• IMMUNE NETWORK
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• v.14 no.6
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• pp.328-332
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• 2014

Dexamethasone (Dex) was shown to inhibit the differentiation, maturation, and antigen-presenting function of dendritic cells (DC) when added during DC generation or maturation stages. Here, we examined the direct effects of Dex on MHC-restricted antigen processing. Macrophages were incubated with microencapsulated ovalbumin (OVA) in the presence of different concentrations of Dex for 2 h, and the efficacy of OVA peptide presentation was evaluated using OVA-specific CD8 and CD4 T cells. Dex inhibited both class I- and class II-restricted presentation of OVA to T cells; this inhibitory effect on antigen presentation was much more potent in immature macrophages than in mature macrophages. The presentation of the exogenously added OVA peptide SIINFEKL was not blocked by Dex. In addition, short-term treatment of macrophages with Dex had no discernible effects on the phagocytic activity, total expression levels of MHC molecules or co-stimulatory molecules. These results demonstrate that Dex inhibits intracellular processing events of phagocytosed antigens in macrophages.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.224-229
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• 2002

Triazine herbicide has been reported to directly suppress the immune response. In the present study, we examined various functions of murine peritoneal macrophages that were isolated and stimulated with LPS after simazine (300 and 600 mg/kg body weight), a triazine herbicide, was administered every day for 4 weeks. Simazine decreased the capacity of phagocytosis, compared to those of carboxymethylcellulose (CMC)-treated control group. In addition, the production of NO and TNF-$\alpha$ was decrcased in macrophages of simazinetreated mice. However, the production of hydrogen peroxide ($H_{2}O_{2}$) was not altered. In vitro tumoricidal activity of in vivo simazine-treated macrophages was reduced against target cell. B 16 melanoma. Taken together, these results suggested that simazine might have the immunosuppressive effect on macrophages after in vivo exposure, which was related to the reduction of tumoricidal activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1252-1257
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• 1997

In order to investigate the immunomodulatory mechanism of white ginseng, the effects of total saponin of Ginsenoside Rb$_2$component on the phagocytosis and reactive oxygen intermediate(ROI) production of mouse peritoneal macrophages were studied. Both phagocytosis assay nitrobluetetrazolium reduction test showed 20$\mu\textrm{g}$/ml concentration of total saponin significantly increased the activity of phagocytosis and production of ROI. Also cytokine gene expression of the macrophages was analyzed using reverse transcription polymerase chain reaction. In the RT-PCR assay, 20$\mu\textrm{g}$/ml concentration of either total saponin or Ginsenoside Rb$_2$increased IL-1 and TNF expression of the macrophages.

• BMB Reports
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• v.52 no.6
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• pp.360-372
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• 2019

Macrophages play an essential role not only in mediating the first line of defense but also in maintaining tissue homeostasis. In response to extrinsic factors derived from a given tissue, macrophages activate different functional programs to produce polarized macrophage populations responsible for inducing inflammation against microbes, removing cellular debris, and tissue repair. However, accumulating evidence has revealed that macrophage polarization is pivotal in the pathophysiology of metabolic syndromes and cancer, as well as in infectious and autoimmune diseases. Recent advances in transcriptomic and metabolomic studies have highlighted the link between metabolic rewiring of macrophages and their functional plasticity. These findings imply that metabolic adaption to their surrounding microenvironment instructs activation of macrophages with functionally distinct phenotypes, which in turn probably leads to the pathogenesis of a wide spectrum of diseases. In this review, we have introduced emerging concepts in immunometabolism with focus on the impact on functional activation of macrophages. Furthermore, we have discussed the implication of macrophage plasticity on the pathogenesis of metabolic syndromes and cancer, and how the disease microenvironment manipulates macrophage metabolism with regard to the pathophysiology.

• BMB Reports
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• v.55 no.11
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• pp.519-527
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• 2022

Macrophage activation has long been implicated in a myriad of human pathophysiology, particularly in the context of the dysregulated capacities of an unleashing intracellular or/and extracellular inflammatory response. A growing number of studies have functionally coupled the macrophages' inflammatory capacities with dynamic metabolic reprogramming which occurs during activation, albeit the results have been mostly interpreted through classic metabolism point of view; macrophages take advantage of the rewired metabolism as a source of energy and for biosynthetic precursors. However, a specific subset of metabolic products, namely immune-modulatory metabolites, has recently emerged as significant regulatory signals which control inflammatory responses in macrophages and the relevant extracellular milieu. In this review, we introduce recently highlighted immuno-modulatory metabolites, with the aim of understanding their physiological and pathological relevance in the macrophage inflammatory response.

• Natural Product Sciences
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• v.14 no.3
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• pp.206-213
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• 2008

This study was designed to investigate the anti-inflammatory effects of mangiferin isolated from the rhizome of Anemarrhena asphodeloides, a natural polyphenol, on lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Mangiferin dose-dependently inhibited LPS-induced nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ productions in RAW 264.7 macrophages and peritoneal macrophages isolated from C57BL/6 mice. Consistent with these data, mangiferin suppressed the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. In addition, the release of tumor necrosis $factor-{\alpha}$($TNF-{\alpha}$) and interleukin-6 (IL-6), and the mRNA expression levels of these cytokines were reduced by mangiferin in a dose-dependent manner. Moreover, mangiferin effectively inhibited the transcriptional activation of nuclear factor-kappa B $(NF-{\kappa}B)$. These results suggest that the anti-inflammatory properties of mangiferin are caused by iNOS, COX-2, $TNF-{\alpha}$, and IL-6 down-regulation due to $(NF-{\kappa}B)$ inhibition in RAW 264.7 macrophages.

• The Journal of Internal Korean Medicine
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• v.28 no.2
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• pp.377-384
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• 2007

Objective : Immune potentiation including activation of T cells, B cells, macrophages, and dendritic cells is known to play a key role in prevention and treatment of patients with cancer. In this study, we investigated the effects of Acanthopanax sessiliflorus (AR) on the immune system, especially on thymocytes, splenocytes, and macrophages. Methods : We investigated the effects of AR on proliferation of splenocytes in normal mice, and the effects on proliferation of splenocytes and thymocytes in tumor-bearing mice. In addition, the effect of AR on NO production using macrophages was investigated. Results : Treatment with AR accelerated proliferation of splenocytes in vitro. AR also accelerated thymocyte proliferation, but did not affect splenocytes proliferation in normal mice. In contrast, AR accelerated proliferation of splenocytes and thymocytes significantly in tumor bearing mice. In addition, NO production level from macrophages was elevated by treatment with AR. Conclusion : These results demonstrate that AR has anti-cancer activities and related mechanisms are involved in immune potentiation such as acceleration of immune cell proliferation and elevation of NO production level in macrophages. In addition, we also demonstrate the possibilities of AR as complementary and alternative medicine to standard anti-cancer drugs.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.329-334
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• 2004

Ischemia/reperfusion(I/R) injury of the rat testis causes germ cell death and infiltration of inflammatory cells. To investigate the mechanism of germ cell death in torsion of the rat testis, apoptosis and macrophage activation were studied using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling(TUNEL) method and immunohistochemistry in the testes of Sprague-Dawley rats subjected to 1.5 h of ischemia, followed by 0, 1, 3, 6, 12, 24, 48 and 96 h of reperfusion. Apoptotic, TUNEL-positive cells were found at the base of the seminiferous epithelia after I/R. TUNEL-positive cells were significantly increased 6 h after repair of the torsion, and there was a significant peak in apoptosis 24 h after reperfusion, as compared with normal or sham-operated controls. In contrast, histological evidence of germ cell necrosis in the seminiferous tubules was first visible 24 h after reperfusion. In the testis of sham-operated rats, ED2-positive resident macrophages were found diffusely in the interstitial space, while ED1-positive monocyte-like macrophages were rarely found. After I/R, ED1-positive cells were significantly increased beginning 12 h after reperfusion, while ED2-positive immunoreactivity did not change during the experimental period. Together, the results of this study confirmed that increased numbers of ED1-positive macrophages, but not resident ED2-positive macrophages, infiltrated the interstitial space surrounding damaged tubules and induced germcell death.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.4
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• pp.991-995
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• 2003

The purpose of this research was to investigate the effects of unripened fruits and ripened fruits of Rubus coreanus Miquel on murine peritoneal macrophages. The 70% ethyl alcohol extracts (20 or 100 mg/kg) of unripened fruits (RCE-I) and of ripened fruits (RCE-II) were administered p.o. once a day for 7 days to mice. RCE-I and RCE-II decreased the phagocytic activity of murine peritoneal macrophages and the production of nitric oxide. Also, RCE-I and RCE-II increased the production of tumor necrosis factor- a from peritoneal macrophages. In general, the immuno-suppressive action of RCE-I on macrophages was more potent than those of RCE-II. These results suggest that the fruits of Rubus coreanus Miquel regulates the non-specific immune response via decrease of phagocytic activity and increase of production of tumor necrosis factor- a from murine peritoneal macrophages.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1217-1222
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• 2006

The purpose of this research was to investigate the effects of the administration of Juglandis Semen without inner cortex (JE) or with inner cortex (JEIC) on activity of splenocytes and peritoneal macrophages in BALB/C mice. JE (300 mg/kg, p.o.) did not affect the cell viability of T- and B-lymphocytes in murine splenocytes, but JEIC (300mg/kg, p.o.) increased the cell viability of T- and B-lymphocytes. Furthermore, JE decreased the population of B220$^+$ cells in splenocytes, but JEIC enhanced the population of Thyl$^+$ cells. Also, JEIC enhanced the population of splenic CD4$^+$ cells. JE decreased the production of nitric oxide and the phagocytic activity of peritoneal macrophages, but JEIC increased the production of nitric oxide and the phagocytic activity of peritoneal macrophages. These results suggest that JEIC is more potent than JE against the immune response induced by splenocytes and macrophages.