• Title/Summary/Keyword: Innate immune response

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Bone Marrow Progenitors and IL-2 Signaling Contribute to the Strain Differences of Kidney Innate Lymphoid Cells

  • Seungwon Ryu;Hye Young Kim
    • IMMUNE NETWORK
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    • v.23 no.2
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    • pp.15.1-15.17
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    • 2023
  • Innate lymphoid cells (ILCs) are critical immune-response mediators. Although they largely reside in mucosal tissues, the kidney also bears substantial numbers. Nevertheless, kidney ILC biology is poorly understood. BALB/c and C57BL/6 mice are known to display type-2 and type-1 skewed immune responses, respectively, but it is unclear whether this extends to ILCs. We show here that indeed, BALB/c mice have higher total ILCs in the kidney than C57BL/6 mice. This difference was particularly pronounced for ILC2s. We then showed that three factors contributed to the higher ILC2s in the BALB/c kidney. First, BALB/c mice demonstrated higher numbers of ILC precursors in the bone marrow. Second, transcriptome analysis showed that compared to C57BL/6 kidneys, the BALB/c kidneys associated with significantly higher IL-2 responses. Quantitative RT-PCR also showed that compared to C57BL/6 kidneys, the BALB/c kidneys expressed higher levels of IL-2 and other cytokines known to promote ILC2 proliferation and/or survival (IL-7, IL-33, and thymic stromal lymphopoietin). Third, the BALB/c kidney ILC2s may be more sensitive to the environmental signals than C57BL/6 kidney ILC2s since they expressed their transcription factor GATA3 and the IL-2, IL-7, and IL-25 receptors at higher levels. Indeed, they also demonstrated greater responsiveness to IL-2 than C57BL/6 kidney ILC2s, as shown by their greater STAT5 phosphorylation levels after culture with IL-2. Thus, this study demonstrates previously unknown properties of kidney ILC2s. It also shows the impact of mouse strain background on ILC2 behavior, which should be considered when conducting research on immune diseases with experimental mouse models.

Glucocorticoids Impair the 7α-Hydroxycholesterol-Enhanced Innate Immune Response

  • Yonghae Son;Bo-Young Kim;Miran Kim;Jaesung Kim;Ryuk Jun Kwon;Koanhoi Kim
    • IMMUNE NETWORK
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    • v.23 no.5
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    • pp.40.1-40.14
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    • 2023
  • Glucocorticoids suppress the vascular inflammation that occurs under hypercholesterolemia, as demonstrated in an animal model fed a high-cholesterol diet. However, the molecular mechanisms underlying these beneficial effects remain poorly understood. Because cholesterol is oxidized to form cholesterol oxides (oxysterols) that are capable of inducing inflammation, we investigated whether glucocorticoids affect the immune responses evoked by 7α-hydroxycholesterol (7αOHChol). The treatment of human THP-1 monocytic cells with dexamethasone (Dex) and prednisolone (Pdn) downregulated the expression of pattern recognition receptors (PRRs), such as TLR6 and CD14, and diminished 7αOHChol-enhanced response to FSL-1, a TLR2/6 ligand, and lipopolysaccharide, which interacts with CD14 to initiate immune responses, as determined by the reduced secretion of IL-23 and CCL2, respectively. Glucocorticoids weakened the 7αOHChol-induced production of CCL2 and CCR5 ligands, which was accompanied by decreased migration of monocytic cells and CCR5-expressing Jurkat T cells. Treatment with Dex or Pdn also reduced the phosphorylation of the Akt-1 Src, ERK1/2, and p65 subunits. These results indicate that both Dex and Pdn impair the expression of PRRs and their downstream products, chemokine production, and phosphorylation of signaling molecules. Collectively, glucocorticoids suppress the innate immune response and activation of monocytic cells to an inflammatory phenotype enhanced or induced by 7αOHChol, which may contribute to the anti-inflammatory effects in hypercholesterolemic conditions.

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Gene analysis of galectin-1, innate immune response gene, in olive flounder Paralichthys olivaceus at different developmental stage (넙치, Paralichthys olivaceus 발생단계별 galectin-1 유전자의 발현 분석)

  • Jang, Min Seok;Lee, Young Mee;Yang, Hyun;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul-Ji;Park, Jong-Won;Hwang, In Joon;Kim, Sung Yeon
    • Journal of fish pathology
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    • v.26 no.3
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    • pp.255-263
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    • 2013
  • The innate immune response is fundamental defense response of vertebrates and invertebrates. Especially, the innate immune response important for larvae that lack of resistance to infectious diseases in the early stages. Galectin is one of the kinds of lectin and presents in the fish mucous that involves innate immune response. Galectin have been studied from various fishing species, but expression analysis of galectin is still unclear during early developmental stage in olive flounder. In this study, we investigated gene expression of galectin-1 from various developmental stage and tissues. We excised several tissues including the muscle, fin, eye, gill, brain, stomach, intestine, kidney, spleen and liver from adult olive flounder and confirmed gene expression of galectin-1 using RT-PCR and quantitative real-time PCR. Expression of galectin-1 was significantly higher in muscle, stomach and intestinal tissue than other tissue in adult fish (5 and 29 months). Also, galectin-1 gene was detected from 0 DAH and gradually increased to 35 DAH and since then decreased after stomach development period. Induction of galectin-1 during the early developmental stage suggest that muscle, fin and eye tissue is formed and begins the secretion of galectin this period. In addition, increased expression levels at 35 DAH suggest that due to complete formation of stomach and intestine, increase of secretion and activation of enzyme. This study shows that expression of galectin-1 during early developmental stages and adult period in olive flounder and can be expect that galectin-1 play essental role in the innate immune system throughout the whole life time. Galectin-1 is primary barrier such as skin and digestive tissue against pathogen infection, also digestive tract developmental period is important for pathogen invasion can be expected that it will serve. Mass mortality due to the disease in seed production is continuing damage, therefore these result will be meaningful about infectious disease during early developmental stages as a basic data for the study.

Exposure to Environmental Endotoxin and Health Effects (환경 중의 엔도톡신 노출 및 건강에 미치는 영향)

  • Park, Ju-Hyeong
    • Journal of Environmental Health Sciences
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    • v.40 no.4
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    • pp.265-278
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    • 2014
  • Microbes such as bacteria, fungi, archaea, protists, and viruses are ubiquitous and people are exposed to them continuously. Endotoxin is a component of the outer membrane of Gram-negative bacteria and a potent proinflammaotry substance. When a person is exposed to environmental endotoxin, an innate immune response is initiated upon the initial recognition and this response produces various inflammatory mediators and recruits inflammatory cells to the exposed tissues. A purified chemical form of endotoxin is called lipopolysaccharide (LPS), and the lipid A portion of the molecule is a biologically active moiety. Exposure to endotoxin may result in various complex health effects depending on time, route, and dose of exposure, as well as host susceptibility. Gene-environment interactions play important roles in health effects of endotoxin exposure, e.g. development or aggravation of asthma. To accurately assess exposure to endotoxin in environmental or epidemiologic studies, methods of sampling, extraction, and analysis must be carefully selected since the selected methods may substantially affect analytical results and there is no internationally-agreed standard method to date. The lack of a standardized method hampers the establishment of exposure-response relationships. While an internationally-agreed health-based exposure limit does not exist, the Dutch Expert Committee on Occupational Safety recently recommended $90EU/m^3$ as a health-based occupational exposure limit. The current article reviews various scientific issues on how we measure environmental endotoxin and the health effects of endotoxin exposure.

The role of necroptosis in the treatment of diseases

  • Cho, Young Sik
    • BMB Reports
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    • v.51 no.5
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    • pp.219-224
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    • 2018
  • Necroptosis is an emerging form of programmed cell death occurring via active and well-regulated necrosis, distinct from apoptosis morphologically, and biochemically. Necroptosis is mainly unmasked when apoptosis is compromised in response to tumor necrosis factor alpha. Unlike apoptotic cells, which are cleared by macrophages or neighboring cells, necrotic cells release danger signals, triggering inflammation, and exacerbating tissue damage. Evidence increasingly suggests that programmed necrosis is not only associated with pathophysiology of disease, but also induces innate immune response to viral infection. Therefore, necroptotic cell death plays both physiological and pathological roles. Physiologically, necroptosis induce an innate immune response as well as premature assembly of viral particles in cells infected with virus that abrogates host apoptotic machinery. On the other hand, necroptosis per se is detrimental, causing various diseases such as sepsis, neurodegenerative diseases and ischemic reperfusion injury. This review discusses the signaling pathways leading to necroptosis, associated necroptotic proteins with target-specific inhibitors and diseases involved. Several studies currently focus on protective approaches to inhibiting necroptotic cell death. In cancer biology, however, anticancer drug resistance severely hampers the efficacy of chemotherapy based on apoptosis. Pharmacological switch of cell death finds therapeutic application in drug- resistant cancers. Therefore, the possible clinical role of necroptosis in cancer control will be discussed in brief.

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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    • v.29 no.12
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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.

Immune Responses against Marek's Disease Virus Infection (마렉병 바이러스 감염에 대한 면역 반응)

  • Jang, H.K.;Park, Y.M.;Cha, S.Y.;Park, J.B.
    • Korean Journal of Poultry Science
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    • v.35 no.3
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    • pp.225-240
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    • 2008
  • Marek's disease virus(MDV) is a highly cell-associated, lymphotropic $\alpha$-herpesvirus that causes paralysis and neoplastic disease in chickens. The disease has been controlled by vaccination which was provided the first evidence for a malignant cancer being controlled by an antiviral vaccine. Marek's disease pathogenesis is complex, involving cytolytic and latent infection of lymphoid cells and oncogenic transformation of $CD4^+$ T cells in susceptible chickens. MDV targets a number of different cell types during its life cycle. Lymphocytes play an essential role, although within them virus production is restricted and only virion are produced. Innate and adaptive immune responses develop in response to infection, but infection of lymphocytes results in immunosuppressive effects. Hence in MDV-infected birds, MDV makes its host more vulnerable to tumour development as well as to other pathogens. All chickens are susceptible to MDV infection, and vaccination is essential to protect the susceptible host from developing clinical disease. Nevertheless, MDV infects and replicates in vaccinated chickens, with the challenge virus being shed from the feather-follicle epithelium. The outcome of infection with MDV depends on a complex interplay of factors involving the MDV pathotype and the host genotype. Host factors that influence the course of MD are predominantly the responses of the innate and adaptive immune systems, and these are modulated by: age at infection and maturity of the immune system; vaccination status; the sex of the host; and various physiological factors.

Development of Vaccine Delivery System and Challenges (백신 전달기술 개발 동향과 과제)

  • Jung, Hyung-Il;Kim, Jung-Dong;Kim, Mi-Roo;Dangol, Manita
    • KSBB Journal
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    • v.25 no.6
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    • pp.497-506
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    • 2010
  • Vaccine is a protective clinical measure capable of persuading immune system against infectious agents. Vaccine can be categorized as live attenuated and inactivated. Live attenuated vaccines activate immunity similar to natural infection by replicating living organisms whereas inactivated vaccines are either whole cell vaccines, eliciting immune response by killed organisms,or subunit vaccines, stimulating immunity by non-replicating sub cellular parts. The components of vaccine play a critical role in deciding the immune response mediated by the vaccine. The innate immune responds against the antigen component. Adjuvants represent an importantcomponent of vaccine for enhancing the immunogenicity of the antigens. Subunit vaccines with isolated fractions of killed and recombinant antigens are mostly co-administered with adjuvants. The delivery system of the vaccine is another essential component to ensurethat vaccine is delivered to the right target with right dosage form. Furthermore, vaccine delivery system ensures that the desired immune response is achieved by manipulating the optimal interaction of vaccine and adjuvantwith the immune cell. The aforementioned components along with routes of administration of vaccine are the key elements of a successful vaccination procedure. Vaccines can be administered either orally or by parenteral routes. Many groups had made remarkable efforts for the development of new vaccine and delivery system. The emergence of new vaccine delivery system may lead to pursue the immunization goals with better clinical practices.

The Relationship between Mitochondria and NLRP3 Inflammasome

  • Lee, Hyun Ah;Na, Hee Sam;Chung, Jin
    • International Journal of Oral Biology
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    • v.42 no.3
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    • pp.85-90
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    • 2017
  • Mitochondria participate in various intracellular metabolic pathways such as generating intracellular ATP, synthesizing several essential molecules, regulating calcium homeostasis, and producing the cell's reactive oxygen species (ROS). Emerging studies have demonstrated newly discovered roles of mitochondria, which participate in the regulation of innate immune responses by modulating NLRP3 inflammasomes. Here, we review the recently proposed pathways to be involved in mitochondria-mediated regulation of inflammasome activation and inflammation: 1) mitochondrial ROS, 2) calcium mobilization, 3) nicotinamide adenine dinucleotide ($NAD^+$) reduction, 4) cardiolipin, 5) mitofusin, 6) mitochondrial DNA, 7) mitochondrial antiviral signaling protein. Furthermore, we highlight the significance of mitophagy as a negative regulator of mitochondrial damage and NLRP3 inflammasome activation, as potentially helpful therapeutic approaches which could potentially address uncontrolled inflammation.

Latest Comprehensive Knowledge of the Crosstalk between TLR Signaling and Mycobacteria and the Antigens Driving the Process

  • Kim, Jae-Sung;Kim, Ye-Ram;Yang, Chul-Su
    • Journal of Microbiology and Biotechnology
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    • v.29 no.10
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    • pp.1506-1521
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    • 2019
  • Tuberculosis, which is caused by Mycobacterium tuberculosis (Mtb), is among the most pressing worldwide problems. Mtb uniquely interacts with innate immune cells through various pattern recognition receptors. These interactions initiate several inflammatory pathways that play essential roles in controlling Mtb pathogenesis. Although the TLR signaling pathways have essential roles in numerous host's immune defense responses, the role of TLR signaling in the response to Mtb infection is still unclear. This review presents discussions on host-Mtb interactions in terms of Mtb-mediated TLR signaling. In addition, we highlight recent discoveries pertaining to these pathways that may help in new immunotherapeutic opportunities.