scholarly journals Activation of autophagy reverses gemcitabine-induced immune inhibition of RAW264.7 macrophages by promoting TNF-α, IL-6 and MHC-II expression

Author(s):  
Shanshan Jiang ◽  
Rong Wang ◽  
Lu Han ◽  
Kudelaidi Kuerban ◽  
Li Ye ◽  
...  

AbstractThis research aims to investigate the effect of gemcitabine (GEM) on various activities and functions of macrophages. Phagocytosis, cell autophagy and reactive oxygen species (ROS) were analysed by laser scanning confocal microscope. The cell cycle status and major histocompatibility complex II (MHC-II) expression were examined by flow cytometry. Inflammatory cytokine secretion such as tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) was detected by Elisa assay. The expression of proteins was analysed by western blot method. The results revealed that GEM-induced immune inhibition of M1-type RAW264.7 macrophages activated by interferon-γ (IFN-γ) and lipopolysaccharide (LPS). We also found that GEM inhibited autophagy, as evidenced by the reduced formation of autophagosome-like vacuoles and autophagosomes. Further study showed that incubation of activated macrophages with the autophagy inhibitor 3-MA induced immune suppression. In contrast, treatment with the autophagy inducer trehalose (Tre) restored phagocytosis, TNF-α and IL-6 secretion, and MHC-II expression in GEM-induced immune-inhibited macrophages. GEM reduced immune effect of M1-type RAW264.7 macrophages via inhibiting TNF-α, IL-6 and MHC-II expression. Furthermore, activation of autophagy by Tre reversed GEM-induced immune inhibition of RAW264.7 macrophages.

2004 ◽  
Vol 3 (2) ◽  
pp. 24-29
Author(s):  
Ye. Yu. Sherstoboyev ◽  
O. A. Kaplya ◽  
Ye. P. Zuyeva ◽  
T. G. Razina ◽  
O. I. Epstein

Cytokine production by cell-effectors of natural cytotoxicity system under Lewis lung carcinoma development in F1(CBAxC57B1/6) line mice has been studied. It has been revealed the increase of interleukin-1β (IL-1β) production and tumor necrosis factor-α (TNF-α) by peritoneal macrophages. At this the balance of cytokines produced by T-helpers (Th)  has  been displaced to Th2 side, IL-4 production has increased and interferon-γ (IFN-γ) and IL-2 production has decreased. The rise of IL-10 production by lymphocytes has been observed in the later terms of tumor development.


Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 582 ◽  
Author(s):  
Yuan ◽  
Zhang ◽  
Shen ◽  
Jia ◽  
Xie

Phytosterols, found in many commonly consumed foods, exhibit a broad range of physiological activities including anti-inflammatory effects. In this study, the anti-inflammatory effects of ergosterol, β-sitosterol, stigmasterol, campesterol, and ergosterol acetate were investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Results showed that all phytosterol compounds alleviated the inflammatory reaction in LPS-induced macrophage models; cell phagocytosis, nitric oxide (NO) production, release of tumor necrosis factor-α (TNF-α), and expression and activity of pro-inflammatory mediator cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and phosphorylated extracellular signal-regulated protein kinase (p-ERK) were all inhibited. The anti-inflammatory activity of β-sitosterol was higher than stigmasterol and campesterol, which suggests that phytosterols without a double bond on C-22 and with ethyl on C-24 were more effective. However, inconsistent results were observed upon comparison of ergosterol and ergosterol acetate (hydroxy or ester group on C-3), which suggest that additional research is still needed to ascertain the contribution of structure to their anti-inflammatory effects.


1999 ◽  
Vol 276 (4) ◽  
pp. C892-C899 ◽  
Author(s):  
Joseph Satriano ◽  
Shunji Ishizuka ◽  
D. Clay Archer ◽  
Roland C. Blantz ◽  
Carolyn J. Kelly

Nitric oxide (NO) has been described to exert cytostatic effects on cellular proliferation; however the mechanisms responsible for these effects have yet to be fully resolved. Polyamines, conversely, are required components of cellular proliferation. In experimental models of inflammation, a relationship between these two pathways has been suggested by the temporal regulation of a common precursor, arginine. This study was undertaken to determine the effects NO and the NO synthase (NOS)-inducing cytokines, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), exert on polyamine regulation. The transformed kidney proximal tubule cell line, MCT, maintains high constitutive levels of the first polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). NO donors markedly suppressed ODC activity in MCT and all other cell lines examined. TNF-α and IFN-γ induction of NO generation resulted in suppressed ODC activity, an effect prevented by the inducible NOS inhibitorl- N 6-(1-iminoethyl)lysine (l-NIL). Dithiothreitol reversal of NO-mediated ODC suppression supports nitrosylation as the mechanism of inactivation. We also evaluated polyamine uptake, inasmuch as inhibition of ODC can result in a compensatory induction of polyamine transporters. Administration of NO donors, or TNF-α and IFN-γ, suppressed [3H]putrescine uptake, thereby preventing transport-mediated reestablishment of intracellular polyamine levels. This study demonstrates the capacity of NO and inflammatory cytokines to regulate both polyamine biosynthesis and transport.


2017 ◽  
Vol 1 (5) ◽  
pp. 487-492
Author(s):  
Hee Joon Bae ◽  
Shutong Liu ◽  
Ping Jin ◽  
David Stroncek

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.


1997 ◽  
Vol 185 (7) ◽  
pp. 1231-1240 ◽  
Author(s):  
Alice P. Taylor ◽  
Henry W. Murray

Despite permitting uncontrolled intracellular visceral infection for 8 wk, interferon-γ (IFN-γ) gene knockout (GKO) mice infected with Leishmania donovani proceeded to reduce liver parasite burdens by 50% by week 12. This late-developing IFN-γ–independent antileishmanial mechanism appeared to be dependent largely on endogenous tumor necrosis factor-α (TNF-α): L. donovani infection induced TNF-α mRNA expression in parasitized GKO livers and neutralization of TNF-α reversed control at week 12. 7 d of treatment of infected GKO mice with interleukin-12 (IL-12) readily induced leishmanicidal activity and also partially restored the near-absent tissue granulomatous response, observations that for the first time expand the antimicrobial repertoire of IL-12 to include IFN-γ–independent effects. The action of IL-12 against L. donovani was TNF-α dependent and required the activity of inducible nitric oxide synthase. These results point to the presence of an IFN-γ–independent antimicrobial mechanism, mediated by TNF-α, which remains quiescent until activated late in the course of experimental visceral leishmaniasis. However, as judged by the effect of exogenous IL-12 this quiescent mechanism can readily be induced to rapidly yield enhanced intracellular antimicrobial activity.


Blood ◽  
2003 ◽  
Vol 102 (8) ◽  
pp. 2877-2884 ◽  
Author(s):  
Alison Smith ◽  
Fabio Santoro ◽  
Giulia Di Lullo ◽  
Lorenzo Dagna ◽  
Alessia Verani ◽  
...  

Abstract Human herpesvirus 6 (HHV-6) is a potentially immunosuppressive agent that has been suggested to act as a cofactor in the progression of HIV disease. Exposure of human macrophages to HHV-6A or HHV-6B profoundly impaired their ability to produce interleukin 12 (IL-12) upon stimulation with interferon-γ (IFN-γ) and lipopolysaccharide (LPS). By contrast, the production of tumor necrosis factor–α (TNF-α); regulated on activation, normal T-cell expressed and secreted (RANTES); and macrophage inflammatory protein 1β (MIP-1β) was not negatively affected. To exclude the involvement of IL-12–suppressive cytokines, such as IL-10 and TNF-α, the viral stocks were fractionated by ultra-centrifugation. The bulk of the suppressive activity was recovered within the virion-rich pelleted fraction that was virtually devoid of such cytokines. IL-12 suppression was independent of viral replication, and the effect was not abrogated upon ultraviolet-light inactivation of the viral inoculum. The mechanism of HHV-6–mediated IL-12 suppression was investigated by RNase protection assays, which demonstrated unaltered levels of IL-12 p35 mRNA and only a modest reduction in p40 mRNA, which was insufficient to account for the near-complete loss of both extracellular and intracellular IL-12 protein. Moreover, both the IFN-γ and the LPS signaling pathways were intact in HHV-6–treated cells. These data suggest that HHV-6 can dramatically affect the generation of effective cellular immune responses, providing a novel potential mechanism of HHV-6–mediated immunosuppression.


2012 ◽  
Vol 39 (5) ◽  
pp. 979-985 ◽  
Author(s):  
ALESSANDRO ANTONELLI ◽  
POUPAK FALLAHI ◽  
SILVIA MARTINA FERRARI ◽  
DILIA GIUGGIOLI ◽  
MICHELE COLACI ◽  
...  

Objective.We evaluated the effect of interferon-γ (IFN-γ) and/or tumor necrosis factor-α (TNF-α) on the secretion of prototype proinflammatory cytokine interleukin 6 (IL-6), compared to T-helper 1 [Th1; chemokine (C-X-C motif) ligand 10 (CXCL10)] or Th2 [chemokine (C-C motif) ligand 2 (CCL2)] chemokines, in primary cultured fibroblasts from patients with systemic sclerosis (SSc) at an early stage of the disease.Methods.Fibroblast cultures from 5 SSc patients (disease duration < 2 yrs) and 5 healthy controls were evaluated for the production of IL-6, CXCL10, and CCL2 at the basal level and after stimulation with IFN-γ and/or TNF-α.Results.SSc fibroblasts basally produced higher levels of IL-6 than controls, while no difference was observed about CCL2 and CXCL10. TNF-α was able to dose-dependently induce IL-6 and CCL2 secretion in SSc, but not in control fibroblasts. By stimulation with increasing doses of IFN-γ, SSc fibroblasts were induced to secrete CCL2 and CXCL10, while no effect was observed on IL-6. The combination of IFN-γ and TNF-α induced a strong secretion of IL-6 and CCL2 in SSc fibroblasts but not in controls. In contrast, the synergistic effect of IFN-γ and TNF-α on CXCL10 secretion was similar in SSc fibroblasts and in controls.Conclusion.SSc fibroblasts participate in the self-perpetuation of inflammation by releasing IL-6, CXCL10, and CCL2 under the influence of IFN-γ and/or TNF-α. SSc fibroblasts are more active than controls in the secretion of IL-6 at baseline, and in the production of IL-6 and CCL2 under the combined IFN-γ/TNF-α stimulation.


2008 ◽  
Vol 295 (5) ◽  
pp. C1191-C1201 ◽  
Author(s):  
Olga J. Baker ◽  
Jean M. Camden ◽  
Robert S. Redman ◽  
Jonathan E. Jones ◽  
Cheikh I. Seye ◽  
...  

Sjögren's syndrome (SS) is an autoimmune disorder characterized by inflammation and dysfunction of salivary glands, resulting in impaired secretory function. The production of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) is elevated in exocrine glands of patients with SS, although little is known about the effects of these cytokines on salivary epithelial cell functions necessary for saliva secretion, including tight junction (TJ) integrity and the establishment of transepithelial ion gradients. The present study demonstrates that chronic exposure of polarized rat parotid gland (Par-C10) epithelial cell monolayers to TNF-α and IFN-γ decreases transepithelial resistance (TER) and anion secretion, as measured by changes in short-circuit current ( Isc) induced by carbachol, a muscarinic cholinergic receptor agonist, or UTP, a P2Y2 nucleotide receptor agonist. In contrast, TNF-α and IFN-γ had no effect on agonist-induced increases in the intracellular calcium concentration [Ca2+]i in Par-C10 cells. Furthermore, treatment of Par-C10 cell monolayers with TNF-α and IFN-γ increased paracellular permeability to normally impermeant proteins, altered cell and TJ morphology, and downregulated the expression of the TJ protein, claudin-1, but not other TJ proteins expressed in Par-C10 cells. The decreases in TER, agonist-induced transepithelial anion secretion, and claudin-1 expression caused by TNF-α, but not IFN-γ, were reversible by incubation of Par-C10 cell monolayers with cytokine-free medium for 24 h, indicating that IFN-γ causes irreversible inhibition of cellular activities associated with fluid secretion in salivary glands. Our results suggest that cytokine production is an important contributor to secretory dysfunction in SS by disrupting TJ integrity of salivary epithelium.


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