• 제목/요약/키워드: Innate defense

검색결과 120건 처리시간 0.029초

Protein-protein Interaction Network Analyses for Elucidating the Roles of LOXL2-delta72 in Esophageal Squamous Cell Carcinoma

  • Wu, Bing-Li;Zou, Hai-Ying;Lv, Guo-Qing;Du, Ze-Peng;Wu, Jian-Yi;Zhang, Pi-Xian;Xu, Li-Yan;Li, En-Min
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권5호
    • /
    • pp.2345-2351
    • /
    • 2014
  • Lysyl oxidase-like 2 (LOXL2), a member of the lysyl oxidase (LOX) family, is a copper-dependent enzyme that catalyzes oxidative deamination of lysine residues on protein substrates. LOXL2 was found to be overexpressed in esophageal squamous cell carcinoma (ESCC) in our previous research. We later identified a LOXL2 splicing variant LOXL2-delta72 and we overexpressed LOXL2-delta72 and its wild type counterpart in ESCC cells following microarray analyses. First, the differentially expressed genes (DEGs) of LOXL2 and LOXL2-delta72 compared to empty plasmid were applied to generate protein-protein interaction (PPI) sub-networks. Comparison of these two sub-networks showed hundreds of different proteins. To reveal the potential specific roles of LOXL2- delta72 compared to its wild type, the DEGs of LOXL2-delta72 vs LOXL2 were also applied to construct a PPI sub-network which was annotated by Gene Ontology. The functional annotation map indicated the third PPI sub-network involved hundreds of GO terms, such as "cell cycle arrest", "G1/S transition of mitotic cell cycle", "interphase", "cell-matrix adhesion" and "cell-substrate adhesion", as well as significant "immunity" related terms, such as "innate immune response", "regulation of defense response" and "Toll signaling pathway". These results provide important clues for experimental identification of the specific biological roles and molecular mechanisms of LOXL2-delta72. This study also provided a work flow to test the different roles of a splicing variant with high-throughput data.

Human Cytomegalovirus Inhibition of Interferon Signal Transduction

  • Daniel M. Miller
    • 미생물학회지
    • /
    • 제38권4호
    • /
    • pp.203-203
    • /
    • 2002
  • Cytomegalovirus (CMV), a beta-herpesvirus with worldwide distribution, exhibits host persistence, a distinguishing characteristic of all herpesviruses. This persistence is dependent upon restricted gene expression in infected cells as well as the ability of productively infected cells to escape from normal cell-mediated anti-viral immunosurveillance. Type I (IFN-α/β) and type II (IFN-γ) interferons are major components of the innate defense system against viral infection. They are potent inducers of MHC class I and II antigens and of antigen processing proteins. Additionally, IFNS mediate direct antiviral effects through induction effector molecules that block viral infection and replications such as 2′, 5-oligoadenylate synthetase (2, 5-OAS). IFNS function through activation of well-defined signal transduction pathways that involve phosphorylation of constituent proteins and ultimate formation of active transcription factors. Recent studies have shown that a number of diverse viruses, including CMV, EBV, HPV mumps and Ebola, are capable of inhibiting IFN-mediated signal transduction through a variety of mechanisms. As an example, CMV infection inhibits the ability of infected cells Is transcribe HLA class I and II antigens as well as the antiviral effector molecules 2, 5-OAS and MxA I. EMSA studies have shown that IFN-α and IFN-γ are unable to induce complete signal transduction in the presence of CMV infection, phenomena that are associated with specific decreases in JAKl and p48. Viral inhibition of IFN signal transduction represents a new mechanistic paradigm for increased viral survival, a paradigm predicting widespread consequences in the case of signal transduction factors common to multiple cytokine pathways.

Transcriptional Onset of Lysozyme Genes during Early Development in Olive Flounder (Paralichthys olivaceus)

  • Lee, Jang-Wook;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul-Ji;Park, Jong-Won;Kim, Kyung-Kil
    • 한국발생생물학회지:발생과생식
    • /
    • 제18권4호
    • /
    • pp.267-274
    • /
    • 2014
  • The immune system in teleost fish is not completely developed during embryonic and larval stages, therefore effective innate mechanisms is very important for survival in such an environment. However, the knowledge of the development of immune system assumed to be restricted. In many species, lysozymes have been considered as important genes of the first line immune defense. The early detection of lysozyme mRNA in previous reports, led to the investigation of its presence in oocytes. As a result, c-type lysozyme mRNA transcripts were detected in unfertilized oocytes indicating maternal transfer. Therefore, we investigated the expression patterns of lysozymes in flounder, including the matured oocyte. In our results, c-type lysozyme mRNA was first detected in unfertilized oocyte stage, observed the significantly decreased until hatching stage, and was significantly increased after hatching stage. On the other hand, g-type lysozyme mRNA transcripts were first detected at late neurula stage, and the mRNA level was significantly increased after 20 dph. It may be suggest that maternally supplied mRNAs are selectively degraded prior to the activation of embryonic transcription. This study will be help in understanding the maturation and onset of humoral immunity during development of olive flounder immune system.

Protein Kinase $C-{\alpha}$ Regulates Toll-like Receptor 4-Mediated Inducible Nitric Oxide Synthase Expression

  • Lee, Jin-Gu;Chin, Byung-Rho;Baek, Suk-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제34권1호
    • /
    • pp.28-35
    • /
    • 2008
  • Purpose: The nitric oxide (NO) release by inducible nitric oxide synthase (iNOS) is the key events in macrophage response to lipopolysaccharide (LPS) which is suggested to be a crucial mediator for inflammatory and innate immune responses. NO is an important mediator involved in many host defense action and may also lead to a harmful host response to bacterial infection. However, given the importance of iNOS in a variety of pathophysiological conditions, control of its expression and signaling events in response to LPS has been the subject of considerable investigation. Materials and Methods: The Raw264.7 macrophage cell line was used to observe LPS-stimulated iNOS expression. The expression of iNOS is observed by Western blot analysis and real-time RT-PCR. Protein kinase C $(PKC)-{\alpha}$ overexpressing Raw264.7 cells are established to determine the involvement of $PKC-{\alpha}$ in LPS-mediated iNOS expression. $NF-{\kappa}B$ activity is measured by $I{\kappa}B{\alpha}$ degradation and $NF-{\kappa}B$ luciferase activity assay. Results: We found that various PKC isozymes regulate LPS-induced iNOS expression at the transcriptional and translational levels. The involvement of $PKC-{\alpha}$ in LPS-mediated iNOS induction was further confirmed by increased iNOS expression in $PKC-{\alpha}$ overexpressing cells. $NF-{\kappa}B$ dependent transactivation by LPS was observed and $PKC-{\alpha}$ specific inhibitory peptide abolished this activation, indicating that $NF-{\kappa}B$ activation is dependent on $PKC-{\alpha}$. Conclusion: Our data suggests that $PKC-{\alpha}$ is involved in LPS-mediated iNOS expression and that its downstream target is $NF-{\kappa}B$. Although $PKC-{\alpha}$ is a crucial mediator in the iNOS regulation, other PKC isozymes may contribute LPS-stimulated iNOS expression. This finding is needed to be elucidated in further study.

Variable localization of Toll-like receptors in human fallopian tube epithelial cells

  • Amjadi, Fatemehsadat;Zandieh, Zahra;Salehi, Ensieh;Jafari, Reza;Ghasemi, Nasrin;Aflatoonian, Abbas;Fazeli, Alireza;Aflatoonian, Reza
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제45권1호
    • /
    • pp.1-9
    • /
    • 2018
  • Objective: To determine the localization, expression, and function of Toll-like receptors (TLRs) in fallopian tube epithelial cells. Methods: The localization of TLRs in fallopian tube epithelial cells was investigated by immunostaining. Surprisingly, the intensity of staining was not equal in the secretory and ciliated cells. After primary cell culture of fallopian tube epithelial cells, ring cloning was used to isolate colonies of ciliated epithelial cells, distinct from non-ciliated epithelial cells. The expression of TLRs 1-10 was examined by quantitative real-time polymerase chain reaction, and protein localization was confirmed by immunostaining. The function of the TLRs was determined by interleukin (IL)-6 and IL-8 production in response to TLR2, TLR3, TLR5, TLR7, and TLR9 ligands. Results: Fallopian tube epithelial cells expressed TLRs 1-10 in a cell-type-specific manner. Exposing fallopian tube epithelial cells to TLR2, TLR3, TLR5, TLR7, and TLR9 agonists induced the secretion of proinflammatory cytokines such as IL-6 and IL-8. Conclusion: Our findings suggest that TLR expression in the fallopian tubes is cell-type-specific. According to our results, ciliated cells may play more effective role than non-ciliated cells in the innate immune defense of the fallopian tubes, and in interactions with gametes and embryos.

Isolation and expression analysis of stimulator of interferon gene from olive flounder, Paralichthys olivaceus

  • Ma, Jeong-In;Kang, Sunhye;Jeong, Hyung-Bok;Lee, Jehee
    • Fisheries and Aquatic Sciences
    • /
    • 제21권3호
    • /
    • pp.5.1-5.8
    • /
    • 2018
  • Stimulator of interferon gene (STING) is induced by various inflammatory agents, such as lipopolysaccharide and microbial pathogens, including virus and bacteria. In this study, we obtained a full-length cDNA of a STING homolog from olive flounder using rapid amplification of cDNA ends PCR technique. The full-length cDNA of Paralichthys olivaceus STING (PoSTING) was 1442 bp in length and contained a 1209-bp open reading frame that translated into 402 amino acids. The theoretical molecular mass of the predicted protein sequence was 45.09 kDa. In the PoSTING protein, three transmembrane domains and the STING superfamily domain were identified as characteristic features. Quantitative real-time PCR revealed that PoSTING expressed in all the tissues analyzed, but showed the highest level in the spleen. Temporal expression analysis examined the significantly upregulated expression of PoSTING mRNA after viral hemorrhagic septicemia virus (VHSV) stimulation. In contrast, no significant changes in the PoSTING expression were detected in Edwardsiella tarda-challenged group compared to the un-injected control. The expression of P. olivaceus type I interferon (PoIFN-I) was also highly upregulated upon VHSV challenge. These results suggest that STING might be involved in the essential immune defense against viral infection together with the activation of IFN-I in olive flounder.

MAP Kinase-Mediated Negative Regulation of Symbiotic Nodule Formation in Medicago truncatula

  • Ryu, Hojin;Laffont, Carole;Frugier, Florian;Hwang, Ildoo
    • Molecules and Cells
    • /
    • 제40권1호
    • /
    • pp.17-23
    • /
    • 2017
  • Mitogen-activated protein kinase (MAPK) signaling cascades play critical roles in various cellular events in plants, including stress responses, innate immunity, hormone signaling, and cell specificity. MAPK-mediated stress signaling is also known to negatively regulate nitrogen-fixing symbiotic interactions, but the molecular mechanism of the MAPK signaling cascades underlying the symbiotic nodule development remains largely unknown. We show that the MtMKK5-MtMPK3/6 signaling module negatively regulates the early symbiotic nodule formation, probably upstream of ERN1 (ERF Required for Nodulation 1) and NSP1 (Nod factor Signaling Pathway 1) in Medicago truncatula. The overexpression of MtMKK5 stimulated stress and defense signaling pathways but also reduced nodule formation in M. truncatula roots. Conversely, a MAPK specific inhibitor, U0126, enhanced nodule formation and the expression of an early nodulation marker gene, MtNIN. We found that MtMKK5 directly activates MtMPK3/6 by phosphorylating the TEY motif within the activation loop and that the MtMPK3/6 proteins physically interact with the early nodulation-related transcription factors ERN1 and NSP1. These data suggest that the stress signaling-mediated MtMKK5/MtMPK3/6 module suppresses symbiotic nodule development via the action of early nodulation transcription factors.

Human Cytomegalovirus Inhibition of Interferon Signal Transduction

  • Miller, Daniel M.;Cebulla, Colleen M.;Sedmak, Daniel D.
    • Journal of Microbiology
    • /
    • 제38권4호
    • /
    • pp.203-208
    • /
    • 2000
  • Cytomegalovirus (CMV), a beta-herpesvirus with worldwide distribution, exhibits host persistence, a distinguishing characteristic of all herpesviruses. This persistence is dependent upon restricted gene expression in infected cells as well as the ability of productively infected cells to escape from normal cell-mediated anti-viral immunosurveillance. Type I (IFN-$\alpha$/$\beta$) and type II (IFN-γ) interferons are major components of the innate defense system against viral infection. They are potent inducers of MHC class I and II antigens and of antigen processing proteins. Additionally, IFNS mediate direct antiviral effects through induction effector molecules that block viral infection and replications such as 2', 5-oligoadenylate synthetase (2, 5-OAS). IFNS function through activation of well-defined signal transduction pathways that involve phosphorylation of constituent proteins and ultimate formation of active transcription factors. Recent studies have shown that a number of diverse viruses, including CMV, EBV, HPV mumps and Ebola, are capable of inhibiting IFN-mediated signal transduction through a variety of mechanisms. As an example, CMV infection inhibits the ability of infected cells Is transcribe HLA class I and II antigens as well as the antiviral effector molecules 2, 5-OAS and MxA I. EMSA studies have shown that IFN-$\alpha$ and IFN-γ are unable to induce complete signal transduction in the presence of CMV infection, phenomena that are associated with specific decreases in JAKl and p48. Viral inhibition of IFN signal transduction represents a new mechanistic paradigm for increased viral survival, a paradigm predicting widespread consequences in the case of signal transduction factors common to multiple cytokine pathways.

  • PDF

Distinct Features of Brain-Resident Macrophages: Microglia and Non-Parenchymal Brain Macrophages

  • Lee, Eunju;Eo, Jun-Cheol;Lee, Changjun;Yu, Je-Wook
    • Molecules and Cells
    • /
    • 제44권5호
    • /
    • pp.281-291
    • /
    • 2021
  • Tissue-resident macrophages play an important role in maintaining tissue homeostasis and innate immune defense against invading microbial pathogens. Brain-resident macrophages can be classified into microglia in the brain parenchyma and non-parenchymal brain macrophages, also known as central nervous system-associated or border-associated macrophages, in the brain-circulation interface. Microglia and non-parenchymal brain macrophages, including meningeal, perivascular, and choroid plexus macrophages, are mostly produced during embryonic development, and maintained their population by self-renewal. Microglia have gained much attention for their dual roles in the maintenance of brain homeostasis and the induction of neuroinflammation. In particular, diverse phenotypes of microglia have been increasingly identified under pathological conditions. Single-cell phenotypic analysis revealed that microglia are highly heterogenous and plastic, thus it is difficult to define the status of microglia as M1/M2 or resting/activated state due to complex nature of microglia. Meanwhile, physiological function of non-parenchymal brain macrophages remain to be fully demonstrated. In this review, we have summarized the origin and signatures of brain-resident macrophages and discussed the unique features of microglia, particularly, their phenotypic polarization, diversity of subtypes, and inflammasome responses related to neurodegenerative diseases.

Galectin-1 from redlip mullet Liza haematocheilia: identification, immune responses, and functional characterization as pattern recognition receptors (PRRs) in host immune defense system

  • Chaehyeon Lim;Hyukjae Kwon;Jehee Lee
    • Fisheries and Aquatic Sciences
    • /
    • 제25권11호
    • /
    • pp.559-571
    • /
    • 2022
  • Galectins, a family of ß-galactoside-binding lectins, have emerged as soluble mediators in infected cells and pattern recognition receptors (PRRs) responsible for evoking and regulating innate immunity. The present study aimed to evaluate the role of galectin-1 in the host immune response of redlip mullet (Liza haematocheilia). We established a cDNA database for redlip mullet, and the cDNA sequence of galectin-1 (LhGal-1) was characterized. In silico analysis was performed, and the spatial and temporal expression patterns in gills and blood in response to lipopolysaccharide polyinosinic:polycytidylic acid, and Lactococcus garvieae were estimated via quantitative real-time PCR. Functional assays were conducted using recombinant protein to investigate carbohydrate binding, bacterial binding, and bacterial agglutination activity. LhGal-1 was composed of 135 amino acids. Conserved motifs (H-NPR, -N- and -W-E-R) within the carbohydrate recognition domain were found in LhGal-1. The tissue distribution revealed that the healthy stomach expressed high levels of LhGal-1. The temporal monitoring of LhGal-1 mRNA expression in the gill and blood showed its significant upregulation in response to immune challenges with different stimulants. rLhGal-1 exhibited binding activity in response to carbohydrates and bacteria. Moreover, the agglutination of rLhGal-1 against Escherichia coli was observed. Collectively, our findings suggest that LhGal-1 may function as a PRR in redlip mullet. Furthermore, LhGal-1 can be considered a significant gene to play a protective role in redlip mullet immune system.