• Molecules and Cells
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• 제39권11호
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• pp.777-782
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• 2016

The innate immune system has evolved to detect and destroy invading pathogens before they can establish systemic infection. To successfully eradicate pathogens, including viruses, host innate immunity is activated through diverse pattern recognition receptors (PRRs) which detect conserved viral signatures and trigger the production of type I interferon (IFN) and pro-inflammatory cytokines to mediate viral clearance. Viral persistence requires that viruses co-opt cellular pathways and activities for their benefit. In particular, due to the potent antiviral activities of IFN and cytokines, viruses have developed various strategies to meticulously modulate intracellular innate immune sensing mechanisms to facilitate efficient viral replication and persistence. In this review, we highlight recent advances in the study of viral immune evasion strategies with a specific focus on how Kaposi's sarcoma-associated herpesvirus (KSHV) effectively targets host PRR signaling pathways.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.444-450
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• 2005

Epidermal growth factor (EGF) activates many intracellular effector molecules, which subsequently influence the expression levels of many genes involved in cell growth, apoptosis and signal transduction, etc. In this study, the early response of gene expressions due to EGF treatment was monitored using oligonucleotide DNA microarrays in rat schwannoma cell lines. An immunoblotting experiment showed the successful activation of EGF receptors and an effector protein, STAT5, due to EGF treatment. The microarray study showed that 35 genes were significantly induced and 2 were repressed within 60 min after the treatment. The list of induced genes included early growth response 1, suppressor of cytokine signaling 3, c-fos, interferon regulatory factor 1 and early growth response 2, etc. According to the microarray data, six of these were induced by more than 10-fold, and showed at least two different induction patterns, indicating complicated regulatory mechanisms in the EGF signal transduction.

• IMMUNE NETWORK
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• 제14권5호
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• pp.249-254
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• 2014

Allergic asthma is a chronic pulmonary inflammatory disease characterized by reversible airway obstruction, hyperresponsiveness and eosinophils infiltration. Toll-like receptors (TLRs) signaling are closely associated with asthma and have emerged as a novel therapeutic target in allergic disease. The functions of TLR3 and TLR4 in allergic airway inflammation have been studied; however, the precise role of TIR-domain-containing adapter-inducing interferon-${\beta}$ (TRIF), the adaptor molecule for both TLR3 and TLR4, is not yet fully understood. To investigate this, we developed a mouse model of OVA-induced allergic airway inflammation and compared the severity of allergic airway inflammation in WT and $TRIF^-/^-$ mice. Histopathological assessment revealed that the severity of inflammation in airway inflammation in TRIF-deficient mice was comparable to that in WT mice. The total number of cells recovered from bronchoalveolar lavage fluid did not differ between WT and TRIF-deficient mice. Moreover, TRIF deficiency did not affect Th1 and Th2 cytokine production in lung tissue nor the level of serum OVA-specific IgE, $IgG_1$ and $IgG_{2c}$. These findings suggest that TRIF-mediated signaling may not be critical for the development of allergic airway inflammation.

• Tuberculosis and Respiratory Diseases
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• 제58권1호
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• pp.11-17
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• 2005

연구배경 : 결핵의 발병에 유전적인 소인이 존재하며 숙주 면역 반응에 $IFN-{\gamma}$가 중요한 역할을 한다고 알려져 있다. 파종성 NTM 또는 BCG 감염증 환자에서 $IFN-{\gamma}$ 수용체 유전자 돌연변이가 밝혀져 있는데, 결핵 환자에서 $IFN-{\gamma}$ 수용체의 부분결핍 유무는 잘 알려져 있지 않았다. 방 법 : 2개 이상의 장기를 침범한 파종성 결핵 환자 6명을 대상으로 염기순서분석을 통해 $IFN-{\gamma}$ 수용체 1과 $IFN-{\gamma}$ 수용체 2의 부분결핍을 초래하는 유전자 이상이 있는지를 살펴보았다. 결 과 : $IFN-{\gamma}R1$의 부분결핍을 초래하는 I87T와 818delT 818del4, 818insA 그리고 $IFN-{\gamma}R2$의 부분결핍을 초래하는 R114C 돌연변이 등 기존에 보고된 유전자 이상은 발견되지 않았다. 결 론 : 본 연구의 대상인 6명의 파종성 결핵 환자에서 $IFN-{\gamma}$ 수용체의 부분결핍을 초래하는 유전자 이상은 발견되지 않았다.

• 생명과학회지
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• 제33권12호
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• pp.1062-1073
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• 2023

우울증은 개인과 사회에 부정적인 영향을 미치는 흔한 정신질환이지만 그 원인은 아직 명확히 밝혀져 있지 않다. 스트레스는 우울증의 주요 위험인자이며, 염증을 유발하여 우울증에 대한 취약성을 증가시키는 것으로 알려져 있다. 수많은 연구는 우울증과 염증의 강한 연관성을 제안하고 있다. 우울증 환자 혈액에서는 IL-1β, IL-6, IL-12, TNF-α 및 IFN-γ와 같은 친염증성 사이토카인이 증가하였으며, IL-4, IL-10 및 TGF-β와 같은 항염증성 사이토카인이 감소하였다. 설치류에 친염증성 사이토카인을 투여하면 우울 유사 행동이 관찰되는 반면, 항염증제를 투여하면 우울 증상이 완화된다. 이러한 연구들은 우울증의 병인에 염증의 중요성을 강조하고 있다. 우울증에서 염증이 활성화되는 기전에 관한 다양한 연구들이 진행되고 있다. 최근 연구에서는 스트레스로 유발되는 무균 염증의 중요성을 밝히고 있다. 병원균의 감염이 없는 상태에서 신체 및 심리적 스트레스로 인해 염증 과정이 활성화되는 것을 무균 염증이라 한다. 스트레스는 무균 염증을 활성화하기 위해 DAMPs (damage-associated molecular patterns)로 알려진 내인성 인자의 방출을 촉진시키며, 방출된 DAMPs는 해당 수용체인 PRRs (pattern recognition receptors)에 결합함으로서 신호전달을 통해 친염증성 사이토카인 생성을 증가시킨다. 본 종설에서 무균 염증의 조절 장애에 대한 전임상 및 임상 증거를 바탕으로 우울증에서 DAMP의 역할을 검토하고자 한다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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• pp.5513-5518
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• 2013

IFN-${\gamma}$ plays an indirect anti-cancer role through the immune system but may have direct negative effects on cancer cells. It regulates the viability of gastric cancer cells, so we examined whether it affects their proliferation and how that might be brought about. We exposed AGS, HGC-27 and GES-1 gastric cancer cell lines to IFN-${\gamma}$ and found significantly reduced colony formation ability. Flow cytometry revealed no effect of IFN-${\gamma}$ on apoptosis of cell lines and no effect on cell aging as assessed by ${\beta}$-gal staining. Microarray assay revealed that IFN-${\gamma}$ changed the mRNA expression of genes related to the cell cycle and cell proliferation and migration, as well as chemokines and chemokine receptors, and immunity-related genes. Finally, flow cytometry revealed that IFN-${\gamma}$ arrested the cells in the G1/S phase. IFN-${\gamma}$ may slow proliferation of some gastric cancer cells by affecting the cell cycle to play a negative role in the development of gastric cancer.

• Toxicological Research
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• 제31권1호
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• pp.11-16
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• 2015

Our body's immune system has defense mechanisms against pathogens such as viruses and bacteria. Immune responses are primarily initiated by the activation of toll-like receptors (TLRs). In particular, TLR4 is well-characterized and is known to be activated by gram-negative bacteria and tissue damage signals. TLR4 requires myeloid differentiation factor 2 (MD2) as a co-receptor to recognize its ligand, lipopolysaccharides (LPS), which is an extracellular membrane component of gram-negative bacteria. Gambogic acid is a xanthonoid isolated from brownish or orange resin extracted from Garcinia hanburyi. Its primary effect is tumor suppression. Since inflammatory responses are related to the development of cancer, we hypothesized that gambogic acid may regulate TLR4 activation. Our results demonstrated that gambogic acid decreased the expression of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6, IL-12, and $IL-1{\beta}$) in both mRNA and protein levels in bone marrow-derived primary macrophages after stimulation with LPS. Gambogic acid did not inhibit the activation of Interferon regulatory factor 3 (IRF3) induced by TBK1 overexpression in a luciferase reporter gene assay using IFN-${\beta}$-PRD III-I-luc. An in vitro kinase assay using recombinant TBK1 revealed that gambogic acid did not directly inhibit TBK1 kinase activity, and instead suppressed the binding of LPS to MD2, as determined by an in vitro binding assay and confocal microscopy analysis. Together, our results demonstrate that gambogic acid disrupts LPS interaction with the TLR4/MD2 complex, the novel mechanism by which it suppresses TLR4 activation.

• Journal of Veterinary Science
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• 제24권1호
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• pp.13.1-13.11
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• 2023

Background: Highly pathogenic avian influenza viruses (HPAIVs) is an extremely contagious and high mortality rates in chickens resulting in substantial economic impact on the poultry sector. Therefore, it is necessary to elucidate the pathogenic mechanism of HPAIV for infection control. Objective: Gene set enrichment analysis (GSEA) can effectively avoid the limitations of subjective screening for differential gene expression. Therefore, we performed GSEA to compare HPAI-infected resistant and susceptible Ri chicken lines. Methods: The Ri chickens Mx(A)/BF2(B21) were chosen as resistant, and the chickens Mx(G)/BF2(B13) were selected as susceptible by genotyping the Mx and BF2 genes. The tracheal tissues of HPAIV H5N1 infected chickens were collected for RNA sequencing followed by GSEA analysis to define gene subsets to elucidate the sequencing results. Results: We identified four differentially expressed pathways, which were immune-related pathways with a total of 78 genes. The expression levels of cytokines (IL-1β, IL-6, IL-12), chemokines (CCL4 and CCL5), type interferons and their receptors (IFN-β, IFNAR1, IFNAR2, and IFNGR1), Jak-STAT signaling pathway genes (STAT1, STAT2, and JAK1), MHC class I and II and their co-stimulatory molecules (CD80, CD86, CD40, DMB2, BLB2, and B2M), and interferon stimulated genes (EIF2AK2 and EIF2AK1) in resistant chickens were higher than those in susceptible chickens. Conclusions: Resistant Ri chickens exhibit a stronger antiviral response to HPAIV H5N1 compared with susceptible chickens. Our findings provide insights into the immune responses of genetically disparate chickens against HPAIV.

• Journal of Veterinary Science
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• 제24권3호
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• pp.37.1-37.14
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• 2023

Background: Toll-like receptor (TLR) agonists have been used as adjuvants to modulate immune responses in both animals and humans. Objectives: The objective of this study was to evaluate the combined effects of the TLR 4 agonist monophosphoryl lipid A (MPL) and the TLR 3 agonist polyinosinic:polycytidylic acid (Poly I:C) on equine peripheral blood mononuclear cells (PBMCs), monocyte-derived dendritic cells (MoDCs), and bone marrow-derived mesenchymal stromal cells (BM-MSCs). Methods: The PBMCs, MoDCs, and BM-MSCs collected from three mixed breed horses were treated with MPL, Poly I:C, and their combination. The mRNA expression of interferon gamma (IFN-γ), interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-12p40, tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) was determined using real-time polymerase chain reaction. Results: The combination of MPL and Poly I:C significantly upregulated immunomodulatory responses in equine cells/ without cytotoxicity. The combination induced greater mRNA expression of pro-inflammatory cytokines IFN-γ and IL-6 than MPL or Poly I:C stimulation alone in PBMCs. In addition, the combination induced significantly higher mRNA expression of IL-1β, IL-6, and IL-12p40 in MoDCs, and IL-8, MCP-1, and VEGF in BM-MSCs compared to stimulation with a single TLR agonist. Conclusions: The combination of MPL and Poly I:C can be used as a potential adjuvant candidate for vaccines to aid in preventing infectious diseases in horses.

• The Korean Journal of Physiology and Pharmacology
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• 제18권4호
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• pp.313-320
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• 2014

The study was conducted to investigate the role of vitamin E in the high altitude hypoxia-induced damage to the intestinal barrier in rats. Sprague-Dawley rats were divided into control (Control), high altitude hypoxia (HH), and high altitude hypoxia + vitamin E (250 mg/kg $BW^*d$) (HV) groups. After the third day, the HH and HV groups were placed in a hypobaric chamber at a stimulated elevation of 7000 m for 5 days. The rats in the HV group were given vitamin E by gavage daily for 8 days. The other rats were given equal volume saline. The results showed that high altitude hypoxia caused the enlargement of heart, liver, lung and kidney, and intestinal villi damage. Supplementation with vitamin E significantly alleviated hypoxia-caused damage to the main organs including intestine, increased the serum superoxide dismutase (SOD) (p< 0.05), diamino oxidase (DAO) (p< 0.01) levels, and decreased the serum levels of interleukin-2 (IL-2) (p< 0.01), interleukin-4 (IL-4) (p<0.001), interferon-gamma ($IFN-{\gamma}$) (p<0.01) and malondialdehyde (MDA) (p<0.001), and decreased the serum erythropoietin (EPO) activity (p<0.05). Administration of vitamin E significantly increased the S-IgA (p<0.001) in ileum and significantly improved the expression levels of occludin and $I{\kappa}B{\alpha}$, and decreased the expression levels of hypoxia-inducible factor 1 alpha and 2 alpha ($HIF-1{\alpha}$ and $HIF-2{\alpha}$), Toll-like receptors (TLR4), P-$I{\kappa}B{\alpha}$ and nuclear factor-${\kappa}B$ p65(NF-${\kappa}B$ P65) in ileum compared to the HH group. This study suggested that vitamin E protectis from intestinal injury caused by high altitude hypoxia environment. These effects may be related to the HIF and TLR4/NF-${\kappa}B$ signaling pathway.