• 한국균학회소식:학술대회논문집
• /
• 2015.11a
• /
• pp.23-23
• /
• 2015

Rice blast disease caused by M. oryzae is the most devastating fungal disease in rice. During the infection process, M. oryzae secretes a large number of glycosyl hydrolase (GH) proteins into the apoplast to digest host cell wall and assist fungal ingress into host tissues. In this study, we identified a novel M. oryze arabinofuranosidase B (MoAbfB) which is secreted during fungal infection. Live-cell imaging exhibited that fluorescent labeled MoAbfB was highly accumulated in fungal invasive structures such as appressorium, tips of penetration peg, biotrophic interfacial complex (BIC), as well as invasive hyphal tip. Deletion of MoAbfB mutants extended biotrophic phase followed by enhanced disease severity, whereas, over-expression of OsMoAbfB mutant induced rapid defense responses and enhanced rice resistance to M. oryzae infection. Furthermore, exogenous treatment of MoAbfB protein showed inhibition of fungal infection via priming of defense gene expression. We later found that the extract of MoAbfB degraded rice cell wall fragments could also induce host defense activation, suggesting that not MoAbfB itself but oligosaccharides (OGs) derived from MoAbfB dissolved rice cell wall elicited rice innate immunity.

• BMB Reports
• /
• v.41 no.4
• /
• pp.267-277
• /
• 2008

Insects mount a robust innate immune response against a wide array of microbial pathogens. The hallmark of the Drosophila humoral immune response is the rapid production of anti-microbial peptides in the fat body and their release into the circulation. Two recognition and signaling cascades regulate expression of these antimicrobial peptide genes. The Toll pathway is activated by fungal and many Gram-positive bacterial infections, whereas the immune deficiency (IMD) pathway responds to Gram-negative bacteria. Recent work has shown that the intensity and duration of the Drosophila immune response is tightly regulated. As in mammals, hyperactivated immune responses are detrimental, and the proper down-modulation of immunity is critical for protective immunity and health. In order to keep the immune response properly modulated, the Toll and IMD pathways are controlled at multiple levels by a series of negative regulators. In this review, we focus on recent advances identifying and characterizing the negative regulators of these pathways.

• The Microorganisms and Industry
• /
• v.20 no.3
• /
• pp.14-21
• /
• 1994

Low molecular weight molecules and high molecular weight substances were found to have anti-tumor and immuno-modulating activity. Previously polysaccharides have been received much attention because of adhesives, food additives or animal foods (Whistler et al., 1976). In effort of developing new anti-tumor substances with low toxicity, numerous polysaccharides from yeast, algae, bacteria, higher plants and especially fungi have been investigated for anti-tumor and immuno-modulating activities. Thus the high molecular weight molecule was reported to have anti-tumor activity through host mediated immunity. In this brief article, attention will be paid to polysaccharides which is especially fungal origin.

• Mycobiology
• /
• v.48 no.5
• /
• pp.373-382
• /
• 2020

Laccases (EC 1.10.3.2), a group of multi-copper oxidases (MCOs), play multiple biological functions and widely exist in many species. Fungal laccases have been extensively studied for their industrial applications, however, there was no database specially focused on fungal laccases. To provide a comparative genomics platform for fungal laccases, we have developed a comparative genomics platform for laccases and MCOs (http://laccase.riceblast.snu.ac. kr/). Based on protein domain profiles of characterized sequences, 3,571 laccases were predicted from 690 genomes including 253 fungi. The number of putative laccases and their properties exhibited dynamic distribution across the taxonomy. A total of 505 laccases from 68 genomes were selected and subjected to phylogenetic analysis. As a result, four clades comprised of nine subclades were phylogenetically grouped by their putative functions and analyzed at the sequence level. Our work would provide a workbench for putative laccases mainly focused on the fungal kingdom as well as a new perspective in the identification and classification of putative laccases and MCOs.

• BMB Reports
• /
• v.38 no.2
• /
• pp.128-150
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.11
• /
• pp.1626-1639
• /
• 2020

In Caenorhabditis elegans, SHN-1 is the homologue of SHANK, a scaffolding protein. In this study, we determined the molecular basis for SHN-1/SHANK in the regulation of innate immune response to fungal infection. Mutation of shn-1 increased the susceptibility to Candida albicans infection and suppressed the innate immune response. After C. albicans infection for 6, 12, or 24 h, both transcriptional expression of shn-1 and SHN-1::GFP expression were increased, implying that the activated SHN-1 may mediate a protection mechanism for C. elegans against the adverse effects from fungal infection. SHN-1 acted in both the neurons and the intestine to regulate the innate immune response to fungal infection. In the neurons, GLR-1, an AMPA ionotropic glutamate receptor, was identified as the downstream target in the regulation of innate immune response to fungal infection. GLR-1 further positively affected the function of SER-7-mediated serotonin signaling and antagonized the function of DAT-1-mediated dopamine signaling in the regulation of innate immune response to fungal infection. Our study suggests the novel function of SHN-1/SHANK in the regulation of innate immune response to fungal infection. Moreover, our results also denote the crucial role of neurotransmitter signals in mediating the function of SHN-1/SHANK in regulating innate immune response to fungal infection.

• IMMUNE NETWORK
• /
• v.22 no.6
• /
• pp.46.1-46.25
• /
• 2022

T-helper-17 (Th17) cells and related IL-17-producing (type17) lymphocytes are abundant at the epithelial barrier. In response to bacterial and fungal infection, the signature cytokines IL-17A/F and IL-22 mediate the antimicrobial immune response and contribute to wound healing of injured tissues. Despite their protective function, type17 lymphocytes are also responsible for various chronic inflammatory disorders, including inflammatory bowel disease (IBD) and colitis associated cancer (CAC). A deeper understanding of type17 regulatory mechanisms could ultimately lead to the discovery of therapeutic strategies for the treatment of chronic inflammatory disorders and the prevention of cancer. In this review, we discuss the current understanding of the development and function of type17 immune cells at the intestinal barrier, focusing on the impact of microbiota-immune interactions on intestinal barrier homeostasis and disease etiology.

• YAKHAK HOEJI
• /
• v.56 no.6
• /
• pp.366-371
• /
• 2012

In this present study, we determined whether or not there is an immunoadjuvant effect of ochnaflavone, a biflavone isolated from Lonicera japonica. As an antigenic source, the cell wall (CACW) of Candida albicans, a fungal pathogen, was used. CACW consists of 95% carbohydrate (mannan). In the experiments, BALB/c mice were immunized with emersion forms of CACW combined with or without ochnaflavone (Och) in the presence of IFA containing mineral oil or CACW alone. Then, the amounts of antisera collected from these mice groups were measured by the ELISA method. Data from these experiments showed that CACW combined with Och (CACW/Och/IFA) provoked the production of antisera app. 2.2 or 5 times more than the corresponding CACW/IFA or CACW alone (CACW/DPBS), respectively, in mice (P<0.05). We further examined the immune response type induced by Och. Analysis of the values of the IgG1/IgG2a ratios obtained from IgG isotyping revealed that Och induced Th2-immunity more dominantly than Th1. This finding was confirmed by cytokine profile. CACW/Och/IFA formulation induced IL-4 (Th2-type cytokine) more than IFN${\gamma}$ (Th1-type cytokine) as compared with CACW/IFA and CACW/DPBS formulations (P<0.05). All data combined, Och appears to have an immunoadjuvant activity that may convert Th1 immunity into Th2 immunity.

• Molecules and Cells
• /
• v.25 no.4
• /
• pp.553-558
• /
• 2008

Essential aspects of the innate immune response to microbial infection appear to be conserved between insects and mammals. In order to identify new Drosophila melanogaster genes involved in the immune response, we performed gene expression profiling of Drosophila SL2 cells stimulated with bacterial (LPS/PGN) or fungal (curdlan) components using a cDNA microarray that contained 5,405 Drosophila cDNAs. We found that some genes were similarly regulated by LPS/PGN and curdlan. However, a large number, belonging to the functional classes of cell organization, development, signal transduction, morphogenesis, cell cycle, and DNA replication, displayed significant differences in their transcription profiles between the two treatments, demonstrating that bacterial and fungal components induce different immune response even in an in vitro cell system.

• The Plant Pathology Journal
• /
• v.37 no.6
• /
• pp.505-511
• /
• 2021

Interaction of a pathogen with its host plant requires both flexibility and rapid shift in gene expression programs in response to environmental cues associated with host cells. Recently, a growing volume of data on the diversity and ubiquity of internal RNA modifications has led to the realization that such modifications are highly dynamic and yet evolutionarily conserved system. This hints at these RNA modifications being an additional regulatory layer for genetic information, culminating in epitranscriptome concept. In plant pathogenic fungi, however, the presence and the biological roles of RNA modifications are largely unknown. Here we delineate types of RNA modifications, and provide examples demonstrating roles of such modifications in biology of filamentous fungi including fungal pathogens. We also discuss the possibility that RNA modification systems in fungal pathogens could be a prospective target for new agrochemicals.