• 제목/요약/키워드: host factors

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Beyond Viral Interferon Regulatory Factors: Immune Evasion Strategies

  • Myoung, Jinjong;Lee, Shin-Ae;Lee, Hye-Ra
    • Journal of Microbiology and Biotechnology
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    • 제29권12호
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    • pp.1873-1881
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    • 2019
  • The innate immune response serves as a first-line-of-defense mechanism for a host against viral infection. Viruses must therefore subvert this anti-viral response in order to establish an efficient life cycle. In line with this fact, Kaposi's sarcoma-associated herpesvirus (KSHV) encodes numerous genes that function as immunomodulatory proteins to antagonize the host immune system. One such mechanism through which KSHV evades the host immunity is by encoding a viral homolog of cellular interferon (IFN) regulatory factors (IRFs), known as vIRFs. Herein, we summarize recent advances in the study of the immunomodulatory strategies of KSHV vIRFs and their effects on KSHV-associated pathogenesis.

Exploring Staphylococcus aureus Virulence Factors; Special Emphasis on Staphyloxanthin

  • Yehia, Fatma Al-zahraa A.;Yousef, Nehal;Askoura, Momen
    • 한국미생물·생명공학회지
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    • 제49권4호
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    • pp.467-477
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    • 2021
  • Staphylococcus aureus is a well-known pathogen that can cause diseases in humans. It can cause both mild superficial skin infections and serious deep tissue infections, including pneumonia, osteomyelitis, and infective endocarditis. To establish host infection, S. aureus manages a complex regulatory network to control virulence factor production in both temporal and host locations. Among these virulence factors, staphyloxanthin, a carotenoid pigment, has been shown to play a leading role in S. aureus pathogenesis. In addition, staphyloxanthin provides integrity to the bacterial cell membrane and limits host oxidative defense mechanisms. The overwhelming rise of Staphylococcus resistance to routinely used antibiotics has necessitated the development of novel anti-virulence agents to overcome this resistance. This review presents an overview of the chief virulence determinants in S. aureus. More attention will be paid to staphyloxanthin, which could be a possible target for anti-virulence agents.

Assembly and Function of Seed Endophytes in Response to Environmental Stress

  • Yong-Lan Wang;Han-Bo Zhang
    • Journal of Microbiology and Biotechnology
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    • 제33권9호
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    • pp.1119-1129
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    • 2023
  • Seeds are colonized by diverse microorganisms that can improve the growth and stress resistance of host plants. Although understanding the mechanisms of plant endophyte-host plant interactions is increasing, much of this knowledge does not come from seed endophytes, particularly under environmental stress that the plant host grows to face, including biotic (e.g., pathogens, herbivores and insects) and abiotic factors (e.g., drought, heavy metals and salt). In this article, we first provided a framework for the assembly and function of seed endophytes and discussed the sources and assembly process of seed endophytes. Following that, we reviewed the impact of environmental factors on the assembly of seed endophytes. Lastly, we explored recent advances in the growth promotion and stress resistance enhancement of plants, functioning by seed endophytes under various biotic and abiotic stressors.

Relationship Between Plant Viral Encoded Suppressor to Post-transcriptional Gene Silencing and Elicitor to R Gene-specific Host Resistance

  • Park, Chang-Won;Feng Qu;Tao Ren;T. Jack Morris
    • The Plant Pathology Journal
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    • 제20권1호
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    • pp.22-29
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    • 2004
  • Many important horticultural and field crops are susceptible to virus infections or may possess a degree of resistance to some viruses, but become infected by others. Plant viruses enter cells through the presence of wounds, and replicate intracellularly small genomes that encode genes required for replication, cell-to-cell movement and encapsidation. There are numerous evidences from specific virus-host interactions to require the involvement of host factors and steps during viral replication cycle. However, viruses should deal with host defense responses either by general or specific mechanisms, targeting viral components or genome itself. On the other hand, the host plants have also adapted to defend themselves against viral attack by operating different lines of resistance responses. The defense-related interactions provide new insights into the complex molecular strategies for hosts for defense and counter-defense employed by viruses.

Topological implications of DNA tumor viral episomes

  • Eui Tae, Kim;Kyoung-Dong, Kim
    • BMB Reports
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    • 제55권12호
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    • pp.587-594
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    • 2022
  • A persistent DNA tumor virus infection transforms normal cells into cancer cells by either integrating its genome into host chromosomes or retaining it as an extrachromosomal entity called episome. Viruses have evolved mechanisms for attaching episomes to infected host cell chromatin to efficiently segregate the viral genome during mitosis. It has been reported that viral episome can affect the gene expression of the host chromosomes through interactions between viral episomes and epigenetic regulatory host factors. This mini review summarizes our current knowledge of the tethering sites of viral episomes, such as EBV, KSHV, and HBV, on host chromosomes analyzed by three-dimensional genomic tools.

Effect of Home-Host Country Psychic Distance (HHCPD) Perception of Chinese Tourists on Tourism Shopping Motivation and Fashion Brand Attitudes in Korea

  • Cui, Yu Hua;Choo, Ho Jung
    • 한국의류학회지
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    • 제42권1호
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    • pp.104-120
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    • 2018
  • The contribution of foreign tourist consumption on national economies is becoming increasingly important for many countries. This study examines the relationship of home-host country psychic distance (HHCPD), tourism shopping motivation and attitudes towards local and global fashion brands in host countries. Survey data from a sample of 500 Chinese tourists were collected at an international airport in Korea. The results reveal that all three key factors of HHCPD (economic, geographic and cultural distance) positively affect social shopping motivation. Moreover, only economic distance has a positive effect on commodity shopping motivation, while both cultural and economic distance positively influence souvenir shopping motivation. All three factors of tourism shopping motivation positively affect local fashion brand attitudes, while only commodity shopping motivation positively affects consumer attitudes towards global fashion brands. Thus, fashion marketers should trigger the shopping motivation of foreign tourists by maximising the psychic distance from their home in order to satisfy fashion-seeking tourists.

Virulence Factors and Stability of Coliphages Specific to Escherichia coli O157:H7 and to Various E. coli Infection

  • Kim, Eun-Jin;Chang, Hyun-Joo;Kwak, Soojin;Park, Jong-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제26권12호
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    • pp.2060-2065
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    • 2016
  • Characteristics of E. coli O157:H7-specific infection bacteriophages (O157 coliphages) and broad-host-range bacteriophages for other E. coli serotypes (broad-host coliphages) were compared. The burst sizes of the two groups ranged from 40 to 176 PFU/infected cell. Distributions of the virulence factors stx1, stx2, ehxA, and saa between the two groups were not differentiated. Broad-host-range coliphages showed lower stability at $70^{\circ}C$, in relation to O157 coliphages. However, O157 coliphages showed high acid and ethanol tolerance by reduction of only 22% and 11% phages, respectively, under pH 3 and 70% ethanol for 1 h exposure. Therefore, these results revealed that the O157 coliphages might be more stable under harsh environments, which might explain their effective infection of the acid-tolerant E. coli O157:H7.

브랜드 글로벌화 이미지와 원산지국가 브랜드 이미지가 소비자 행위에 미친 영향 (The Impact of Brand Internationalization Image and Country of Origin Brand Image on Consumer Behavior)

  • 전금염;유자양;손총영
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2023년도 제68차 하계학술대회논문집 31권2호
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    • pp.709-710
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    • 2023
  • Consumer attitudes and behaviors towards brands are not only related to the perception of corporate brand image but also to factors such as the image of the country of origin, the characteristics of the host country, and consumer individual traits. This article focuses on Chinese multinational companies and aims to study the impact of brand international image and country-of-origin brand image on consumer behavior. A model is constructed with brand international image and country-of-origin brand image as antecedent variables, host country characteristics and consumer traits as moderators, and consumer behavior as the outcome. This study employs a questionnaire survey method targeting foreign residents living in China as participants. The research findings reveal that during the internationalization process, both brand international image and country-of-origin brand image have a significant positive impact on consumer behavior, while host country characteristics and consumer traits play a moderating role. The conclusions of this research enrich the theoretical understanding of brand internationalization and explore the influencing factors of consumer behavior, providing a basis for decision-making for multinational company executives.

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Microbiome-Linked Crosstalk in the Gastrointestinal Exposome towards Host Health and Disease

  • Moon, Yuseok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제19권4호
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    • pp.221-228
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    • 2016
  • The gastrointestinal exposome represents the integration of all xenobiotic components and host-derived endogenous components affecting the host health, disease progression and ultimately clinical outcomes during the lifespan. The human gut microbiome as a dynamic exposome of commensalism continuously interacts with other exogenous exposome as well as host sentineling components including the immune and neuroendocrine circuit. The composition and diversity of the microbiome are established on the basis of the luminal environment (physical, chemical and biological exposome) and host surveillance at each part of the gastrointestinal lining. Whereas the chemical exposome derived from nutrients and other xenobiotics can influence the dynamics of microbiome community (the stability, diversity, or resilience), the microbiomes reciprocally alter the bioavailability and activities of the chemical exposome in the mucosa. In particular, xenobiotic metabolites by the gut microbial enzymes can be either beneficial or detrimental to the host health although xenobiotics can alter the composition and diversity of the gut microbiome. The integration of the mucosal crosstalk in the exposome determines the fate of microbiome community and host response to the etiologic factors of disease. Therefore, the network between microbiome and other mucosal exposome would provide new insights into the clinical intervention against the mucosal or systemic disorders via regulation of the gut-associated immunological, metabolic, or neuroendocrine system.

The Plant Cellular Systems for Plant Virus Movement

  • Hong, Jin-Sung;Ju, Ho-Jong
    • The Plant Pathology Journal
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    • 제33권3호
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    • pp.213-228
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    • 2017
  • Plasmodesmata (PDs) are specialized intercellular channels that facilitate the exchange of various molecules, including sugars, ribonucleoprotein complexes, transcription factors, and mRNA. Their diameters, estimated to be 2.5 nm in the neck region, are too small to transfer viruses or viral genomes. Tobacco mosaic virus and Potexviruses are the most extensively studied viruses. In viruses, the movement protein (MP) is responsible for the PD gating that allows the intercellular movement of viral genomes. Various host factors interact with MP to regulate complicated mechanisms related to PD gating. Virus replication and assembly occur in viral replication complex (VRC) with membrane association, especially in the endoplasmic reticulum. VRC have a highly organized structure and are highly regulated by interactions among the various host factors, proteins encoded by the viral genome, and the viral genome. Virus trafficking requires host machineries, such as the cytoskeleton and the secretory systems. MP facilitates the virus replication and movement process. Despite the current level of understanding of virus movement, there are still many unknown and complex interactions between virus replication and virus movement. While numerous studies have been conducted to understand plant viruses with regards to cell-to-cell movement and replication, there are still many knowledge gaps. To study these interactions, adequate research tools must be used such as molecular, and biochemical techniques. Without such tools, virologists will not be able to gain an accurate or detailed understanding of the virus infection process.