scholarly journals Secreted microbial metabolites modulate gut immunity and inflammatory tone

2019 ◽  
Author(s):  
Rabina Giri ◽  
Emily C. Hoedt ◽  
Khushi Shamsunnahar ◽  
Michael A. McGuckin ◽  
Mark Morrison ◽  
...  

AbstractEvidence is emerging that microbiome–immune system crosstalk regulates the tenor of host intestinal immunity and predisposition to inflammatory bowel disease (IBD). We identified five NF-κB suppressive strains affiliated with Clostridium clusters IV, XIVa and XV that independently suppressed secretion of the chemokine IL-8 by peripheral blood mononuclear cells and gut epithelial organoids from healthy human subjects, as well as patients with the predominant IBD subtypes, Crohn’s disease and ulcerative colitis. The NF-κB suppressive Clostridium bolteae AHG0001, but not C. bolteae BAA-613, suppressed cytokine-driven inflammatory responses and endoplasmic reticulum stress in gut epithelial organoids derived from Winnie mice that develop spontaneous colitis. This predicted in vivo responses thereby validating a precision medicine approach to treat Winnie colitis and suggesting the microbiome may function as an extrinsic regulator of host immunity. Finally, we identified a novel molecule associated with NF-κB suppression indicating gut bacteria could be harnessed to develop new therapeutics.

1998 ◽  
Vol 66 (5) ◽  
pp. 2154-2162 ◽  
Author(s):  
Carla Bromuro ◽  
Roberto La Valle ◽  
Silvia Sandini ◽  
Francesca Urbani ◽  
Clara M. Ausiello ◽  
...  

ABSTRACT The 70-kDa recombinant Candida albicans heat shock protein (CaHsp70) and its 21-kDa C-terminal and 28-kDa N-terminal fragments (CaHsp70-Cter and CaHsp70-Nter, respectively) were studied for their immunogenicity, including proinflammatory cytokine induction in vitro and in vivo, and protection in a murine model of hematogenous candidiasis. The whole protein and its two fragments were strong inducers of both antibody (Ab; immunoglobulin G1 [IgG1] and IgG2b were the prevalent isotypes) and cell-mediated immunity (CMI) responses in mice. CaHsp70 preparations were also recognized as CMI targets by peripheral blood mononuclear cells of healthy human subjects. Inoculation of CaHsp70 preparations into immunized mice induced rapid production of interleukin-6 (IL-6) and tumor necrosis factor alpha, peaking at 2 to 5 h and declining within 24 h. CaHsp70 and CaHsp70-Cter also induced gamma interferon (IFN-γ), IL-12, and IL-10 but not IL-4 production by CD4+ lymphocytes cocultured with splenic accessory cells from nonimmunized mice. In particular, the production of IFN-γ was equal if not superior to that induced in the same cells by whole, heat-inactivated fungal cells or the mitogenic lectin concanavalin A. In immunized mice, however, IL-4 but not IL-12 was produced in addition to IFN-γ upon in vitro stimulation of CD4+ cells with CaHsp70 and CaHsp70-Cter. These animals showed a decreased median survival time compared to nonimmunized mice, and their mortality was strictly associated with organ invasion by fungal hyphae. Their enhanced susceptibility was attributable to the immunization state, as it did not occur in congenitally athymic nude mice, which were unable to raise either Ab or CMI responses to CaHsp70 preparations. Together, our data demonstrate the elevated immunogenicity of CaHsp70, with which, however, no protection against but rather some enhancement of Candida infection seemed to occur in the mouse model used.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xiaoyi Shi ◽  
Chunhui Lai ◽  
Lianyu Zhao ◽  
Mingying Zhang ◽  
Xi Liu ◽  
...  

IL-37 is a cytokine that plays critical protective roles in many metabolic inflammatory diseases, and its therapeutic potential has been confirmed by exogenous IL-37 administration. However, its regulatory mechanisms remain unclear. U937 cells were treated with autophagy-modifying reagents (3-MA, chloroquine, and rapamycin) with or without LPS stimulation. Thereafter, IL-37 expression and autophagic markers (Beclin1, P62/SQSTM1, and LC3) were determined. For regulatory signal pathways, phosphorylated proteins of NF-κB (p65 and IκBα), AP-1 (c-Fos/c-Jun), and MAPK signal pathways (Erk1/2 and p38 MAPK) were quantified, and the agonists and antagonists of MAPK and NF-κB pathways were also used. Healthy human peripheral blood mononuclear cells were treated similarly to confirm our results. Four rhesus monkeys were also administered chloroquine to evaluate IL-37 induction in vivo and its bioactivity on CD4 proliferation and activation. IL-37 was upregulated by rapamycin and chloroquine in both U937 cells and human PBMCs in the presence of LPS. IL-37 was preferentially induced in autophagic cells associated with LC3 conversion. AP-1 and p65 binding motifs could be deduced in the sequence of the IL-37 promoter. Inductive IL-37 expression was accompanied with increased phosphorylated Erk1/2 and AP-1 and could be completely abolished by an Erk1/2 inhibitor or augmented by Erk1/2 agonists. In monkeys, chloroquine increased IL-37 expression, which was inversely correlated with CD4 proliferation and phosphorylated STAT3. IL-37 levels were induced by rapamycin and chloroquine through the LC3, Erk1/2, and NF-κB/AP-1 pathways. Functional IL-37 could also be induced in vivo.


2012 ◽  
Vol 112 (6) ◽  
pp. 937-943 ◽  
Author(s):  
A. J. Hajari ◽  
D. A. Yablonskiy ◽  
A. L. Sukstanskii ◽  
J. D. Quirk ◽  
M. S. Conradi ◽  
...  

Despite decades of research into the mechanisms of lung inflation and deflation, there is little consensus about whether lung inflation occurs due to the recruitment of new alveoli or by changes in the size and/or shape of alveoli and alveolar ducts. In this study we use in vivo 3He lung morphometry via MRI to measure the average alveolar depth and alveolar duct radius at three levels of inspiration in five healthy human subjects and calculate the average alveolar volume, surface area, and the total number of alveoli at each level of inflation. Our results indicate that during a 143 ± 18% increase in lung gas volume, the average alveolar depth decreases 21 ±5%, the average alveolar duct radius increases 7 ± 3%, and the total number of alveoli increases by 96 ± 9% (results are means ± SD between subjects; P < 0.001, P < 0.01, and P < 0.00001, respectively, via paired t-tests). Thus our results indicate that in healthy human subjects the lung inflates primarily by alveolar recruitment and, to a lesser extent, by anisotropic expansion of alveolar ducts.


2004 ◽  
Vol 91 (1) ◽  
pp. 101-106 ◽  
Author(s):  
André Grandgirard ◽  
Lucy Martine ◽  
Luc Demaison ◽  
Catherine Cordelet ◽  
Corinne Joffre ◽  
...  

The oxidised derivatives of phytosterols (oxyphytosterols) were identified in plasma samples from thirteen healthy human volunteers, using MS. All the samples contained noticeable quantities of (24R)-5β,6β-epoxy-24-ethylcholestan-3β-ol (β-epoxysitostanol) and (24R)-ethylcholestan-3β,5α,6β-triol (sitostanetriol) and also trace levels of (24R)-5α,6α-epoxy-24-ethylcholestan-3β-ol (α-epoxysitostanol), (24R)-methylcholestan-3β,5α,6β-triol (campestanetriol) and (24R)-ethylch olest-5-en-3β-ol-7-one(7-ketositosterol). The amounts of these oxyphytosterols in plasma varied from 4·8 to 57·2 ng/ml. There are two possibilities concerning the origin of these compounds. First, they could come from the small amounts of oxyphytosterols in food. Second, they could originate from the in vivo oxidation of phytosterols in plasma. Very few data actually exist concerning these compounds. Their identification in human samples suggests that further research is necessary in this field.


1999 ◽  
Vol 6 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Latchezar Traykov ◽  
Bertrand Tavitian ◽  
Antoinette Jobert ◽  
Francois Boller ◽  
Francoise Forette ◽  
...  

2016 ◽  
Vol 54 ◽  
pp. 149-157 ◽  
Author(s):  
Naoki Kanegawa ◽  
Karin Collste ◽  
Anton Forsberg ◽  
Martin Schain ◽  
Ryosuke Arakawa ◽  
...  

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