scholarly journals Exosomes released from macrophages infected with intracellular pathogens stimulate a proinflammatory response in vitro and in vivo

Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3234-3244 ◽  
Author(s):  
Sanchita Bhatnagar ◽  
Kazuhiko Shinagawa ◽  
Francis J. Castellino ◽  
Jeffrey S. Schorey

Abstract Intracellular pathogens and the molecules they express have limited contact with the immune system. Here, we show that macrophages infected with intracellular pathogens Mycobacterium tuberculosis, M bovis BCG, Salmonella typhimurium, or Toxoplasma gondii release from cells small vesicles known as exosomes which contain pathogen-associated molecular patterns (PAMPs). These exosomes, when exposed to uninfected macrophages, stimulate a proinflammatory response in a Toll-like receptor– and myeloid differentiation factor 88–dependent manner. Further, exosomes isolated from the bronchoalveolar lavage fluid (BALF) of M bovis BCG–infected mice contain the mycobacteria components lipoarabinomannan and the 19-kDa lipoprotein and can stimulate TNF-α production in naive macrophages. Moreover, exosomes isolated from M bovis BCG– and M tuberculosis–infected macrophages, when injected intranasally into mice, stimulate TNF-α and IL-12 production as well as neutrophil and macrophage recruitment in the lung. These studies identify a previously unknown function for exosomes in promoting intercellular communication during an immune response to intracellular pathogens, and we hypothesize that extracellular release of exosomes containing PAMPs is an important mechanism of immune surveillance.

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Natalia K. Kordulewska ◽  
Justyna Topa ◽  
Małgorzata Tańska ◽  
Anna Cieślińska ◽  
Ewa Fiedorowicz ◽  
...  

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ting-Yeu Dai ◽  
Chih-Hua Wang ◽  
Kun-Nan Chen ◽  
I-Nung Huang ◽  
Wei-Sheng Hong ◽  
...  

We assayed the effects of velvet antler (VA) of Formosan sambar deer (Cervus unicolor swinhoei) and its extracts on the anti-infective activity against pathogenicStaphylococcus aureus in vitroandin vivoin this study.In vitrodata indicated that the VA extracts stimulated the proliferation of resting splenocytes and macrophages in a dose-dependent manner up to the highest concentration used (150 μg mL−1). The production of proinflammatory cytokines (TNF-α, IL-6, IL-12) by lipoteichoic acid was significantly suppressed after being cocultured with the VA extracts in a dose-dependent manner. Animal test inS. aureus-infected mice demonstrated that the numbers of bacteria determined in the kidneys and peritoneal lavage fluid ofS. aureus-infected mice were significantly higher than those found in the same organs of mice pretreated with the VA samples. Moreover, the highly enhanced phagocytic activity of macrophages was further verified afterin vitrotreatment with the VA samples. The protective mechanisms of the VA samples might include an immune enhancer and an inflammatory cytokine suppressor.


2017 ◽  
Vol 43 (5) ◽  
pp. 2074-2087 ◽  
Author(s):  
Liling Yang ◽  
Xiangjun Zhou ◽  
Weijuan Huang ◽  
Qin Fang ◽  
Jianlan Hu ◽  
...  

Background/Aims: Forsythia suspensa Vahl. (Oleaceae) fruits are widely used in traditional Chinese medicine to treat pneumonia, typhoid, dysentery, ulcers and oedema. Antibacterial and anti-inflammatory activities have been reported for phillyrin (PHN), the main ingredient in Forsythia suspensa Vahl fruits, in vitro. However, the underlying mechanisms in vivo remain poorly defined. In this study, we discovered that PHN exerted potent anti-inflammatory effects in lethal LPS-induced neutrophil inflammation by suppressing the MyD88-dependent signalling pathway in zebrafish. Methods: LPS-yolk microinjection was used to induce a lethal LPS-infected zebrafish model. The effect of PHN on the survival of zebrafish challenged with lethal LPS was evaluated using survival analysis. The effect of PHN on neutrophil inflammation grading in vivo was assessed by tracking neutrophils with a transgenic line. The effects of PHN on neutrophil production and migration were analysed by SB+ cell counts during consecutive hours after modelling. Additionally, key cytokines and members of the MyD88 signalling pathway that are involved in inflammatory response were detected using quantitative RT-PCR. To assess gene expression changes during consecutive hours after modelling, the IL-1β, IL-6, TNF-α, MyD88, TRIF, ERK1/2, JNK, IκBa and NF-κB expression levels were measured. Results: PHN could protect zebrafish against a lethal LPS challenge in a dose-dependent manner, as indicated by decreased neutrophil infltration, reduced tissue necrosis and increased survival rates. Up-regulated IL-1β, IL-6 and TNF-α expression also showed the same tendencies of depression by PHN. Critically, PHN significantly inhibited the LPS-induced activation of MyD88, IκBa, and NF-κB but did not affect the expression of ERK1/2 MAPKs or JNK MAPKs in LPS-stimulated zebrafish. Additionally, PHN regulated the MyD88/IκBα/NF-κB signalling pathway by controlling IκBα, IL-1β, IL-6, and TNF-α expression. Conclusion: This study provides a rationale for the clinical application of PHN as an anti-inflammatory agent.


2020 ◽  
Author(s):  
Chuan-jiang Liu ◽  
Qiang Fu ◽  
Wenjing Zhou ◽  
Xu Zhang ◽  
Rui Chen ◽  
...  

Abstract Background: Methylprednisolone (MP) is a synthetic corticosteroid with potent anti-inflammatory and antioxidant properties used as therapy for a variety of diseases. The underlying mechanism of MP to reduce acute pancreatitis still needs to be elucidated.Methods: Twenty-four male C57BL/6 mice (6-8 weeks) were used to establish SAP mouse model by administering an intraperitoneal injection of Cae and LPS. Amylase expression levels of serum and PLF were measured with an amylase assay kit. The concentrations of IL-1β and TNF-α in the serum and PLF were detected by ELISA. The level of pancreatic and lung tissue damage and inflammation was assessed by H&E staining and immunofluorescence staining. Western blot and qPCR were used to detect the expression levels of NLRP3, IL-1β and TNF-αin vivo and in vitro.Results: In this study, we found MP, used in the early phase of SAP, decreased the levels of IL-1β and TNF-α in serum and peritoneal lavage fluids (PLF), reduced the level of serum amylase and the expression of MPO in lung tissue, attenuated the pathological injury of the pancreas and lungs in a dose-dependent manner. The expression of NLRP3 and IL-1β in pancreas and lungs was down-regulated significantly depending on the MP concentration. In vitro, MP reduced the levels of IL-1β and TNF-α by down-regulating the expression of NLRP3, IL-1β and p-NF-κB in isolated peritoneal macrophages. Conclusion: MP can attenuate the injury of pancreas and lungs, and the inflammatory response in SAP mice by down-regulating the activation of NF-κB and the NLRP3 inflammasome.


2018 ◽  
Vol 115 (15) ◽  
pp. 3930-3935 ◽  
Author(s):  
Dongshi Chen ◽  
Jingshan Tong ◽  
Liheng Yang ◽  
Liang Wei ◽  
Donna B. Stolz ◽  
...  

Necroptosis, a form of regulated necrotic cell death, is governed by RIP1/RIP3-mediated activation of MLKL. However, the signaling process leading to necroptotic death remains to be elucidated. In this study, we found that PUMA, a proapoptotic BH3-only Bcl-2 family member, is transcriptionally activated in an RIP3/MLKL-dependent manner following induction of necroptosis. The induction of PUMA, which is mediated by autocrine TNF-α and enhanced NF-κB activity, contributes to necroptotic death in RIP3-expressing cells with caspases inhibited. On induction, PUMA promotes the cytosolic release of mitochondrial DNA and activation of the DNA sensors DAI/Zbp1 and STING, leading to enhanced RIP3 and MLKL phosphorylation in a positive feedback loop. Furthermore, deletion of PUMA partially rescues necroptosis-mediated developmental defects in FADD-deficient embryos. Collectively, our results reveal a signal amplification mechanism mediated by PUMA and cytosolic DNA sensors that is involved in TNF-driven necroptotic death in vitro and in vivo.


2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 478 ◽  
Author(s):  
Rasha Al-Rikabi ◽  
Hanady Al-Shmgani ◽  
Yaser Hassan Dewir ◽  
Salah El-Hendawy

(1) Background: Plant flavonoids are efficient in preventing and treating various diseases. This study aimed to evaluate the ability of hesperidin, a flavonoid found in citrus fruits, in inhibiting lipopolysaccharide (LPS) induced inflammation, which induced lethal toxicity in vivo, and to evaluate its importance as an antitumor agent in breast cancer. The in vivo experiments revealed the protective effects of hesperidin against the negative LPS effects on the liver and spleen of male mice. (2) Methods: In the liver, the antioxidant activity was measured by estimating the concentration of glutathione (GSH) and catalase (CAT), whereas in spleen, the concentration of cytokines including IL-33 and TNF-α was measured. The in vitro experiments including MTT assay, clonogenity test, and sulforhodamine 101 stain with DAPI (4′, 6-diamidino-2-phenylindole) were used to assess the morphological apoptosis in breast cancer cells. (3) Results: The results of this study revealed a significant increase in the IL-33 and TNF-α cytokine levels in LPS challenged mice along with a considerable elevation in glutathione (GSH); moreover, the catalase (CAT) level was higher compared to that of the control group. Cytotoxicity of the MCF-7 cell line revealed significant differences among the groups treated with different concentrations when compared to the control groups, in a concentration-dependent manner. Hesperidin significantly inhibited the colony formation of MCF7 cells when compared to that of control. Clear changes were observed in the cell shape, including cell shrinkage and chromatin condensation, which were associated with a later apoptotic stage. (4) Conclusion: The results indicate that hesperidin might be a potential candidate in preventing diseases.


Author(s):  
Toa Ookawara ◽  
Ryota Aihara ◽  
Ai Morimoto ◽  
Naoki Iwashita ◽  
Keigo Kurata ◽  
...  

Abstract Previously, researchers have demonstrated that mycotoxin deoxynivalenol (DON) significantly enhances immunocyte activation. However, the interaction between DON exposure and immune disorders remains unclear. In this study, we aimed to investigate whether acute and subacute oral exposure to DON exacerbates the development of respiratory allergy using a mite allergen (Dermatophagoides farina, Derf)-induced mouse model of asthma. The direct relationship between DON exposure and asthma development was examined following acute oral DON administration (0, 0.1, or 0.3 mg/kg body weight), immediately before the final mite allergen challenge. Simultaneously, the influence of subacute oral exposure via low dose DON contaminated wheat (0.33 ppm) was evaluated using the same settings. To detect the proinflammatory effects of DON exposure, we examined the total and Derf-specific serum IgE levels, histology, number of immunocytes, and cytokine and chemokine secretion. Acute oral DON significantly enhanced the inflammatory responses, including cellular infiltration into bronchoalveolar lavage fluid, infiltration of immunocytes and cytokine production in local lymph nodes, and cytokine levels in lung tissues. Corresponding proinflammatory responses were observed in a mouse group exposed to subacute oral DON. In vivo results were validated by in vitro experiments using the human bronchial epithelial (BEAS-2B) and human eosinophilic leukemia (EOL-1) cell lines. Following exposure to DON, the secretion of interleukin (IL)-1β, IL-6, IL-8, and/or tumor necrosis factor-α in BEAS-2B cells, as well as EoL-1 cells, increased significantly. Our findings indicate that DON exposure is significantly involved in the proinflammatory response observed in respiratory allergy.


1998 ◽  
Vol 42 (11) ◽  
pp. 2824-2829 ◽  
Author(s):  
Seiichi Kobayashi ◽  
Tsutomu Kawata ◽  
Akifumi Kimura ◽  
Kaname Miyamoto ◽  
Koichi Katayama ◽  
...  

ABSTRACT As a consequence of blood-borne bacterial sepsis, endotoxin or lipopolysaccharide (LPS) from the cell walls of gram-negative bacteria can trigger an acute inflammatory response, leading to a series of pathological events and often resulting in death. To block this inflammatory response to endotoxin, a novel lipid A analogue, E5531, was designed and synthesized as an LPS antagonist, and its biological properties were examined in vitro and in vivo. In murine peritoneal macrophages, E5531 inhibited the release of tumor necrosis factor alpha (TNF-α) by Escherichia coli LPS with a 50% inhibitory concentration (IC50) of 2.2 nM, while E5531 elicited no significant increases in TNF-α on its own. In support of a mechanism consistent with antagonism of binding to a cell surface receptor for LPS, E5531 inhibited equilibrium binding of radioiodinated LPS ([125I]2-(r-azidosalicylamido)-1, 3′-dithiopropionate-LPS) to mouse macrophages with an IC50 of 0.50 μM. E5531 inhibited LPS-induced increases in TNF-α in vivo when it was coinjected with LPS into C57BL/6 mice primed with Mycobacterium bovis bacillus Calmette-Guérin (BCG). In this model, the efficacy of E5531 was inversely correlated to the LPS challenge dose, consistent with a competitive antagonist-like mechanism of action. Blockade of the inflammatory response by E5531 could further be demonstrated in other in vivo models: E5531 protected BCG-primed mice from LPS-induced lethality in a dose-dependent manner and suppressed LPS-induced hepatic injury in Propionibacterium acnes-primed or galactosamine-sensitized mice. These results argue that the novel synthetic lipid A analogue E5531 can antagonize the action of LPS in in vitro and suppress the pathological effects of LPS in vivo in mice.


2005 ◽  
Vol 289 (2) ◽  
pp. L186-L195 ◽  
Author(s):  
Celine A. Beamer ◽  
Andrij Holian

Alveolar macrophages express the class A scavenger receptor (CD204) (Babaev VR, Gleaves LA, Carter KJ, Suzuki H, Kodama T, Fazio S, and Linton MF. Arterioscler Thromb Vasc Biol 20: 2593–2599, 2000); yet its role in vivo in lung defense against environmental particles has not been clearly defined. In the current study, CD204 null mice (129Sv background) were used to investigate the link between CD204 and downstream events of inflammation and fibrosis following silica exposure in vivo. CD204−/− macrophages were shown to recognize and uptake silica in vitro, although this response was attenuated compared with 129Sv wild-type mice. The production of tumor necrosis factor-α in lavage fluid was significantly enhanced in CD204 null mice compared with wild-type mice following silica exposure. Moreover, after exposure to environmental particles, CD204−/− macrophages exhibited improved cell viability in a dose-dependent manner compared with wild-type macrophages. Finally, histopathology from a murine model of chronic silicosis in 129Sv wild-type mice displayed typical focal lesions, interstitial thickening with increased connective tissue matrix, and cellular infiltrate into air space. In contrast, CD204−/− mice exhibited little to no deposition of collagen, yet they demonstrated enhanced accumulation of inflammatory cells largely composed of neutrophils. Our findings point to an important role of CD204 in mounting an efficient and appropriately regulated immune response against inhaled particles. Furthermore, these results indicate that the functions of CD204 are critical to the development of fibrosis and the resolution of inflammation.


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