• Molecules and Cells
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• 제25권3호
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• pp.323-331
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• 2008

Plants are continually exposed to a variety of potentially pathogenic microbes, and the interactions between plants and pathogenic invaders determine the outcome, disease or disease resistance. To defend themselves, plants have developed a sophisticated immune system. Unlike animals, however, they do not have specialized immune cells and, thus all plant cells appear to have the innate ability to recognize pathogens and turn on an appropriate defense response. Using genetic, genomic and biochemical methods, tremendous advances have been made in understanding how plants recognize pathogens and mount effective defenses. The primary immune response is induced by microbe-associated molecular patterns (MAMPs). MAMP receptors recognize the presence of probable pathogens and evoke defense. In the co-evolution of plant-microbe interactions, pathogens gained the ability to make and deliver effector proteins to suppress MAMP-induced defense responses. In response to effector proteins, plants acquired R-proteins to directly or indirectly monitor the presence of effector proteins and activate an effective defense response. In this review we will describe and discuss the plant immune responses induced by two types of elicitors, PAMPs and effector proteins.

• 한국어병학회지
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• 제20권2호
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• pp.189-200
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• 2007

잉어의 선천성 면역 인자가 관여하는 항바이러스 면역 반응을 조사하기 위해 UV-inactivated SVCV, Poly I:C 및 Con A를 주사한 후 3일째 라이소자임 활성, 혈청 내 보체의 살균능력 및 식세포의 활성산소량을 조사하였다. 그 결과, 모든 시험구에서 혈청 내 라이소자임의 활성은 유의적인 차이를 나타나지 않았으나, 두신 조직의 라이소자임 활성은 대조구에 비해 유의적으로 증가하였다. 또한, 혈청 내 보체의 살균 능력도 모든 시험구에서 대조구와 유의적인 차이가 없었다. 그러나 식세포의 활성은 UV-inactivated SVCV 시험구에서는 농도에 따라 증가한 것으로 나타났으며, Poly I:C 및 Con A 시험구에서는 저농도에서 활성이 증가한 것으로 나타났다. 바이러스에 대한 방어력을 조사하기 위해 주사 후 4일째 1×104 TCID50/fish 농도의 SVCV로 인위 감염한 결과 UV-inactivated SVCV 및 Poly I:C 시험구에서는 Con A 시험구에 비해 높은 방어력을 나타내었다. 또한, Poly I:C 시험구에서 라이소자임 및 식세포 활성이 다소 감소한 고농도에서도 높은 방어력이 유도된 것으로 나타나 이러한 결과는 Poly I:C에 의해 자극된 또 다른 비특이적 면역 인자가 SVCV에 대한 방어반응에 관여한 것으로 추정된다.

• 대한한의학회지
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• 제17권2호
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• pp.227-236
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• 1996

The effect of Ligustrum Lucidum(LL) on the production of nitric oxide (NO) and superoxide by murine peritoneal macrophages were investigated. Stimulation of the cells with LL in the presence or absence of interferon-r(IFN-r) resulted in the increased accumulation of nitrite in the medium. To further examine the mechanism of LL induced. NO Synthesis, we evaluated the secretion of tumor necrosis $factor-{\alpha}(TNF-{\alpha})$ by LL in murine macrophages. Treatment of LL increased the secretion of bioactive $TNF-{\alpha}$ in cultured medium. In addition, LL induced NO production was decreased by the treatment of anti-murine $TNF-{\alpha}$. neutralizing antibodies, indicating that LL induced superoxide production was decreased by the treatment of anti-murine $TNF-{\alpha}$ neutralizing antibodies. These data suggested that LL induced superoxide production was related to $TNF-{\alpha}$ secretion. In conclusion, our results indicates that LL may enhance innate immune response and be applied as a immunoregulating drug improving phagocytosis.

• Clinical and Experimental Pediatrics
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• 제58권7호
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• pp.239-244
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• 2015

The complement system is part of the innate immune response and as such defends against invading pathogens, removes immune complexes and damaged self-cells, aids organ regeneration, confers neuroprotection, and engages with the adaptive immune response via T and B cells. Complement activation can either benefit or harm the host organism; thus, the complement system must maintain a balance between activation on foreign or modified self surfaces and inhibition on intact host cells. Complement regulators are essential for maintaining this balance and are classified as soluble regulators, such as factor H, and membrane-bound regulators. Defective complement regulators can damage the host cell and result in the accumulation of immunological debris. Moreover, defective regulators are associated with several autoimmune diseases such as atypical hemolytic uremic syndrome, dense deposit disease, age-related macular degeneration, and systemic lupus erythematosus. Therefore, understanding the molecular mechanisms by which the complement system is regulated is important for the development of novel therapies for complement-associated diseases.

• Asian-Australasian Journal of Animal Sciences
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• 제31권9호
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• pp.1516-1524
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• 2018

Objective: Defensins are a large family of antimicrobial peptides and components of the innate immune system that invoke an immediate immune response against harmful pathogens. Defensins are classified into alpha-, beta-, and theta-defensins. Avian species only possess beta-defensins (AvBDs), and approximately 14 AvBDs (AvBD1-AvBD14) have been identified in chickens to date. Although substantial information is available on the conservation and phylogenetics, limited information is available on the expression and regulation of AvBD8 in chicken immune tissues and cells. Methods: We examined AvBD8 protein expression in immune tissues of White Leghorn chickens (WL) by immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (RT-qPCR). In addition, we examined AvBD8 expression in chicken T-, B-, macrophage-, and fibroblast-cell lines and its regulation in these cells after lipopolysaccharide (LPS) treatment by immunocytochemistry and RT-qPCR. Results: Our results showed that chicken AvBD8 protein was strongly expressed in the WL intestine and in macrophages. AvBD8 gene expression was highly upregulated in macrophages treated with different LPS concentrations compared with that in T- and B-cell lines in a time-independent manner. Moreover, chicken AvBD8 strongly interacted with other AvBDs and with other antimicrobial peptides as determined by bioinformatics. Conclusion: Our study provides the expression and regulation of chicken AvBD8 protein in immune tissues and cells, which play crucial role in the innate immunity.

• IMMUNE NETWORK
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• 제11권1호
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• pp.11-41
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• 2011

The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA.

• Biomolecules & Therapeutics
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• 제21권4호
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• pp.251-257
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• 2013

Inflammatory skin diseases such as atopic dermatitis (AD) and rosacea were complicated by barrier abrogation and deficiency in innate immunity. The first defender of epidermal innate immune response is the antimicrobial peptides (AMPs) that exhibit a broad-spectrum antimicrobial activity against multiple pathogens, including Gram-positive and Gram-negative bacteria, viruses, and fungi. The deficiency of these AMPs in the skin of AD fails to protect our body against virulent pathogen infections. In contrast to AD where there is a suppression of AMPs, rosacea is characterized by overexpression of cathelicidin antimicrobial peptide (CAMP), the products of which result in chronic epidermal inflammation. In this regard, AMP generation that is controlled by a key ceramide metabolite S1P-dependent mechanism could be considered as alternate therapeutic approaches to treat these skin disorders, i.e., Increased S1P levels strongly stimulated the CAMP expression which elevated the antimicrobial activity against multiple pathogens resulting the improved AD patient skin.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2018년도 춘계 종합학술대회 논문집
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• pp.551-552
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• 2018

K/BxN serum can induce arthritis in normal mice because of abundant autoantibodies that trigger an innate inflammatory response in joints. To determine whether IL-17 is involved in the pathogenesis of serum-induced arthritis, we injected wild-type and $IL-17^{-/-}$ mice with K/BxN serum and evaluated them for signs of arthritis. Unlike wild-type mice, $IL-17^{-/-}$ mice did not show any signs of arthritis. IL-17 was produced predominantly by $CD3^-CD4^-gdTCR^-NK1.1^-Sca1^{int}Thy1^{hi}$ cells residing in the inflamed synovial tissue. When synovial cells extracted from normal joints were stimulated with IL-23 or autoantibody-containing immune complexes, a substantial fraction of $Sca1^{int}Thy1^{hi}$ cells produced IL-17. Thus, we have identified a novel population of IL-17-producing innate synovial cells that play a crucial role in the development of K/BxN serum-induced arthritis.

• Molecules and Cells
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• 제23권1호
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• pp.1-10
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• 2007

Invading pathogens are recognized by diverse germline-encoded pattern-recognition receptors (PRRs) which are distributed in three different cellular compartments: extracellular, membrane, and cytoplasmic. In mammals, the major extracellular PRRs such as complements may first encounter the invading pathogens and opsonize them for clearance by phagocytosis which is mediated by membrane-associated phagocytic receptors including complement receptors. The major membrane-associated PRRs, Toll-like receptors, recognize diverse pathogens and generate inflammatory signals to coordinate innate immune responses and shape adaptive immune responses. Furthemore, certain membrane-associated PRRs such as Dectin-1 can mediate phagocytosis and also induce inflammatory response. When these more forefront detection systems are avoided by the pathogens, cytoplasmic PRRs may play major roles. Cytoplasmic caspase-recruiting domain (CARD) helicases such as retinoic acid-inducible protein I (RIG-I)/melanoma differentiation-associated gene 5 (MDA5), mediate antiviral immunity by inducing the production of type I interferons. Certain members of nucleotide-binding oligomerization domain (NOD)-like receptors such as NALP3 present in the cytosol form inflammasomes to induce inflammatory responses upon ligand recognition. Thus, diverse families of PRRs coordinately mediate immune responses against diverse types of pathogens.

• Molecules and Cells
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• 제42권1호
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• pp.1-7
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• 2019

Macrophage is an important innate immune cell that not only initiates inflammatory responses, but also functions in tissue repair and anti-inflammatory responses. Regulating macrophage activity is thus critical to maintain immune homeostasis. Tyro3, Axl, and Mer are integral membrane proteins that constitute TAM family of receptor tyrosine kinases (RTKs). Growing evidence indicates that TAM family receptors play an important role in anti-inflammatory responses through modulating the function of macrophages. First, macrophages can recognize apoptotic bodies through interaction between TAM family receptors expressed on macrophages and their ligands attached to apoptotic bodies. Without TAM signaling, macrophages cannot clear up apoptotic cells, leading to broad inflammation due to over-activation of immune cells. Second, TAM signaling can prevent chronic activation of macrophages by attenuating inflammatory pathways through particular pattern recognition receptors and cytokine receptors. Third, TAM signaling can induce autophagy which is an important mechanism to inhibit NLRP3 inflammasome activation in macrophages. Fourth, TAM signaling can inhibit polarization of M1 macrophages. In this review, we will focus on mechanisms involved in how TAM family of RTKs can modulate function of macrophage associated with anti-inflammatory responses described above. We will also discuss several human diseases related to TAM signaling and potential therapeutic strategies of targeting TAM signaling.