Activation of purinergic P2Y2 receptors inhibits inducible NO synthase in cultured rat mesangial cells

1998 ◽  
Vol 275 (1) ◽  
pp. F103-F110 ◽  
Author(s):  
Markus G. Mohaupt ◽  
Tina Fischer ◽  
Jörg Schwöbel ◽  
R. Bernd Sterzel ◽  
Eckhard Schulze-Lohoff
Keyword(s):  
Mesangial Cells ◽  
Critical Role ◽  
Inhibitory Effect ◽  
Interferon Γ ◽  
Glomerular Injury ◽  
Inos Protein ◽  
P2y2 Receptors ◽  
Nitrite Production ◽  
Inos Protein Expression ◽  
Ifn Γ

Cytokine-induced nitric oxide (NO) is produced on glomerular inflammation. Glomerular injury and thrombocyte aggregation result in the release of nucleotides, which may regulate induced NO synthesis in cultured rat mesangial cells (MCs). ATP (10−3 M) inhibited 24-h nitrite production induced by lipopolysaccharide (LPS, 10 μg/ml)/interferon-γ (IFN-γ, 100 U/ml) by 48.2 ± 6.3%, as well as induction of inducible NOS (iNOS) protein and mRNA. Also, coincubation with either 10−4 M of UTP, ATP, or ATPγS inhibited LPS/IFN-γ-induced nitrite production by 29.9 ± 5.8, 36.4 ± 4.3, and 50.3 ± 6.5%, respectively, indicating involvement of purinergic P2Y2 receptors. Correspondingly, cultured MCs expressed P2Y2 receptor mRNA. Agonists for other purinergic receptors [α,β-methylene-ATP, 3′- O-(4-benzoyl)-benzoyl-ATP, 2-methylthio-ATP, ADP, UDP, adenosine] were ineffective. Treatment with the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA, 10−8 M) reproduced the inhibitory effect of ATP on iNOS protein expression and nitrite inhibition (by 46.6 ± 10.4%). The effect of ATP or PMA was reversed by the PKC inhibitors Ro-31-8220 (10−8 M) and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (10−5 M), indicating that suppression of iNOS is mediated via activation of PKC through stimulated P2Y2 receptors. In conclusion, the release of purine mediators may play a critical role for iNOS expression and synthesis of NO during glomerular inflammatory disorders.

IFN-γ + LPS induction of iNOS is modulated by ERK, JNK/SAPK, and p38 mapk in a mouse macrophage cell line

2001 ◽  
Vol 280 (3) ◽  
pp. C441-C450 ◽  
Author(s):  
Edward D. Chan ◽  
David W. H. Riches
Keyword(s):  
Nitric Oxide ◽  
Cell Line ◽  
Inhibitory Effect ◽  
Interferon Γ ◽  
Dominant Negative ◽  
Jnk Pathway ◽  
Mutant Proteins ◽  
Inos Promoter ◽  
Ifn Γ ◽  
Inos Induction

Nitric oxide (NO·) produced by inducible nitric oxide synthase (iNOS) mediates a number of important physiological and pathophysiological processes. The objective of this investigation was to examine the role of mitogen-activated protein kinases (MAPKs) in the regulation of iNOS and NO· by interferon-γ (IFN-γ) + lipopolysaccharide (LPS) in macrophages using specific inhibitors and dominant inhibitory mutant proteins of the MAPK pathways. The signaling pathway utilized by IFN-γ in iNOS induction is well elucidated. To study signaling pathways that are restricted to the LPS-signaling arm, we used a subclone of the parental RAW 264.7 cell line that is unresponsive to IFN-γ alone with respect to iNOS induction. In this RAW 264.7γNO(−) subclone, IFN-γ and LPS are nevertheless required for synergistic activation of the iNOS promoter. We found that extracellular signal-regulated kinase (ERK) augmented and p38 mapk inhibited IFN-γ + LPS induction of iNOS. Dominant-negative MAPK kinase-4 inhibited iNOS promoter activation by IFN-γ + LPS, also implicating the c-Jun NH2-terminal kinase (JNK) pathway in mediating iNOS induction. Inhibition of the ERK pathway markedly reduced IFN-γ + LPS-induced tumor necrosis factor-α protein expression, providing a possible mechanism by which ERK augments iNOS expression. The inhibitory effect of p38 mapk appears more complex and may be due to the ability of p38 mapk to inhibit LPS-induced JNK activation. These results indicate that the MAPKs are important regulators of iNOS-NO· expression by IFN-γ + LPS.

scholarly journals Spontaneous secretion of interferon γ and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes

Gut ◽  
1998 ◽  
Vol 42 (5) ◽  
pp. 643-649 ◽  
Author(s):  
M Carol ◽  
A Lambrechts ◽  
A Van Gossum ◽  
M Libin ◽  
M Goldman ◽  
...  
Keyword(s):  
Lamina Propria ◽  
Intestinal Mucosa ◽  
Mononuclear Cells ◽  
Critical Role ◽  
Gastrointestinal Diseases ◽  
Interferon Γ ◽  
Interleukin 4 ◽  
Peripheral Blood Mononuclear ◽  
Ifn Γ

Background—Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses.Aims—To quantify interferon γ (IFN-γ) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation.Patients—Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa.Methods—Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-γ and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT).Results—The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-γ (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-γ SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-γ and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-γ in the basal state, and 0.1% secreted IL-4.Conclusions—Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-γ and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.

scholarly journals CD16+ monocytes control T-cell subset development in immune thrombocytopenia

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3326-3335 ◽  
Author(s):  
Hui Zhong ◽  
Weili Bao ◽  
Xiaojuan Li ◽  
Allison Miller ◽  
Caroline Seery ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Thrombocytopenia ◽  
Critical Role ◽  
Cell Subset ◽  
Inhibitory Effect ◽  
Cell Polarization ◽  
T Cell Subsets ◽  
Monocyte Subset ◽  
Th Cells ◽  
Ifn Γ

Abstract Immune thrombocytopenia (ITP) results from decreased platelet production and accelerated platelet destruction. Impaired CD4+ regulatory T-cell (Treg) compartment and skewed Th1 and possibly Th17 responses have been described in ITP patients. The trigger for aberrant T-cell polarization remains unknown. Because monocytes have a critical role in development and polarization of T-cell subsets, we explored the contribution of monocyte subsets in control of Treg and Th development in patients with ITP. Unlike circulating classic CD14hiCD16− subpopulation, the CD16+ monocyte subset was expanded in ITP patients with low platelet counts on thrombopoietic agents and positively correlated with T-cell CD4+IFN-γ+ levels, but negatively with circulating CD4+CD25hiFoxp3+ and IL-17+ Th cells. Using a coculture model, we found that CD16+ ITP monocytes promoted the expansion of IFN-γ+CD4+ cells and concomitantly inhibited the proliferation of Tregs and IL-17+ Th cells. Th-1–polarizing cytokine IL-12, secreted after direct contact of patient T-cell and CD16+ monocytes, was responsible for the inhibitory effect on Treg and IL-17+CD4+ cell proliferation. Our findings are consistent with ITP CD16+ monocytes promoting Th1 development, which in turn negatively regulates IL-17 and Treg induction. This underscores the critical role of CD16+ monocytes in the generation of potentially pathogenic Th responses in ITP.

scholarly journals Inactivation of the Fanconi Anemia Group C Gene Augments Interferon-γ–Induced Apoptotic Responses in Hematopoietic Cells

Blood ◽  
1997 ◽  
Vol 90 (3) ◽  
pp. 974-985 ◽  
Author(s):  
R. Keaney Rathbun ◽  
Gregory R. Faulkner ◽  
Marika H. Ostroski ◽  
Tracy A. Christianson ◽  
Grant Hughes ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Inhibitory Effect ◽  
Interferon Γ ◽  
Interferon Response ◽  
Low Doses ◽  
Order Of Magnitude ◽  
Ifn Γ ◽  
Fas Pathway ◽  
Anemia Group ◽  
Induced Apoptosis

Abstract Hematopoietic progenitor cells (HPC) from mice nullizygous at the Fanconi anemia (FA) group C locus (FAC −/−) are hypersensitive to the mitotic inhibitory effects of interferon (IFN-γ). We tested the hypothesis that HPC from the bone marrow of Fanconi group C children are similarly hypersensitive and that the fas pathway is involved in affecting programmed cell death in response to low doses of IFN-γ. In normal human and murine HPC, IFN-γ primed the fas pathway and induced both fas and interferon response factor-1 (IRF-1) gene expression. These IFN-γ-induced apoptotic responses in HPC from the marrow of a child with FA of the C group (FA-C) and in FAC −/− mice occurred at significantly lower IFN doses (by an order of magnitude) than did the apoptotic responses of normal HPC. Treatment of FA-C CD34+ cells with low doses of recombinant IFN-γ, inhibited growth of colony forming unit granulocyte-macrophage and burst-forming unit erythroid, while treatment with blocking antibodies to fas augmented clonal growth and abrogated the clonal inhibitory effect of IFN-γ. Transfer of the normal FAC gene into FA-C B-cell lines prevented mitomycin C–induced apoptosis, but did not suppress fas expression or inhibit the primed fas pathway. However, the kinetics of Stat1-phosphate decay in IFN-γ–treated cells was prolonged in mutant cells and was normalized by transduction of the normal FAC gene. Therefore, the normal FAC protein serves, in part, to modulate IFN-γ signals. HPC bearing inactivating mutations of FAC fail to normally modulate IFN-γ signals and, as a result, undergo apoptosis executed through the fas pathway.

Mesenchymal stromal cell plasticity and the tumor microenvironment

2017 ◽  
Vol 1 (5) ◽  
pp. 487-492
Author(s):  
Hee Joon Bae ◽  
Shutong Liu ◽  
Ping Jin ◽  
David Stroncek
Keyword(s):  
Tumor Microenvironment ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Tumor Infiltrating Lymphocytes ◽  
Transforming Growth Factor Β ◽  
Interferon Γ ◽  
Tnf Α ◽  
Ifn Γ ◽  
Factor Α ◽  
Infiltrating Lymphocytes

Mesenchymal stem cells or mesenchymal stromal cells (MSCs) are a multipotent, heterogeneous population of cells that play a critical role in wound healing and tissue regeneration. MSCs, found in the tumor microenvironment, support tumor growth through the production of angiogenic factors, growth factors and extracellular matrix proteins. They also have immunomodulatory properties, and since they produce indoleamine 2,3-dioxygenase (IDO), prostaglandin E2 (PGE2) and transforming growth factor β (TGF-β), they have been thought to have primarily immunosuppressive effects. However, their role in the tumor microenvironment is complex and demonstrates plasticity depending on location, stimulatory factors and environment. The presence of melanoma-activated tumor-infiltrating lymphocytes (TILs) has been shown to produce pro-inflammatory changes with TH1 (type 1T helper)-like phenotype in MSCs via activated-TIL released cytokines such as interferon γ (IFN-γ), tumor necrosis factor α (TNF-α) and interleukin-1α (IL-1α), while simultaneously producing factors, such as IDO1, which have been traditionally associated with immunosuppression. Similarly, the combination of IFN-γ and TNF-α polarizes MSCs to a primarily TH1-like phenotype with the expression of immunosuppressive factors. Ultimately, further studies are encouraged and needed for a greater understanding of the role of MSCs in the tumor microenvironment and to improve cancer immunotherapy.

scholarly journals Atypical Disease after Bordetella pertussis Respiratory Infection of Mice with Targeted Disruptions of Interferon-γ Receptor or Immunoglobulin μ Chain Genes

1997 ◽  
Vol 186 (11) ◽  
pp. 1843-1851 ◽  
Author(s):  
Bernard P. Mahon ◽  
Brian J. Sheahan ◽  
Fiona Griffin ◽  
Geraldine Murphy ◽  
Kingston H.G. Mills
Keyword(s):  
Respiratory Infection ◽  
Bordetella Pertussis ◽  
Critical Role ◽  
Interferon Γ ◽  
Th2 Cells ◽  
Natural Immunity ◽  
Mesenteric Lymph Nodes ◽  
Ifn Γ ◽  
Respiratory Challenge ◽  
Disseminated Disease

Using a murine respiratory challenge model we have previously demonstrated a role for Th1 cells in natural immunity against Bordetella pertussis, but could not rule out a role for antibody. Here we have demonstrated that B. pertussis respiratory infection of mice with targeted disruptions of the genes for the IFN-γ receptor resulted in an atypical disseminated disease which was lethal in a proportion of animals, and was characterized by pyogranulomatous inflammation and postnecrotic scarring in the livers, mesenteric lymph nodes and kidneys. Viable virulent bacteria were detected in the blood and livers of diseased animals. An examination of the course of infection in the lung of IFN-γ receptor–deficient, IL-4–deficient and wild-type mice demonstrated that lack of functional IFN-γ or IL-4, cytokines that are considered to play major roles in regulating the development of Th1 and Th2 cells, respectively, did not affect the kinetics of bacterial elimination from the lung. In contrast, B cell–deficient mice developed a persistent infection and failed to clear the bacteria after aerosol inoculation. These findings demonstrate an absolute requirement for B cells or their products in the resolution of a primary infection with B. pertussis, but also define a critical role for IFN-γ in containing bacteria to the mucosal site of infection.

scholarly journals A Critical Role for Interleukin 18 in Primary and Memory Effector Responses to Listeria monocytogenes That Extends Beyond Its Effects on Interferon γ Production

2001 ◽  
Vol 194 (3) ◽  
pp. 343-354 ◽  
Author(s):  
Margaret Neighbors ◽  
Xiuling Xu ◽  
Franck J. Barrat ◽  
Sigrid R. Ruuls ◽  
Tatyana Churakova ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Critical Role ◽  
Interferon Γ ◽  
T Helper ◽  
Protective Capacity ◽  
Major Player ◽  
Ifn Γ ◽  
Listeria Infection ◽  
Th 1 ◽  
Necrosis Factor

The stimulation of interferon (IFN)-γ by interleukin (IL)-12 has been shown to provide protection from intracellular pathogens such as Listeria monocytogenes. Tumor necrosis factor (TNF) is also a major player in the resolution of Listeria infections and is suggested to have more global effects than can be explained by the induction of IFN-γ alone. Since IL-18 synergizes with IL-12 to induce IFN-γ production by natural killer and T helper (Th)1 cells, we determined its role in responses to Listeria. IL-18 appeared to be even more potent than either IL-12 or IFN-γ for protection against this pathogen and IL-18 enhanced bacterial clearance in the complete absence of IFN-γ. Indeed IL-18 was comparable to TNF in its ability to resolve the infection and showed a lowered protective capacity in the absence of TNF. Moreover, IL-18 induced macrophages to secrete both TNF and nitric oxide after a Listeria infection. IL-18 was also essential for optimal IFN-γ production by antigen-specific T cells. Therefore, IL-18 operates via its effects on both the innate immune response, including macrophages, as well as on Th1 cells, to protect against Listeria.

scholarly journals Interferon γ Stabilizes the T Helper Cell Type 1 Phenotype

2001 ◽  
Vol 194 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Yongkang Zhang ◽  
Ron Apilado ◽  
John Coleman ◽  
Shlomo Ben-Sasson ◽  
Sharon Tsang ◽  
...  
Keyword(s):  
Critical Role ◽  
Interferon Γ ◽  
T Helper Cell ◽  
Helper Cell ◽  
Wild Type ◽  
T Helper ◽  
Helper Cell Type ◽  
Ifn Γ ◽  
Th 1

T helper cell (Th)1-primed CD4 T cells from wild-type donors make little interleukin (IL)-4 when restimulated under Th2 conditions. However, such restimulation of Th1-primed cells from interferon (IFN)-γ2/− or IFN-γ receptor (IFN-γR)−/− mice resulted in substantial production of IL-4 and other Th2 cytokines. Adding IFN-γ to the priming culture markedly diminished the capacity of Th1-primed IFN-γ2/− cells to express IL-4. Even IFN-γ–producing cells from IFN-γR−/− mice could acquire IL-4–producing capacity. Thus, IFN-γ is not required for the development of IFN-γ–producing capacity, but it plays a critical role in suppressing the IL-4–producing potential of Th1 cells.

Hydrogen peroxide downregulates IL-1-driven mesangial iNOS activity: implications for glomerulonephritis

1997 ◽  
Vol 272 (6) ◽  
pp. F721-F728 ◽  
Author(s):  
E. A. Jaimes ◽  
K. A. Nath ◽  
L. Raij
Keyword(s):  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Mesangial Cells ◽  
Interleukin 1 ◽  
Inhibitory Effect ◽  
Inos Mrna ◽  
No Production ◽  
Glomerular Injury ◽  
Inos Activity ◽  
Oxide Synthase

In glomerulonephritides, autacoids such as nitric oxide (NO), reactive oxygen species, and prostanoids are produced in increased amounts in response to cytokines such as interleukin-1 (IL-1). These autacoids influence the expression of glomerular injury by their direct as well as interactive actions. We studied the effect of hydrogen peroxide (H2O2) on NO production in rat mesangial cells. We demonstrate that transient exposure of mesangial cells to H2O2 prior to sustained exposure to IL-1 decreased extracellular accumulation of NO2/NO3 and cellular guanosine 3,'5'-cyclic monophosphate (cGMP) content. H2O2 markedly impaired inducible nitric oxide synthase (iNOS) activity induced by IL-1 directly measured by the conversion of L-[14C]arginine to L-[14C]citrulline. Such impairment in iNOS activity was accompanied by a parallel reduction in iNOS protein abundance but not by a reduced expression of iNOS mRNA. The inhibitory effect of H2O2 on NOS activity was further supported by peroxide-induced impairment in IL-1-driven, NO-dependent synthesis of prostaglandin E2. Our studies thus provide the first direct evidence of a posttranscriptional inhibitory effect of H2O2 on iNOS activity. Additionally, our studies uncover the existence of a previously unrecognized effect of H2O2 on the production of NO that may exert influence on the severity of glomerular injury during glomerular inflammation.

Acute stressor exposure both suppresses acquired immunity and potentiates innate immunity

1998 ◽  
Vol 275 (3) ◽  
pp. R870-R878 ◽  
Author(s):  
Monika Fleshner ◽  
Kien T. Nguyen ◽  
Crystal S. Cotter ◽  
Linda R. Watkins ◽  
Steven F. Maier
Keyword(s):  
Keyhole Limpet Hemocyanin ◽  
Interferon Γ ◽  
Cell Number ◽  
Antigenic Protein ◽  
Nitrite Production ◽  
Ifn Γ ◽  
Cell Subpopulations ◽  
T Cell Subpopulations ◽  
Acute Stressor ◽  
Increase Cell Number

Acute stressor exposure alters immune function. Rats exposed to inescapable tail shock stress (IS) generate less antibody to a benign, antigenic protein, keyhole limpet hemocyanin (KLH). The following studies examined the effect of IS on peritoneal cavity, spleen, and mesenteric lymph node cell number, interferon-γ (IFN-γ) production, and nitrite production. Rats were injected intraperitoneally with KLH (200 μg) or saline immediately before IS exposure and killed 0, 48, and 96 h after IS termination. KLH immunization resulted in elevated cell numbers and IFN-γ levels 2–4 days later in nonstressed control rats. In contrast, rats exposed to IS failed to increase cell number and IFN-γ levels in response to KLH. The T cell subpopulations affected were CD4 T cells, specifically the Th1-like subset. In addition, in rats exposed to IS + KLH, nitrite production was potentiated 2–4 days after stressor termination. IS had little effect on these measures in saline-injected rats. These data support the conclusion that exposure to IS suppresses the expansion of anti-KLH lymphocytes, possibly anti-KLH Th1 cells. In addition, stressor exposure potentiates the production of nitrite. Importantly, this potentiated response occurred only in KLH-immunized animals, suggesting that macrophages may be primed by stressor exposure and thus respond more vigorously to antigen. The potential links between these changes are discussed.

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