Prolonged interferon-γ exposure decreases ion transport, NKCC1, and Na+-K+-ATPase expression in human intestinal xenografts in vivo

2004 ◽  
Vol 286 (1) ◽  
pp. G157-G165 ◽  
Author(s):  
Lone S. Bertelsen ◽  
Lars Eckmann ◽  
Kim E. Barrett
Keyword(s):  
Ion Transport ◽  
Prolonged Exposure ◽  
Intestinal Inflammation ◽  
Interferon Γ ◽  
Α Subunit ◽  
Ussing Chambers ◽  
Epithelial Cell Lines ◽  
Ifn Γ ◽  
Small Intestinal

IFN-γ is elevated in intestinal inflammation and alters barrier and transport functions in human colonic epithelial cell lines, but its effects on normal human small intestinal epithelium in vivo are poorly defined. We investigated effects of prolonged IFN-γ exposure on ion transport and expression of transporters by using human fetal small intestinal xenografts. Xenograft-bearing mice were injected with IFN-γ, and 24 h later xenografts were harvested and mounted in Ussing chambers. Baseline potential difference (PD) was not affected by IFN-γ treatment. However, conductance was enhanced and agonist-stimulated ion transport was decreased. IFN-γ also decreased expression of the Na+-K+-2Cl- cotransporter and the α-subunit of Na+-K+-ATPase compared with controls, whereas levels of the calcium-activated Cl- channel and CFTR were unaltered. Thus prolonged exposure to IFN-γ leads to decreased ion secretion due, in part, to decreased ion transporter levels. These findings demonstrate the implications of elevated IFN-γ levels in human small intestine and validate the human intestinal xenograft as a model to study chronic effects of physiologically relevant stimuli.

Converging effects of a Bifidobacterium and Lactobacillus probiotic strain on mouse intestinal physiology

2014 ◽  
Vol 307 (2) ◽  
pp. G241-G247 ◽  
Author(s):  
Kevin W. Lomasney ◽  
John F. Cryan ◽  
Niall P. Hyland
Keyword(s):  
Ion Transport ◽  
Water Content ◽  
Short Circuit ◽  
Intestinal Transit ◽  
Current Response ◽  
Dependent Manner ◽  
Small Intestinal Transit ◽  
Ussing Chambers ◽  
Small Intestinal

Evidence has grown to support the efficacy of probiotics in the management of gastrointestinal disorders, many of which are associated with dysregulated fluid and electrolyte transport. A growing body of evidence now suggests that the host microbiota and probiotics can influence intestinal ion transport and that these effects often occur in a strain-dependent manner. In this study, we sought to investigate the effects of two therapeutically relevant organisms, Bifidobacterium infantis 35624 and Lactobacillus salivarius UCC118, on small intestinal transit, fecal output and water content, transepithelial resistance (TER), and colonic secretomotor function. Mice fed either strain displayed significantly reduced small intestinal transit in vivo, though neither strain influenced fecal pellet output or water content. Colon from mice fed both organisms displayed increased colonic TER, without a concomitant change in the gene expression of the tight junction proteins claudin 1 and occludin. However, L. salivarius UCC118 selectively inhibited neurally evoked ion secretion in tissues from animals fed this particular probiotic. Consistent with this finding, the neurotoxin tetrodotoxin (TTx) significantly inhibited the short-circuit current response induced by L. salivarius UCC118 following addition to colonic preparations in Ussing chambers. Responses to B. infantis 35624 also displayed sensitivity to TTx, although to a significantly lesser degree than L. salivarius UCC118. Both strains similarly inhibited cholinergic-induced ion transport after addition to Ussing chambers. Taken together, these data suggest that B. infantis 35624 and L. salivarius UCC118 may be indicated in disorders associated with increased small intestinal transit, and, in particular for L. salivarius UCC118, neurally mediated diarrhea.

Characterization of the human intestinal CD98 promoter and its regulation by interferon-γ

2007 ◽  
Vol 292 (2) ◽  
pp. G535-G545 ◽  
Author(s):  
Yutao Yan ◽  
Guillaume Dalmasso ◽  
Shanthi Sitaraman ◽  
Didier Merlin
Keyword(s):  
Transcriptional Regulation ◽  
Intestinal Inflammation ◽  
Direct Sequencing ◽  
Interferon Γ ◽  
Initiation Site ◽  
Start Codon ◽  
Transcriptional Initiation ◽  
Ifn Γ

Growing evidence that epithelial CD98 plays an important role in intestinal inflammation focused our interest to investigate the transcriptional regulation of CD98. Our mouse-based in vivo and in vitro experiments revealed that epithelial colonic CD98 mRNA expression was transcriptionally increased in intestinal inflammation. We then isolated and characterized a 5′-flanking fragment containing the promoter region required for CD98 gene transcription. Primer extension and rapid amplification of 5′-cDNA ends were used to map a transcriptional initiation site 129 bp upstream from the translational start codon (ATG). Direct sequencing of the 5′-flanking region revealed the presence of four GC-rich stimulating protein (Sp)1 binding domains, one NF-κB binding domain, and no TATA box. Binding of Sp1 [Sp1(−874), SP1(−386), Sp1(−187), and Sp1(−177)] and NF-κB [NF-κB(−213)] to the promoter was confirmed by EMSA and supershift assays. Furthermore, chromatin immunoprecipitation experiments showed the in vivo DNA-Sp1 and DNA-NF-κB interactions under basal and IFN-γ-stimulated conditions. Reporter genes driven by serially truncated and site-mutated CD98 promoters were used to examine basal and IFN-γ-responsive transcription in transiently transfected Caco2-BBE cells. Our results revealed that Sp1(−187), Sp1(−177), and the NF-κB binding site were essential for basal and IFN-γ-stimulated CD98 promoter activities, whereas Sp1(−874) and Sp1(−386) were not. The results from additional site-mutated CD98 promoters suggested that Sp1(−187), Sp1(−177), and the NF-κB site may cooperate in mediating basal and IFN-γ-stimulated CD98 promoter activities. Finally, we demonstrated that a reduction of Sp1 or NF-κB expression reduced CD98 protein expression in unstimulated and IFN-γ-stimulated Caco2-BBE cells. Collectively, these findings indicate that the Sp1 and NF-κB transcription factors are likely to play a significant role in IFN-γ-mediated transcriptional regulation of CD98 in the intestinal epithelium, providing new insights into the regulation of CD98 expression in intestinal inflammation.

scholarly journals Requirements for in vivo IFN-γ induction by live microfilariae of the parasitic nematode, Brugia malayi

Parasitology ◽  
2000 ◽  
Vol 120 (6) ◽  
pp. 631-640 ◽  
Author(s):  
R. A. LAWRENCE ◽  
J. E. ALLEN ◽  
C. A. GRAY
Keyword(s):  
Human Disease ◽  
Parasitic Nematode ◽  
Prolonged Exposure ◽  
Brugia Malayi ◽  
Th2 Cells ◽  
Th2 Response ◽  
Antibody Isotypes ◽  
Ifn Γ ◽  
Higher Doses

Lymphatic filariasis caused by the parasitic nematode, Brugia malayi, is a chronic human disease immunologically characterized by stimulation of Th2 cells and reduced antigen-specific T cell responses. Single stage intra-peritoneal infections with infective larvae (L3) or adult nematodes induce Th2 cells, while the microfilarial stage (Mf) stimulates IFN-γ and Mf-specific IgG1, IgG2a, IgG2b, IgG3 and IgM, but not IgE. To investigate whether IFN-γ is elicited by live Mf in their natural site of infection, mice were infected intravenously. Intravenous infection had a striking effect on the response to Mf and high levels of IgE were induced even in the presence of IFN-γ. Indeed IgE levels to Mf increased markedly with the number of immunizations, higher doses of Mf and prolonged exposure to Mf suggesting that under conditions of chronic antigen exposure, typical of human disease, Mf will stimulate high levels of IgE. The ability of Mf-induced IFN-γ to modulate or regulate a pre-existing Th2 response, was investigated by infecting mice initially with adult male worms to induce a Th2 response, followed 14 days later by infection with Mf. Although Mf stimulated IFN-γ in the presence of male adults, the antibody isotypes elicited did not reflect IFN-γ induction and IgG1and IgE dominated the response. Although it cannot be discounted that IFN-γ induction by Mf may act locally as an inflammatory mediator or modulator of Th2 cells, these data suggest that Mf-stimulated IFN-γ does not have a profound effect overall on progression of the Th2-dominated immune response to filarial infection.

scholarly journals Tapeworm Infection Reduces Epithelial Ion Transport Abnormalities in Murine Dextran Sulfate Sodium-Induced Colitis

2001 ◽  
Vol 69 (7) ◽  
pp. 4417-4423 ◽  
Author(s):  
Colin Reardon ◽  
Ana Sanchez ◽  
Cory M. Hogaboam ◽  
Derek M. McKay
Keyword(s):  
Ion Transport ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Short Circuit ◽  
Hymenolepis Diminuta ◽  
Interleukin 12 ◽  
Free Access ◽  
Ussing Chambers ◽  
Epithelial Ion Transport ◽  
Ifn Γ

ABSTRACT The rat tapeworm Hymenolepis diminuta was used to test the hypothesis that helminth infection could modulate murine colitis. Mice were infected with five H. diminutacysticercoids, and colitis was evoked via free access to 4% (wt/vol) dextran sulfate sodium (DSS)-containing drinking water for 5 days. BALB/c mice were either infected with H. diminuta and 7 days later exposed to DSS (prophylactic strategy) or started on DSS and infected with H. diminuta 48 h later (treatment strategy). Naive andH. diminuta-only-infected mice served as controls. On autopsy, colonic segments were processed for histological examination and myeloperoxidase (MPO) measurement or mounted in Ussing chambers for assessment of epithelial ion transport. Cytokines (gamma interferon [IFN-γ], interleukin 12 [IL-12], and IL-10) were measured in serum and colonic tissue homogenates. DSS treatment resulted in reduced ion responses (indicated by short-circuit current [Isc]) to electrical nerve stimulation, the cholinergic agonist carbachol, and the adenylate cyclase activator forskolin compared to controls. H. diminuta infection, either prophylactic or therapeutic, caused a significant (P < 0.05) amelioration of these DSS-induced irregularities in stimulated ion transport. In contrast, the histopathology (i.e., mixed immune cell infiltrate, edema, and ulcerative damage) and elevated MPO levels that accompany DSS colitis were unaffected by concomitant H. diminuta infection. Similarly, there were no significant differences in levels of IFN-γ, IL-12, or IL-10 in serum or tissue from any of the treatment groups at the time of autopsy. We suggest that abolishment of colitis-induced epithelial ion transport abnormalities by H. diminuta infection provides proof-of-principle data and speculate that helminth therapy may provide relief of disease symptoms in colitis.

Superantigen immune stimulation activates epithelial STAT-1 and PI 3-K: PI 3-K regulation of permeability

2000 ◽  
Vol 279 (5) ◽  
pp. G1094-G1103 ◽  
Author(s):  
Derek M. McKay ◽  
Fernando Botelho ◽  
Peter J. M. Ceponis ◽  
Carl D. Richards
Keyword(s):  
Epithelial Cells ◽  
Conditioned Medium ◽  
Intracellular Signaling ◽  
Mononuclear Cells ◽  
Interferon Γ ◽  
Transepithelial Resistance ◽  
Mobility Shift ◽  
Peripheral Blood Mononuclear ◽  
Ussing Chambers ◽  
Ifn Γ

Signal transducers and activators of transcription (STATs) are critical intracellular signaling molecules for many cytokines. We compared the ability of T84 epithelial cells to activate STATs in response to cytokines [interferon-γ (IFN-γ), interleukin (IL)-4, IL-10, and tumor necrosis factor-α (10 ng/ml)] and conditioned medium from superantigen [ Staphylococcus aureus enterotoxin B (SEB)]-activated peripheral blood mononuclear cells (PBMC) using electrophoretic mobility shift assays (EMSA). Of the cytokines tested, only IFN-γ caused a STAT-1 response. Exposure to SEB-PBMC-conditioned medium resulted in STAT-1 or STAT-1/3 activation, and inclusion of anti-IFN-γ antibodies in the conditioned medium abolished the STAT-1 signal. Cells treated with transcription factor decoys, DNA oligonucleotides bearing the STAT-1 recognition motif, and then SEB-PBMC-conditioned medium displayed a reduced STAT-1 signal on EMSA, yet this treatment did not prevent the drop in transepithelial resistance (measured in Ussing chambers) caused by SEB-PBMC-conditioned medium. In contrast, the phosphatidylinositol 3′-kinase (PI 3-K) inhibitor LY-294002 significantly reduced the drop in transepithelial resistance caused by SEB-PBMC-conditioned medium. Thus data are presented showing STAT-1 (±STAT-3) and PI 3-K activation in epithelial cells in response to immune mediators released by superantigen immune activation. Although the involvement of STAT-1/-3 in the control of barrier function remains a possibility, PI-3K has been identified as a regulator of T84 paracellular permeability.

Role of NF-κB in β-cell death

2008 ◽  
Vol 36 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Danielle Melloul
Keyword(s):  
Cell Death ◽  
Lymphocytic Infiltration ◽  
Nuclear Factor Κb ◽  
Interferon Γ ◽  
Cell Protection ◽  
Β Cells ◽  
Β Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Apoptotic β-cell death appears to be central to the pathogenesis of Type 1 diabetes mellitus and in islet graft rejection. The β-cell destruction is partially mediated by cytokines, such as IL-1β (interleukin 1β), TNFα (tumour necrosis factor α) and IFN-γ (interferon γ). IL-1β and TNFα mediate activation of the transcription factor NF-κB (nuclear factor κB) pathway. Use of a degradation-resistant NF-κB protein inhibitor (ΔNIκBα), specifically expressed in β-cells, significantly reduced IL-1β+IFN-γ-induced apoptosis. Moreover, in vivo, it protected against multiple low-dose streptozocin-induced diabetes, with reduced intra-islet lymphocytic infiltration. Thus β-cell-specific activation of NF-κB is a key event in the progressive loss of β-cells in diabetes. Inhibition of this process could be a potential effective strategy for β-cell protection.

scholarly journals KIR reconstitution is altered by T cells in the graft and correlates with clinical outcomes after unrelated donor transplantation

Blood ◽  
2005 ◽  
Vol 106 (13) ◽  
pp. 4370-4376 ◽  
Author(s):  
Sarah Cooley ◽  
Valarie McCullar ◽  
Rosanna Wangen ◽  
Tracy L. Bergemann ◽  
Stephen Spellman ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Clinical Outcomes ◽  
Hematopoietic Cell Transplantation ◽  
Cell Function ◽  
Nk Cell ◽  
Interferon Γ ◽  
Unrelated Donor ◽  
Ifn Γ

Although unrelated hematopoietic cell transplantation (HCT) is curative for many hematologic malignancies, complications and relapse remain challenging obstacles. Natural killer (NK) cells, which recover quickly after transplantation, produce cytokines and express killer immunoglobulin-like receptors (KIRs) that regulate their cytotoxicity. Some clinical trials based on a KIR ligand mismatch strategy are associated with less relapse and increased survival, but results are mixed. We hypothesized that T cells in the graft may affect NK cell function and KIR expression after unrelated transplantation and that these differences correlate with clinical outcomes. NK cell function was evaluated using 77 paired samples from the National Marrow Donor Program Research Repository. Recipient NK cells at 100 days after both unmanipulated bone marrow (UBM) and T-cell depleted (TCD) transplants were compared with NK cells from their healthy donors. NK cells expressed fewer KIRs and produced more interferon γ (IFN-γ) after UBM compared to TCD transplants. Multivariate models showed that increased NK cell IFN-γ production correlated with more acute graft-versus-host disease (GVHD), and decreased KIR expression correlated with inferior survival. These results support the notion that T cells in the graft affect NK cell reconstitution in vivo. Understanding these mechanisms may result in strategies to improve clinical outcomes from unrelated HCT.

scholarly journals Synergistic interactions between interferon-γ and TRAIL modulate c-FLIP in endothelial cells, mediating their lineage-specific sensitivity to thrombotic thrombocytopenic purpura plasma–associated apoptosis

Blood ◽  
2008 ◽  
Vol 112 (2) ◽  
pp. 340-349 ◽  
Author(s):  
Radu Stefanescu ◽  
Dustin Bassett ◽  
Rozbeh Modarresi ◽  
Francisco Santiago ◽  
Mohamad Fakruddin ◽  
...  
Keyword(s):  
Thrombotic Thrombocytopenic Purpura ◽  
Interferon Γ ◽  
Microvascular Endothelial Cell ◽  
Caspase 8 ◽  
Inhibitory Protein ◽  
Thrombocytopenic Purpura ◽  
Ifn Γ ◽  
Interfering Rna

Abstract Microvascular endothelial cell (MVEC) injury coupled to progression of platelet microthrombi facilitated by ADAMTS13 deficiency is characteristic of idiopathic and HIV-linked thrombotic thrombocytopenic purpura (TTP). Cytokines capable of inducing MVEC apoptosis in vitro are up-regulated in both TTP and HIV infection. However, the concentrations of these cytokines required to elicit EC apoptosis in vitro are 2- to 3-log–fold greater than present in patient plasmas. We report that clinically relevant levels of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and interferon (IFN)–γ act in synergy to induce apoptosis in dermal MVECs, but have no effect on large-vessel ECs or pulmonary MVECs. This reflects the tissue distribution of TTP lesions in vivo. Sensitivity to TTP plasma or TRAIL plus IFN-γ is paralleled by enhanced ubiquitination of the caspase-8 regulator cellular FLICE-like inhibitory protein (c-FLIP), targeting it for proteasome degradation. c-FLIP silencing with anti-FLIP short interfering RNA (siRNA) in pulmonary MVECs rendered them susceptible to TTP plasma– and cytokine-mediated apoptosis, while up-regulation of c-FLIP by gene transfer partially protected dermal MVECs from such injury. TTP plasma–mediated apoptosis appears to involve cytokine-induced acceleration of c-FLIP degradation, sensitizing cells to TRAIL-mediated caspase-8 activation and cell death. Suppression of TRAIL or modulation of immunoproteasome activity may have therapeutic relevance in TTP.

Effects of the Japanese herbal medicine ‘Inchinko-to’ (TJ-135) on concanavalin A-induced hepatitis in mice

2000 ◽  
Vol 99 (5) ◽  
pp. 421-431 ◽  
Author(s):  
Masayoshi YAMASHIKI ◽  
Akihito MASE ◽  
Ichiro ARAI ◽  
Xian-Xi HUANG ◽  
Tsutomu NOBORI ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Concanavalin A ◽  
Serum Levels ◽  
Interferon Γ ◽  
Hepatic Necrosis ◽  
Interleukin 12 ◽  
Con A ◽  
Ifn Γ

Inchinko-to (TJ-135) is a herbal medicine consisting of three kinds of crude drugs, and in Japan it is administered mainly to patients with cholestasis. The present study evaluated the effects of TJ-135 on concanavalin A (con A)-induced hepatitis in mice in vivo and con A-induced cytokine production in vitro. When mice were pretreated with oral TJ-135 for 1 week before intravenous con A injection, the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly decreased 8 h after con A administration (-82%, -96% and -66% respectively). In histological investigations, sub-massive hepatic necrosis accompanying inflammatory cell infiltration was not observed in mice pretreated with TJ-135. Serum levels of interleukin-12 (IL-12), interferon-γ (IFN-γ) and IL-2 were significantly lower in mice pretreated with TJ-135 compared with controls, while IL-10 levels were higher in these mice. Intrasplenic IL-12 levels were significantly lower in mice pretreated with TJ-135, while intrasplenic IL-10 levels were higher in these mice. In vitro, IL-10 production by splenocytes was increased by the addition of TJ-135 to the culture medium, whereas the production of IL-12 and IFN-γ was inhibited. These results suggest that con A-induced hepatitis was ameliorated by pretreatment with TJ-135. With regard to the mechanism of these effects of TJ-135, we speculate that TJ-135 inhibits the production of inflammatory cytokine and enhances the production of anti-inflammatory cytokines. Therefore administration of TJ-135 may be useful in patients with severe acute hepatitis accompanying cholestasis or in those with autoimmune hepatitis.

scholarly journals Human-derived probiotic Lactobacillus reuteri strains differentially reduce intestinal inflammation

2010 ◽  
Vol 299 (5) ◽  
pp. G1087-G1096 ◽  
Author(s):  
Yuying Liu ◽  
Nicole Y. Fatheree ◽  
Nisha Mangalat ◽  
Jon Marc Rhoads
Keyword(s):  
Lactobacillus Reuteri ◽  
Intestinal Inflammation ◽  
Cow Milk ◽  
Intestinal Cells ◽  
Milk Formula ◽  
Mrna Levels ◽  
Newborn Rat ◽  
Rat Pups ◽  
Ifn Γ

Lactobacillus reuteri ( L. reuteri ) is a probiotic that inhibits the severity of enteric infections and modulates the immune system. Human-derived L. reuteri strains DSM17938, ATCC PTA4659, ATCC PTA 5289, and ATCC PTA 6475 have demonstrated strain-specific immunomodulation in cultured monocytoid cells, but information about how these strains affect inflammation in intestinal epithelium is limited. We determined the effects of the four different L. reuteri strains on lipopolysaccharide (LPS)-induced inflammation in small intestinal epithelial cells and in the ileum of newborn rats. IPEC-J2 cells (derived from the jejunal epithelium of a neonatal piglet) and IEC-6 cells (derived from the rat crypt) were treated with L. reuteri . Newborn rat pups were gavaged cow milk formula supplemented with L. reuteri strains in the presence or absence of LPS. Protein and mRNA levels of cytokines and histological changes were measured. We demonstrate that even though one L. reuteri strain (DSM 17938) did not inhibit LPS-induced IL-8 production in cultured intestinal cells, all strains significantly reduced intestinal mucosal levels of KC/GRO (∼IL-8) and IFN-γ when newborn rat pups were fed formula containing LPS ± L. reuteri . Intestinal histological damage produced by LPS plus cow milk formula was also significantly reduced by all four strains. Cow milk formula feeding (without LPS) produced mild gut inflammation, evidenced by elevated mucosal IFN-γ and IL-13 levels, a process that could be suppressed by strain 17938. Other cytokines and chemokines were variably affected by the different strains, and there was no toxic effect of L. reuteri on intestinal cells or mucosa. In conclusion, L. reuteri strains differentially modulate LPS-induced inflammation. Probiotic interactions with both epithelial and nonepithelial cells in vivo must be instrumental in modulating intrinsic anti-inflammatory effects in the intestine. We suggest that the terms anti- and proinflammatory be used only to describe the effects of a probiotic in the living host.

Sign in / Sign up

Export Citation Format

Share Document