• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.189-196
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• 1997

The purpose of this study is to determine whether nitric oxide is involved in the extracellular killing of Trichomoncs uasinalis by mouse (BALB/c) peritoneal macrophages and RAW264.7 cells activated with LPS or rIFN-γ and also to observe the effects of various chemicals which affect the production of reactive nitrogen intermediates (RNl) in the cytotoxicity against T. vnginnlis. The cytotoxicity was measured by counting the release of (3H)-thymidine from labelled protozoa and NOa was assayed by Griess reaction. Nemonomethyl-L-arginine (L-NMHA), Nenitro-L-arginine methyl ester (NAME) and arginase inhibited cytotoxicity to T. vaginnlis and nitrite production by activated mouse perioneal macrophagrs and RAW 264.7 cells. The addition of excess L-arginine competitively restored trichomonacidal activity of macrophages. Exogenous addition of FeSO4 inhibited cytotoxicity to T. vaginaLis and nitric products of macrophages. From above results, it is assumed that nitric oxide plays an important role in the host defense mechanism of macrophages against T ucfinalis.

• Journal of Life Science
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• v.27 no.8
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• pp.873-878
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• 2017

We previously reported that NAD(P)H:quinone oxidoreductase 1 (NQO1)-knockout (KO) mice exhibited spontaneous inflammation in the gut. We also found that NQO1-KO mice showed highly increased inflammatory responses compared with NQO1-WT control mice when subjected to DSS-induced experimental colitis. In a Clostridium difficile toxin-induced mouse enteritis model, NQO1-KO mice were also sensitive compared with NQO1-WT mice. Moreover, numerous studies have shown that NQO1 is functionally associated with immune regulation. Here, we assessed whether NQO1 defects can alter macrophage activation. We found that peritoneal macrophages isolated from NQO1-KO mice produced more IL-6 and $TNF-{\alpha}$ than those isolated from NQO1-WT mice. Moreover, the dicumarol-induced inhibition of NQO1 significantly increased IL-6 and $TNF-{\alpha}$ production in peritoneal macrophages isolated from NQO1-WT mice, as well as in the cultured mouse macrophage cell line, RAW264.7. These results indicate that NQO1 may negatively regulate the activation of macrophages. Knockout or chemical inhibition of NQO1 markedly reduced the expression of $I{\kappa}B$ (inhibitor of $NF{\kappa}B$) in both mouse peritoneal macrophages and RAW264.7 cells. Finally, RAW264.7 cells treated with dicumarol exhibited morphological changes reflecting macrophage activation. Our results suggest that NQO1 may suppress the $NF{\kappa}B$ pathways in macrophages, thereby suppressing the activation of these cells. Thus, immunosuppressive activity may be among the many possible functions of NQO1.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.91-91
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• 2022

작약은 염증성 질환을 치료하기 위해 사용되어 온 전통 약용식물이다. 최근 작약은 대식세포에서 면역조절인자의 분비를 증가시키고 포식작용을 증가시킨다고 보고되었다. 그리하여 본 연구에서 추출조건별 작약의 대식세포 활성화 유도를 비교하였다. 온도조건 별 작약추출물은 4℃에서 60℃까지는 면역조절인자의 분비를 증가시켰지만, 80℃에서는 면역조절인자의 분비가 다소 감소하였다. 60℃에서 시간별 추출조건에서는 1시간에 24시간까지 면역조절인자의 분비가 유사하였다. 따라서 본 연구결과를 종합해 볼 때, 작약은 60℃에서 1시간 추출하는 것이 대식세포 활성화를 위한 최적 조건이라고 판단된다.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.158-164
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• 2021

Hypertriglyceridemia is the main risk factor for atherosclerosis. It is reported that triglyceride (TG) induces macrophage cell death, and is involved in the formation of plaques and development of atherosclerosis. We previously reported that TG-induced cell death of macrophages is mediated via pannexin-1 activation, which increases the extracellular ATP and subsequent increase in potassium efflux, thereby activating the caspase-2/caspase-1/apoptotic caspases, including the caspase-8 pathway. Contrarily, some studies have reported that caspase-8 is an upstream molecule of caspase-1 and caspase-2 in several cellular processes. Therefore, this study was undertaken to investigate whether caspase-8 influences its upstream molecules in TG-stimulated macrophage cell death. We first confirmed that caspase-8 induces caspase-3 activation and poly ADP-ribose polymerase (PARP) cleavage in TG-treated macrophages. Next, we determined that the inhibition of caspase-8 results in reduced caspase-1 and -2 activity, which are upstream molecules of caspase-8 in TG-induced cell death of macrophages. We also found that ATP treatment restores the caspase-8 inhibitor-induced caspase-2 activity, thereby implying that caspase-8 affects the upstream molecules responsible for increasing the extracellular ATP levels in TG-induced macrophage cell death. Taken together, these findings indicate that caspase-8 potentiates the TG-induced macrophage cell death by activating its upstream molecules.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.510-517
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• 2002

Effects of wheat arabinoxylan on mouse spleen lymphocytes and peritoneal macrophages were examined in vitro. Among three wheat arabinoxylans (A1: low MW, A2: medium MW, A3: high MW), A3$(50{\sim}100\;{\mu}g/mL)$ increased the viability of spleen lymphocytes up to $114{\sim}125%$ of the control. A1 and A3 $(20\;{\mu}g/mL)$ increased the viability of lipopolysaccharide-treated lymphocytes synergistically. Viability of murine peritoneal macrophages treated with wheat arabinoxylans $(10{\sim}100{\mu}g/mL)$ was increased up to $135{\sim}175%$ of the control. The cytotoxic activity of macrophages against murine lymphocytic leukemic cell increased in the presence of wheat arabinoxylan. Phagocytic index of macrophages treated with wheat arabinozylans $(20\;{\mu}g/mL)$ significantly increased $197{\sim}232%$ compared with the control, and lysosomal phosphatase and myeloperoxidase activities also increased significantly (p<0.05). Treatment of wheat arabinoxylans tended to decrease nitrite production, but significantly stimulated $H_2O_2\;and\;O_2$ productions of macrophages (p<0.05). These results indicate that the immunostimulating effect of wheat arabinoxylan may be closely related with lysosomal enzyme activity and reactive oxygen intermediate production of macrophages.

• Parasites, Hosts and Diseases
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• v.28 no.2
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• pp.85-90
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• 1990

This study was aimed to observe the direct and Iymphokine-activated cell mediated cytotoxic effects against Trichomenas waginalis by mouse peritoneal macrophages. Cytotoxicity was measured as release of 3H-thymidine from prelabeled protozoa, and tested in U-bottom microtiter plates. A 0.1 ml suspension of labeled protozoa (2{\times}10^5/ml$) was placed in each well, followed by 0.1 ml of a suspension containing increasing numbers of peritoneal cells. After a 24 hr incubation at $37^{\circ}C$, 0.1ml of the supernatant was collected and counted in liquid scintillation counter. Mouse peritoneal macrophages had appreciable level of spontaneous cytotoxicity against T. maginalis at the effector to target cell ratios from 5 : 1 to 50 : 1, Treatment of macrophages with Iymphokine, produced by PHA-stimulated spleen cells, increased the cytotoxicity in comparison with resident macrophages against T. vaginalis. The degree of macrophage activation for the killing was not dependent upon the Iymphokine concentration. Peritoneal cells adherent to plastic displayed significant levels of cytotoxicity against T. vaginalis. This study indicates that mouse peritoneal macrophages are spontaneously cytotoxic for T. waginalis and Iymphokine increases the cytotoxicity by activating macrophages to kill T. vaginalis.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.986-990
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• 2004

The immunomodulatory effect of Codonopsis lanceolata based on the production of cytokines and the activation of macrophage was studied. The mRNA expression of nitric oxide synthase (iNOS) was gradually induced after 24 hr treatment of Codonopsis lanceolata, and NO production was a maximum after 24 hr treatment with 1 mg/mL. RAW 264.7 cell on in vitro treatment with Codonopsis lanceolata induced mRNA of cytokines such as interleukin-1(IL-1)${\beta}$, interleukin-6(IL-6), tumor necrosis $factor(TNF)-{\alpha}\;and\;interferon(IFN)-{\gamma}$; $IL-1{\beta}$ and IL-6 mRNA were gradually induced up to 24 hr, $TNF-{\alpha}\;mRNA$ was regularly induced up to 24 hr, and $IFN-{\gamma}\;mRNA$ level was a maximum within 1 hr. These results suggest that Codonopsis lanceolata exerts as an effective immunomodulator and enhances antitumor activity of macrophages.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.377-383
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• 2021

In this study, we investigated in vitro immunostimulatory activity of fruit extracts from Pyrus ussuriensis var. hakunensis (Nakai) T.B. Lee (PUF) using mouse macrophage RAW264.7 cells. PUF increased the production of immunostimulatory factors such as NO, iNOS, IL-1β, IL-6 and TNF-α, and phagocytic activity in RAW264.7 cells. The inhibition of TLR2 and TLR4 blocked PUF-mediated production of immunostimulatory factors in RAW264.7 cells. In addition, the inhibition of MAPKs signaling pathway reduced PUF-mediated production of immunostimulatory factors. From these results, PUF may have immunostimulatory activity via TLR2/4-mediated activation of MAPKs signaling pathway. Therefore, PUF expected to be used as a potential immune-enhancing agent.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.129-138
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• 1991

Tetrahymena pyriformis is a free-living ciliate protozoan in the freshwater system. Experiments were carried out to determine whether intraperitoneal administration of T. pyriformis (GL strain) to mice activates macrophages to be able to kill Toxoplasma gondii tachyzoites in vitro. Mice were also injected intraperitoneally with several synthetic activators; dimethyldioctadecylammonium bromide (DDA), dextran sulfate, complete Freund's adjutant (CFA) as well as Toxoplasma and Tetrehymena Iysates in order to activate mouse peritoneal macrophages. One week after the administration of activators, peritoneal cells were harvested and the adherent macrophages were challenged with Toxoplasma tachyzoites. Macrophage monolayers were then fixed with absolute methanol after washing, and stained with Giemsa solution. The percentage of the adherent cells infected and total number of organisms per 100 macrophages were calculated to make toxoplasma-cidal activity of macrophages according to the cultivation time. Peritoneal macrophages from mice administered with Tetrahymena exhibited significant protection against target parasites as compared with those treated with synthetic activators. Among non-biological synthetic activators, DDA was evaluated as an ellcellent activator.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.245-252
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• 2020

Macrophage cell death contributes to the formation of plaque, leading to the development of atherosclerosis. The accumulation of triglyceride (TG) is also associated with the pathogenesis of atherosclerosis. A previous study reported that TG induces the cell death of macrophages. This study examined whether the cytoplasmic release of cathepsin B from lysosome is associated with the TG-induced cell death of macrophage. The release of cathepsin B was increased in the TG-treated THP-1 macrophages, but the TG treatment did not affect cathepsin B expression. Furthermore, the inhibition of cathepsin B by its inhibitor, CA-074 Me, partially inhibited the TG-induced cell death of macrophage. TG-triggered macrophage cell death is mediated by the activation of caspase-1, -2, and apoptotic caspases. Therefore, this study investigated whether cathepsin B is implicated in the activation of these caspases. The inhibition of cathepsin B blocked the activation of caspase-7, -8, and -1 but did not affect the activity of caspase-3, -9, and -2. Overall, these results suggest that TG-induced cytoplasmic cathepsin B causes THP-1 macrophage cell death by activating caspase-1, leading to subsequent activation of the extrinsic apoptotic pathway.