• Title/Summary/Keyword: cell infection

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Emerging roles of neutrophils in immune homeostasis

  • Lee, Mingyu;Lee, Suh Yeon;Bae, Yoe-Sik
    • BMB Reports
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    • 제55권10호
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    • pp.473-480
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    • 2022
  • Neutrophils, the most abundant innate immune cells, play essential roles in the innate immune system. As key innate immune cells, neutrophils detect intrusion of pathogens and initiate immune cascades with their functions; swarming (arresting), cytokine production, degranulation, phagocytosis, and projection of neutrophil extracellular trap. Because of their short lifespan and consumption during immune response, neutrophils need to be generated consistently, and generation of newborn neutrophils (granulopoiesis) should fulfill the environmental/systemic demands for training in cases of infection. Accumulating evidence suggests that neutrophils also play important roles in the regulation of adaptive immunity. Neutrophil-mediated immune responses end with apoptosis of the cells, and proper phagocytosis of the apoptotic body (efferocytosis) is crucial for initial and post resolution by producing tolerogenic innate/adaptive immune cells. However, inflammatory cues can impair these cascades, resulting in systemic immune activation; necrotic/pyroptotic neutrophil bodies can aggravate the excessive inflammation, increasing inflammatory macrophage and dendritic cell activation and subsequent TH1/TH17 responses contributing to the regulation of the pathogenesis of autoimmune disease. In this review, we briefly introduce recent studies of neutrophil function as players of immune response.

류마티스 관절염에서 NLRP3 인플라마좀의 역할 (Role of NLRP3 Inflammasome in Rheumatoid Arthritis)

  • 김현진;정수현;이준호;김대용;양갑식
    • 대한융합한의학회지
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    • 제4권1호
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    • pp.5-11
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    • 2022
  • Objectives: Inflammasomes are molecular platforms that are generated inside cytoplasmic compartments. The objective is to mediate immunological responses of the host to cell damage and infection. Caspase-1 is triggered by inflammasome to generate interleukin-1𝛽 (IL-1𝛽), an inflammatory cytokine, and pyroptosis, an inflammatory form of apoptosis. Methods: In the past two decades, scientists have uncovered several inflammasomes. The most research has been conducted on NLRP3 inflamamsomes, whose activity can be stimulated by a variety of induction factors. However, the unregulated activation of NLRP3 inflammasomes is also a role in the etiology of several human disorders. Previous research has demonstrated that NLRP3 inflammasomes have a significant role in the innate and acquired immune systems, as well as in the prevalence of joint illnesses such rheumatoid arthritis. Conclusion: Within the scope of this review, we will present a brief overview of the biological features of NLRP3 inflamamsomes as well as a description of the underlying mechanisms governing activation and regulation. In particular, we explore the function of inflammasomes in the development of rheumatoid arthritis as well as the promise of recently identified medicines that target inflamasomes.

Solitary Keratoacanthoma at the Recipient Site of a Full-Thickness Skin Graft: A Case Report and Review of the Literature

  • Jeong Ho Kim;Sang-Hoon Lee;Seung-Phil Hong;Jiye Kim;Sug Won Kim
    • Archives of Plastic Surgery
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    • 제50권1호
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    • pp.59-62
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    • 2023
  • A 57-year-old man presented with a pigmented papule, 0.4 cm in diameter, on the left lower eyelid. Skin biopsy revealed a basal cell carcinoma, which was excised through a wide excision followed by a full-thickness skin graft (FTSG). Two weeks after the surgery, an erythematous nodule developed in the lower margin of the graft recipient site. The nodule size increased rapidly over 2 weeks, becoming dome-shaped with a central hyperkeratotic plug. A diagnosis of keratoacanthoma (KA) was made, and surgical excision was performed. Histological findings revealed a large, well-differentiated squamous tumor with a central keratin-filled crater and buttress. The human papilloma virus (HPV) genotyping results were negative. Risk factors for KA include trauma, old age, exposure to ultraviolet (UV) radiation, immunosuppression, and HPV infection. KA has most often been reported to develop at the donor site. Although the pathogenesis of KA is unclear, trauma is believed to act as a second insult to a preceding oncogenic insult, such as exposure to UV radiation, resulting in a koebnerization. Herein, we report a case of solitary KA at a FTSG recipient site. This report presents information that may provide guidance during dermatologic surgeries.

Molecular epidemiological survey of pathogenic trypanosomes in naturally infected cattle in northern Côte d'ivoire

  • Jean-Yves Ekra;Edouard K. N'Goran;Leonard E.G. Mboera;Biego Guillaume Gragnon;Koco Rita Nadege Assovie;Eliakunda Michael Mafie
    • Parasites, Hosts and Diseases
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    • 제61권2호
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    • pp.127-137
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    • 2023
  • Bovine trypanosomiasis is a significant health concern for livestock intensification in Côte d'Ivoire. This study aimed to determine the prevalence and distribution of pathogenic trypanosomes and identify the most infected cattle breed in northern Côte d'Ivoire. We examined 700 cattle and found that polymerase chain reaction (PCR) was more sensitive (12.3%) than microscopic observation (5.6%). Among the trypanosome species detected in naturally infected cattle, Trypanosoma vivax was 7.3%, Trypanosoma simiae tsavo was 6.7%, and Trypanosoma congolense was 0.4%. The overall prevalence of trypanosome infection in all cattle breeds was 12.3%, while the prevalence in individual breeds was 14.8%, 7.3%, 10.6%, and 12.3% for N'Dama, Baoule, Zebu, and Mere breed, respectively. The infected animals had low packed cell volume, influencing the prevalence. Our findings indicate that bovine trypanosomes are prevalent in Côte d'Ivoire, and their prevalence varies by region and breed. These pathogens include T. vivax, T. simiae tsavo, and T. congolense.

Characterization of Immune Cells From the Lungs of Patients With Chronic Non-Tuberculous Mycobacteria or Pseudomonas aeruginosa Infection

  • Alan R. Schenkel;John D. Mitchell;Carlyne D. Cool;Xiyuan Bai;Steve Groshong;Tilman Koelsch;Deepshikha Verma;Diane Ordway;Edward D. Chan
    • IMMUNE NETWORK
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    • 제22권3호
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    • pp.27.1-27.13
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    • 2022
  • Little is known of the lung cellular immunophenotypes in patients with non-tuberculous mycobacterial lung disease (NTM-LD). Flow-cytometric analyses for the major myeloid and lymphoid cell subsets were performed in less- and more-diseased areas of surgically resected lungs from six patients with NTM-LD and two with Pseudomonas aeruginosa lung disease (PsA-LD). Lymphocytes, comprised mainly of NK cells, CD4+ and CD8+ T cells, and B cells, accounted for ~60% of all leukocytes, with greater prevalence of T and B cells in more-diseased areas. In contrast, fewer neutrophils were found with decreased number in more-diseased areas. Compared to NTM-LD, lung tissues from patients with PsA-LD demonstrated relatively lower numbers of T and B lymphocytes but similar numbers of NK cells. While this study demonstrated a large influx of lymphocytes into the lungs of patients with chronic NTM-LD, further analyses of their phenotypes are necessary to determine the significance of these findings.

Evaluation of Immunoproteasome-Specific Proteolytic Activity Using Fluorogenic Peptide Substrates

  • Sumin Kim;Seo Hyeong Park;Won Hoon Choi;Min Jae Lee
    • IMMUNE NETWORK
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    • 제22권3호
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    • pp.28.1-28.11
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    • 2022
  • The 26S proteasome irreversibly hydrolyzes polyubiquitylated substrates to maintain protein homeostasis; it also regulates immune responses by generating antigenic peptides. An alternative form of the 26S proteasome is the immunoproteasome, which contains substituted catalytic subunits (β1i/PSMB9, β2i/PSMB10, and β5i/PSMB8) instead of constitutively expressed counterparts (β1/PSMB6, β2/PSMB7, and β5/PSMB5). The immunoproteasome expands the peptide repertoire presented on MHC class I molecules. However, how its activity changes in this context is largely elusive, possibly due to the lack of a standardized methodology to evaluate its specific activity. Here, we describe an assay protocol that measures the immunoproteasome activity of whole-cell lysates using commercially available fluorogenic peptide substrates. Our results showed that the most accurate assessment of immunoproteasome activity could be achieved by combining β5i-targeting substrate Ac-ANW-AMC and immunoproteasome inhibitor ONX-0914. This simple and reliable protocol may contribute to future studies of immunoproteasomes and their pathophysiological roles during viral infection, inflammation, and tumorigenesis.

The Role of Plasmacytoid Dendritic Cells in Gut Health

  • Hye-Yeon Won;Ju-Young Lee;Dahye Ryu;Hyung-Taek Kim;Sun-Young Chang
    • IMMUNE NETWORK
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    • 제19권1호
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    • pp.6.1-6.14
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    • 2019
  • Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.

IL-17-Producing Cells in Tumor Immunity: Friends or Foes?

  • Da-Sol Kuen;Byung-Seok Kim;Yeonseok Chung
    • IMMUNE NETWORK
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    • 제20권1호
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    • pp.6.1-6.20
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    • 2020
  • IL-17 is produced by RAR-related orphan receptor gamma t (RORγt)-expressing cells including Th17 cells, subsets of γδT cells and innate lymphoid cells (ILCs). The biological significance of IL-17-producing cells is well-studied in contexts of inflammation, autoimmunity and host defense against infection. While most of available studies in tumor immunity mainly focused on the role of T-bet-expressing cells, including cytotoxic CD8+ T cells and NK cells, and their exhaustion status, the role of IL-17-producing cells remains poorly understood. While IL-17-producing T-cells were shown to be anti-tumorigenic in adoptive T-cell therapy settings, mice deficient in type 17 genes suggest a protumorigenic potential of IL-17-producing cells. This review discusses the features of IL-17-producing cells, of both lymphocytic and myeloid origins, as well as their suggested pro- and/or anti-tumorigenic functions in an organ-dependent context. Potential therapeutic approaches targeting these cells in the tumor microenvironment will also be discussed.

Lactobacillus Persisters Formation and Resuscitation

  • Hyein Kim;Sejong Oh;Sooyeon Song
    • Journal of Microbiology and Biotechnology
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    • 제34권4호
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    • pp.854-862
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    • 2024
  • Lactobacillus is a commonly used probiotic, and many researchers have focused on its stress response to improve its functionality and survival. However, studies on persister cells, dormant cells that aid bacteria in surviving general stress, have focused on pathogenic bacteria that cause infection, not Lactobacillus. Thus, understanding Lactobacillus persister cells will provide essential clues for understanding how Lactobacillus survives and maintains its function under various environmental conditions. We treated Lactobacillus strains with various antibiotics to determine the conditions required for persister formation using kill curves and transmission electron microscopy. In addition, we observed the resuscitation patterns of persister cells using single-cell analysis. Our results show that Lactobacillus creates a small population of persister cells (0.0001-1% of the bacterial population) in response to beta-lactam antibiotics such as ampicillin and amoxicillin. Moreover, only around 0.5-1% of persister cells are heterogeneously resuscitated by adding fresh media; the characteristics are typical of persister cells. This study provides a method for forming and verifying the persistence of Lactobacillus and demonstrates that antibiotic-induced Lactobacillus persister cells show characteristics of dormancy, sensitivity of antibiotics, same as exponential cells, multi-drug tolerance, and resuscitation, which are characteristics of general persister cells. This study suggests that the mechanisms of formation and resuscitation may vary depending on the characteristics, such as the membrane structure of the bacterial species.

Immunoinformatics studies and design of a novel multi-epitope peptide vaccine against Toxoplasma gondii based on calcium-dependent protein kinases antigens through an in-silico analysis

  • Ali Dalir Ghaffari;Fardin Rahimi
    • Clinical and Experimental Vaccine Research
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    • 제13권2호
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    • pp.146-154
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    • 2024
  • Purpose: Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5. Materials and Methods: Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted. Results: The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite. Conclusion: In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.