scholarly journals A15 MICROBES MEDIATE FIBER-INDUCED INFLAMMATION IN IBD

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 17-19
Author(s):  
H Armstrong ◽  
R Dickner ◽  
A Rieger ◽  
I K Mander ◽  
J Jerasi ◽  
...  
Keyword(s):  
Immune Cells ◽  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Receptor Expression ◽  
Dietary Fibers ◽  
Microbial Composition ◽  
Inflammatory Cytokine Production

Abstract Background The etiology of inflammatory bowel diseases (IBD) remains unknown, although gut microorganisms and diet have been implicated. Dietary fibers pass through the bowel undigested and are fermented within the intestine by microbes, promoting gut health. However, many IBD patients describe experiencing sensitivity to fibres. Interestingly, fiber receptors on immune cells are able to interact with fibers typically found on the surface of fungal cells (which share properties with dietary fibers), for example, resulting in a paradoxical pro-inflammatory response. Aims As an altered microbial composition is a hallmark of IBD, we hypothesized that the loss of fiber fermenting-microbes populating the IBD gut could lead to dietary fibers not being efficiently broken down into their beneficial biproducts, resulting in binding of intact fibers to pro-inflammatory host cell receptors. This can ultimately drive pro-inflammatory responses and a microenvironment that promotes continued dysbiosis and increased pathogenicity of select microbes, as observed in IBD. Methods Fiber receptor expression gut was examined using immunohistochemistry and flow cytometry and demonstrated elevated receptor expression due to increased presence of immune cells in IBD patient biopsies. Cytokine secretion, in response to fiber (5mg/mL) or pre-fermented fibers, cultured with microbes of interest, was measured by ELISAs in cell lines in vitro and biopsy tissues cultured ex vivo. Results Whole-fibers induced pro-inflammatory cytokine production in macrophage, monocytes, and neutrophils. Specific microbes were capable of fermenting fiber, measured by gas chromatography. Pre-fermentation of fibers by these microbes reduced inflammatory cytokine production. The fiber oligofructose increased IL-1β in pediatric CD (n=44) and UC (n=29) biopsies cultured ex vivo but not in non-IBD (n=25). The increase was greater in patients with more severe disease. Pre-fermentation of oligofructose by bacteria reduced this secretion of IL-1β. Whole-microbe intestinal washes from severe IBD patients were unable to ferment oligofructose or reduce fiber-associated inflammation in macrophage cells compared to remission or non-IBD children. Statistical analysis of food frequency questionnaire (FFQ) data on fiber consumption demonstrated that fiber-associated inflammation in patient biopsies cultured ex vivo (ELISA and qPCR) correlated with fiber avoidance (FFQ). Conclusions Comparing in vitro findings to our patient FFQs, intestinal washes (microbe abundance), and detailed patient history will better define the relationship between microbes, dietary fibers, and gut inflammation in IBD. This will allow for tailored dietary intervention through dietary recommendations, prebiotic, and/or probiotic therapies. Funding Agencies CCCWeston Foundation, WCHRI

scholarly journals Functionally distinct subsets of human FOXP3+ Treg cells that phenotypically mirror effector Th cells

Blood ◽  
2012 ◽  
Vol 119 (19) ◽  
pp. 4430-4440 ◽  
Author(s):  
Thomas Duhen ◽  
Rebekka Duhen ◽  
Antonio Lanzavecchia ◽  
Federica Sallusto ◽  
Daniel J. Campbell
Keyword(s):  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Treg Cells ◽  
Receptor Expression ◽  
Inflammatory Cytokine Production ◽  
Th Cell ◽  
Different Types ◽  
Anti Inflammatory ◽  
Anti Inflammatory Cytokine

Abstract FOXP3+ regulatory T (Treg) cells are a broadly acting and potent anti-inflammatory population of CD4+ T cells essential for maintaining immune homeostasis and preventing debilitating autoimmunity. Based on chemokine receptor expression, we identified distinct populations of Treg cells in human blood expected to colocalize with different Th cell subsets. Although each population was functionally suppressive, they displayed unique patterns of pro- and anti-inflammatory cytokine production, differentially expressed lineage-specifying transcription factors, and responded differently to antigens associated with Th1 and Th17 responses. These results highlight a previously unappreciated degree of phenotypic and functional diversity in human Treg cells that allows subsets with unique specificities and immunomodulatory functions to be targeted to defined immune environments during different types of inflammatory responses.

scholarly journals A217 DEFINING THE RELATIONSHIP BETWEEN DIETARY FIBERS AND INFLAMMATORY RESPONSE IN PEDIATRIC INFLAMMATORY BOWEL DISEASES

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 90-92
Author(s):  
I K Mander ◽  
J Jerasi ◽  
R Dickner ◽  
M W Carroll ◽  
H Q Huynh ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Cell Lines ◽  
Immune Cells ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Dietary Fibers ◽  
Microbial Biodiversity ◽  
Bowel Diseases ◽  
Inflammatory Bowel

Abstract Background The incidence rates of inflammatory bowel diseases (IBD), Crohn disease (CD) and ulcerative colitis (UC) are increasing in children. Although the etiology of IBD is poorly understood, factors such as urban lifestyle, diet, increased hygiene, and reduced microbial biodiversity have been implicated as risk factors. Compositional changes and reduced microbial biodiversity have been linked to therapy failure in pediatric IBD. Non-digestible dietary carbohydrates, such as fiber, must undergo fermentation by gut microbiota within the large bowel, producing short chain fatty acids (SCFAs). Animal studies have shown that dietary fibers can inhibit IBD-associated inflammation, and clinical trials have demonstrated that SCFAs can prevent intestinal atrophy and allow for tissue recovery in IBD patients. In disease settings with altered gut microbes, fermentation of dietary fibers may be greatly affected. Unfermented fibers interact with receptors on host immune cells and can induce proinflammatory immune response, production of oxygen species and inflammation, or an inhibition of proinflammatory receptors. Aims Based on this rationale, we hypothesize that dysbiosis in the IBD gut leads to decreased fiber fermenting microbes, resulting in reduced SCFA production. This contributes to increased inflammatory responses both in in vitro cell lines, as well as ex vivo patient biopsies. Because intact fibers can bind to host cell receptors, this promotes inflammatory response and continued dysbiosis. Methods To assess effects of intact fiber on immune cells, macrophage and T-cell in vitro cultures were used to measure cytokine response to inulin (5mg/mL) and oligofructose (5mg/mL) through ELISAs/qPCR. These cell lines and ex vivo patient biopsies were treated with whole fibers and IL-1β secretion was measured. Fibers were also pre-fermented with microbes of interest or whole microbe patient intestinal washes and used to treat cell lines and patient biopsies. Results Whole fibers induced a pro-inflammatory response in macrophage cells but not T-cells, and this pro-inflammatory response was mitigated by pre-fermenting the fibers. Intestinal washes from severe IBD patients were unable to successfully ferment oligofructose or reduce fiber-associated inflammation in macrophage cell lines, whereas washes from remission or non-IBD samples reduced IL-1β. Oligofructose was found to increase IL-1β secretion in UC and CD patient biopsies, but not in non-IBD specimens. This increase was also correlated with disease severity. Conclusions These results indicate that a lack of fiber-fermenting microbes and presence of whole fibers can lead to pro-inflammatory responses, both in cell lines and patient biopsies. However, the presence of appropriate fermenting microbes can reduce fiber-associated inflammation. Funding Agencies CCCWCHRI, Weston Foundation

scholarly journals Glutathione Metabolism Contributes to the Induction of Trained Immunity

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 971
Author(s):  
Anaisa V. Ferreira ◽  
Valerie A.C.M. Koeken ◽  
Vasiliki Matzaraki ◽  
Sarantos Kostidis ◽  
Juan Carlos Alarcon-Barrera ◽  
...  
Keyword(s):  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Production Capacity ◽  
Innate Immune ◽  
Glutathione Metabolism ◽  
Nucleotide Polymorphisms ◽  
Inflammatory Cytokine Production ◽  
Trained Immunity

The innate immune system displays heterologous memory characteristics, which are characterized by stronger responses to a secondary challenge. This phenomenon termed trained immunity relies on epigenetic and metabolic rewiring of innate immune cells. As reactive oxygen species (ROS) production has been associated with the trained immunity phenotype, we hypothesized that the increased ROS levels and the main intracellular redox molecule glutathione play a role in the induction of trained immunity. Here we show that pharmacological inhibition of ROS in an in vitro model of trained immunity did not influence cell responsiveness; the modulation of glutathione levels reduced pro-inflammatory cytokine production in human monocytes. Single nucleotide polymorphisms (SNPs) in genes involved in glutathione metabolism were found to be associated with changes in pro-inflammatory cytokine production capacity upon trained immunity. Also, plasma glutathione concentrations were positively associated with ex vivo IL-1β production, a biomarker of trained immunity, produced by monocytes of BCG-vaccinated individuals. In conclusion, glutathione metabolism is involved in the induction of trained immunity, and future studies are warranted to explore its functional consequences in human diseases.

scholarly journals Leishmania donovani infection suppresses Allograft Inflammatory Factor-1 in monocytes and macrophages to inhibit inflammatory responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ricardo Louzada da Silva ◽  
Diana M. Elizondo ◽  
Nailah Z. D. Brandy ◽  
Naomi L. Haddock ◽  
Thomas A. Boddie ◽  
...  
Keyword(s):  
Immune Evasion ◽  
Inflammatory Cytokine ◽  
Leishmania Donovani ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Bone Marrow Cells ◽  
Parasitic Infections ◽  
Inflammatory Factor ◽  
Immune Functions ◽  
Inflammatory Cytokine Production

AbstractMacrophages and monocytes are important for clearance of Leishmania infections. However, immune evasion tactics employed by the parasite results in suppressed inflammatory responses, marked by deficient macrophage functions and increased accumulation of monocytes. This results in an ineffective ability to clear parasite loads. Allograft Inflammatory Factor-1 (AIF1) is expressed in myeloid cells and serves to promote immune responses. However, AIF1 involvement in monocyte and macrophage functions during parasitic infections has not been explored. This study now shows that Leishmania donovani inhibits AIF1 expression in macrophages to block pro-inflammatory responses. Mice challenged with the parasite had markedly reduced AIF1 expression in splenic macrophages. Follow-up studies using in vitro approaches confirmed that L. donovani infection in macrophages suppresses AIF1 expression, which correlated with reduction in pro-inflammatory cytokine production and increased parasite load. Ectopic overexpression of AIF1 in macrophages provided protection from infection, marked by robust pro-inflammatory cytokine production and efficient pathogen clearance. Further investigations found that inhibiting AIF1 expression in bone marrow cells or monocytes impaired differentiation into functional macrophages. Collectively, results show that AIF1 is a critical regulatory component governing monocyte and macrophage immune functions and that L. donovani infection can suppress the gene as an immune evasion tactic.

scholarly journals Antifungal antibiotics modulate the pro-inflammatory cytokine production and phagocytic activity of human monocytes in an in vitro sepsis model

Life Sciences ◽  
2015 ◽  
Vol 141 ◽  
pp. 128-136 ◽  
Author(s):  
Stefan Muenster ◽  
Christian Bode ◽  
Britta Diedrich ◽  
Sebastian Jahnert ◽  
Christina Weisheit ◽  
...  
Keyword(s):  
Phagocytic Activity ◽  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Human Monocytes ◽  
Inflammatory Cytokine Production ◽  
Sepsis Model ◽  
Antifungal Antibiotics

In vivo and in vitro effects of fluoroquinolones on lipopolysaccharide-induced pro-inflammatory cytokine production

2009 ◽  
Vol 15 (3) ◽  
pp. 168-173 ◽  
Author(s):  
Hiromi Ogino ◽  
Miho Fujii ◽  
Mariko Ono ◽  
Kayoko Maezawa ◽  
Junko Kizu ◽  
...  
Keyword(s):  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Inflammatory Cytokine Production ◽  
In Vitro Effects

Abstract 033: Differential Vasopressin Receptor Expression on CD4+ T Cells from Mouse and Human Preeclamptic Pregnancies

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Sabrina M Scroggins ◽  
Donna A Santillan ◽  
Jenna M Peterson ◽  
Nicole A Pearson ◽  
Jeremy A Sandgren ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Immune Modulation ◽  
Inflammatory Cytokine ◽  
Mononuclear Cells ◽  
Cytokine Production ◽  
Cell Activity ◽  
Tissue Bank ◽  
Receptor Expression ◽  
Inflammatory Cytokine Production

The pathogenesis of preeclampsia (PreE) involves the failure of the maternal immune system to normally tolerate the pregnancy. Inflammatory cytokines are elevated in PreE-affected women with a concurrent decrease in anti-inflammatory cytokine production. Consistent with what other groups have observed in mouse models of hypertension during pregnancy and in human PreE-affected pregnancies, we observed increased inflammatory cytokine production and CD4+ T helper populations in our chronic infusion of vasopressin (AVP) mouse model of PreE. The mechanisms of immune modulation by AVP have not been elucidated. As increased T cell activity is involved in the development of PreE, the objective of this study was to investigate if CD4+ T cells express AVP receptors. Splenic CD4+ T cells were negatively purified from C57BL/6J saline and AVP-infused (24 ng/hour) dams. Expression of AVP receptors (AVPR) 1a, 1b, 2, and the aminopeptidase LNPEP (catalyzes AVP degradation) was determined via qPCR. Raw cycle threshold (Ct) values were normalized (ΔCt) against the 18S rRNA endogenous control. Mouse CD4+ T cells express all AVP receptors and LNPEP. By ANOVA, AVPR2 is the highest expressed receptor in CD4+ T cells from saline (N=7, p=0.002) and AVP-infused (N=10, p<0.0001) dams. Human maternal mononuclear cells, obtained from the University of Iowa Maternal-Fetal Tissue Bank (IRB #200910784) from control and PreE-affected women, were similarly analyzed. As in mouse CD4+ T cells, human control (N=27, p<0.0001) and PreE-affected (N=26, p<0.0001) CD4+ T cells most highly expressed AVPR2. AVPR1a was also highly expressed while AVPR1b was the least expressed. CD4+ T cells isolated from human PreE-affected women expressed significantly lower AVPR1a (10.0±0.3 N=27 vs. 11.1±0.2 N=0.23, p=0.009) and increased LNPEP (17.2±0.5 N=27 vs. 15.1±0.3 N=26, p=0.001) than controls. Here, we demonstrate CD4+ T cells, both mouse and human, express AVP receptors and that 1a and 2 are highest expressed. Although the actions of AVP on the vasculature are primarily mediated through AVPR1a, these data suggest AVP may differentially act through AVPR1a to mediate immune responses during PreE.

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