paola Giussani ◽  
Alessandro Prinetti ◽  
Cristina Tringali

Immunotherapy is now considered an innovative and strong strategy to beat metastatic, drug-resistant, or relapsing tumours. It is based on the manipulation of several mechanisms involved in the complex interplay between cancer cells and immune system that culminates in a form of immune-tolerance of tumour cells, favouring their expansion. Current immunotherapies are devoted enforcing the immune response against cancer cells and are represented by approaches employing vaccines, monoclonal antibodies, interleukins, checkpoint inhibitors, and chimeric antigen receptor (CAR)-T cells. Despite the undoubted potency of these treatments in some malignancies, many issues are being investigated to amplify the potential of application and to avoid side effects. In this review, we discuss how sphingolipids are involved in interactions between cancer cells and the immune system and how knowledge in this topic could be employed to enhance the efficacy of different immunotherapy approaches. In particular, we explore the following aspects: how sphingolipids are pivotal components of plasma membranes and could modulate the functionality of surface receptors expressed also by immune cells and thus their functionality; how sphingolipids are related to the release of bioactive mediators, sphingosine 1-phosphate, and ceramide that could significantly affect lymphocyte egress and migration toward the tumour milieu, in addition regulating key pathways needed to activate immune cells; given the renowned capability of altering sphingolipid expression and metabolism shown by cancer cells, how it is possible to employ sphingolipids as antigen targets.


2016 ◽  
Vol 34 (1-2) ◽  
pp. 43-50 ◽  
Author(s):  
Silvio Danese ◽  
Claudio Fiocchi

The proper delivery of immune cells throughout the host's various tissues and organs is essential to health, and abnormalities in the type and quantity of leukocyte distribution is usually associated with disease. Because of its size and presence of a very large amount of immunocytes in the mucosa and mesenteric lymph nodes, the gut is the recipient of a constant influx of leukocytes, a process tightly regulated by multiple factors. These include cell adhesion molecules on the leukocytes and their counter-receptors on the microvascular endothelial cells in the bowel wall, a number of chemokines and cytokines that help attracting immune cells, platelets, bacterial products, danger signals, the size of the vascular and lymphatic beds and the process of leukocyte exit and circulation in the blood and lymphatic fluid. The disruption of any of the above regulatory mechanism can lead to inflammation, as is the case for inflammatory bowel disease. Learning how leukocyte and endothelial cells mutually function in health and what goes wrong in inflammation offers the opportunity to intervene therapeutically and re-establish the normal crosstalk between leukocytes and endothelial cells.


2021 ◽  
Author(s):  
Yuya Tabuchi ◽  
Masao Katsushima ◽  
Yuri Nishida ◽  
Mirei Shirakashi ◽  
Hideaki Tsuji ◽  
...  

Abstract Background: Spondyloarthritis (SpA) is an autoimmune and autoinflammatory musculoskeletal disease characterised by systemic enthesitis. Recent research has focused on subclinical inflammatory bowel disease (IBD) in SpA pathogenesis. SKG mice, harbouring the Zap70 W163C mutation, increase autoreactive Th17 cells intrinsically, and show SpA features, including enteritis, after peritoneal injection of β-1,3- glucan under SPF conditions. In a conventional environment, they exhibit spontaneous arthritis with fungal factors. This study aimed to clarify whether oral dextran sulfate sodium (DSS) administration, utilised in IBD model mice, can provoke SpA features in SKG mice under SPF conditions, focusing on the relationship between gut microorganisms and SpA pathogenesis.Methods: SKG and BALB/c mice were administered oral DSS, and their body weights, arthritis, and enthesitis scores were recorded. In another cohorts, antibiotics (meropenem and vancomycin) or an anti-fungal agent (amphotericin B) were administered orally before DSS administration. The splenic Th1 and Th17 cell populations were examined before and after DSS administration using flow cytometry. Furthermore, the amount of circulating bacterial DNA in whole blood was measured by absolute quantitative polymerase chain reaction (qPCR), and the number and characteristics of bacterial species corresponding to these circulating DNA were analised by next-generation sequencing (NGS).Results: Ankle enthesitis as a peripheral SpA feature was elicited in half of DSS-administered SKG mice, and none of the BALB/c mice. Pre-administration of antibiotics suppressed enthesitis, whilst an anti-fungal agent could not. Th1 and Th17 cell levels in the spleen increased after DSS administration, and this was suppressed by pre-administration of antibiotics. SKG mice have a larger amount of bacterial DNA in whole blood than BALB/c mice before and one day after the initiation of DSS administration. The number of bacterial species in whole blood increased after DSS administration in SKG and BALB/c mice. Some genera and species significantly specific to the DSS-treated SKG mice group were also detected. Conclusion: Oral DSS administration alone elicited peripheral enthesitis in SKG mice with bacterial translocation accompanied by increased splenic Th1 and Th17 cell levels. Pre-administration of antibiotics ameliorated these DSS-induced SpA features. These findings suggest that intestinal bacterial leakage plays a pivotal role in SpA pathogenesis.


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