• Title/Summary/Keyword: Functions of lectins

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Animal lectins: potential receptors for ginseng polysaccharides

  • Loh, So Hee;Park, Jin-Yeon;Cho, Eun Hee;Nah, Seung-Yeol;Kang, Young-Sun
    • Journal of Ginseng Research
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    • v.41 no.1
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    • pp.1-9
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    • 2017
  • Panax ginseng Meyer, belonging to the genus Panax of the family Araliaceae, is known for its human immune system-related effects, such as immune-boosting effects. Ginseng polysaccharides (GPs) are the responsible ingredient of ginseng in immunomodulation, and are classified as acidic and neutral GPs. Although GPs participate in various immune reactions including the stimulation of immune cells and production of cytokines, the precise function of GPs together with its potential receptor(s) and their signal transduction pathways have remained largely unknown. Animal lectins are carbohydrate-binding proteins that are highly specific for sugar moieties. Among many different biological functions in vivo, animal lectins especially play important roles in the immune system by recognizing carbohydrates that are found exclusively on pathogens or that are inaccessible on host cells. This review summarizes the immunological activities of GPs and the diverse roles of animal lectins in the immune system, suggesting the possibility of animal lectins as the potential receptor candidates of GPs and giving insights into the development of GPs as therapeutic biomaterials for many immunological diseases.

Studies on Lectins from Marine Shells (III) : Screening of Lectin-like Agglutinins from Marine Shells

  • Chung, See-Ryun;Kim, Jang-Hwan;Suh, Young-Ah;Jeunechung, Kyung-Hee
    • Archives of Pharmacal Research
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    • v.9 no.4
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    • pp.201-203
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    • 1986
  • Forty species of marine shells were collected from Korean coasts and studied extensively for their lectin activities by using erythrocytes of human blooc A, AB, B. O group and rabbit blood. In total, 7 species contained lectines :Neptunea intersculpta, Omphalius nigerrimus and Scapharca subcrenata, blood group nonspecific; Saxidomus purpuratus, human blood A and AB group specific; Lepidozona coreana, Tegilarca granosa and Neptunea polycosta, rabbit blood specific.

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Purification and characterization of a lectin from hard roe of skipjack tuna, Katsuwonus pelamis

  • Jung, Won-Kyo;Park, Pyo-Jam;Kim, Se-Kwon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.146-147
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    • 2001
  • Lectins or carbohydrate-binding proteins are proteins of non-immune origin, which is able to agglutinate cells, and precipitate polysaccharides and glycoconjugates (Goldstein et al., 1980). Lectins with diverse physiological roles are widely distributed to the various plant, microorganisms, invertebrates and vertebrates. The ubiquitous occurrence of lectins in nature and their ability to recognize complementary sugars provided a stimulus for the continuous research for their biochemical properties and physiological functions (Raz and Lotan, 1987). (omitted)

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Recent Advances in the Innate Immunity of Invertebrate Animals

  • Iwanaga, Sadaaki;Lee, Bok-Luel
    • BMB Reports
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    • v.38 no.2
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    • pp.128-150
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    • 2005
  • Invertebrate animals, which lack adaptive immune systems, have developed other systems of biological host defense, so called innate immunity, that respond to common antigens on the cell surfaces of potential pathogens. During the past two decades, the molecular structures and functions of various defense components that participated in innate immune systems have been established in Arthropoda, such as, insects, the horseshoe crab, freshwater crayfish, and the protochordata ascidian. These defense molecules include phenoloxidases, clotting factors, complement factors, lectins, protease inhibitors, antimicrobial peptides, Toll receptors, and other humoral factors found mainly in hemolymph plasma and hemocytes. These components, which together compose the innate immune system, defend invertebrate from invading bacterial, fungal, and viral pathogens. This review describes the present status of our knowledge concerning such defensive molecules in invertebrates.

Synthesis and Secretion of Mutant Mannose-Binding Lectin (돌연변이 Mannose-binding Lectin 합성과 세포 병리적 연구)

  • Jang, Ho-Jung;Chung, Kyung Tae
    • Journal of Life Science
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    • v.23 no.3
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    • pp.347-354
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    • 2013
  • Innate immunity is the ability to differentiate infectious agents from self. The innate immune system is comprised of a complicated network of recognition and effector molecules that act together to protect the host in the early stage of an infectious challenge. Mannose-binding lectin (MBL or mannose-binding protein, MBP) belongs to the family of $Ca^{2+}$-dependent lectins (C-type lectin with a collagen-like domain), which are considered an important component of innate immunity. While it is associated with increased risk and severity of infections and autoimmunity, the most frequent immuno-deficiency syndrome was reported to be low MBL level in blood. Deficiency of human MBL is caused by mutations in the coding region of the MBL gene. Rat homologue gene of human MBL gene was used to study functions of wild type and mutant MBL proteins. Although extensive studies have yielded the structural information of MBL, the functions of MBL, especially mutant MBL, still require investigation. We previously reported the cloning of rat wild-type MBL gene and the production of a truncated form of MBL protein and its antibody. Here, we present the cloning of mutant MBL cDNA in collagen-like domain (R40C, G42D, and G45E) using site-directed mutagenesis and differential behaviors of wild type and mutant MBL in cells. The major difference between wild type and mutant MBL was that while wild type MBL was secreted, mutant MBL was inhibited for secretion, retained in endoplasmic reticulum, and still functioned as a lectin.

Increased expression of galectin-9 in experimental autoimmune encephalomyelitis (실험적 자가면역성 뇌척수염을 유도한 마우스에서 Galectin-9의 과발현)

  • Cho, Jinhee;Bing, So Jin;Kim, Areum;Yu, Hak Sun;Lim, Yoon-Kyu;Shin, Taekyun;Choi, Jonghee;Jee, Youngheun
    • Korean Journal of Veterinary Research
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    • v.54 no.4
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    • pp.209-218
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    • 2014
  • Experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS), reflects pathophysiologic steps in MS such as the influence of T cells and antibodies reactive to the myelin sheath, and the cytotoxic effect of cytokines. Galectin-9 (Gal-9) is a member of animal lectins that plays an essential role in various biological functions. The expression of Gal-9 is significantly enhanced in MS lesions; however, its role in autoimmune disease has not been fully elucidated. To identify the role of Gal-9 in EAE, we measured changes in mRNA and protein expression of Gal-9 as EAE progressed. Expression increased with disease progression, with a sharp rise occurring at its peak. Gal-9 immunoreactivity was mainly expressed in astrocytes and microglia of the central nervous system (CNS) and macrophages of spleen. Flow cytometric analysis revealed that $Gal-9^+CD11b^+$ cells were dramatically increased in the spleen at the peak of disease. Increased expression of tumor necrosis factor (TNF)-R1 and p-Jun N-terminal kinase (JNK) was observed in the CNS of EAE mice, suggesting that TNF-R1 and p-JNK might be key regulators contributing to the expression of Gal-9 during EAE. These results suggest that identification of the relationship between Gal-9 and EAE progression is critical for better understanding Gal-9 biology in autoimmune disease.