scholarly journals Type I-E CRISPR-Cas system as an immune system in a eukaryote

2018 ◽  
Author(s):  
Devashish Rath ◽  
Lina Amlinger ◽  
Gargi Bindal ◽  
Magnus Lundgren
Keyword(s):  
Nucleic Acid ◽  
Dna Cleavage ◽  
Basic Research ◽  
Type I ◽  
Crispr Locus ◽  
Adaptive Immune ◽  
Research Platform ◽  
Adaptive Immune Systems ◽  
Cas Proteins

AbstractDefense against viruses and other mobile genetic elements (MGEs) is important in many organisms. The CRISPR-Cas systems found in bacteria and archaea constitute adaptive immune systems that acquire the ability to recognize MGEs by introducing nucleic acid samples, spacers, in the CRISPR locus. The CRISPR is transcribed and processed, and the produced CRISPR RNAs guide Cas proteins to degrade matching nucleic acid sequences. No CRISPR-Cas system is found to occur naturally in eukaryotic cells but here we demonstrate interference by type I-E CRISPR-Cas system from Escherichia coli introduced in Saccharomyces cerevisiae. The designed CRISPR arrays are properly expressed and processed in S. cerevisiae. Targeted plasmids display reduced transformation efficiency, indicative of DNA cleavage. Unlike e.g. Cas9-based systems, which can be used to inactivate MGEs in eukaryotes by introducing specific mutations, type I-E systems processively degrade the target. The type I-E system thus allows for defense without knowledge of MGE gene function. The reconstituted CRISPR-Cas system in S. cerevisiae can also function as a basic research platform for testing the role of various factors in the interference process.

scholarly journals CRISPR-Cas: biology, mechanisms and relevance

2016 ◽  
Vol 371 (1707) ◽  
pp. 20150496 ◽  
Author(s):  
Frank Hille ◽  
Emmanuelle Charpentier
Keyword(s):  
Dna Sequences ◽  
Adaptive Immune System ◽  
Crispr Locus ◽  
Biochemical Processes ◽  
Adaptive Immune ◽  
Physiological Properties ◽  
Target Dna ◽  
Associated Proteins ◽  
Cas Proteins

Prokaryotes have evolved several defence mechanisms to protect themselves from viral predators. Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) display a prokaryotic adaptive immune system that memorizes previous infections by integrating short sequences of invading genomes—termed spacers—into the CRISPR locus. The spacers interspaced with repeats are expressed as small guide CRISPR RNAs (crRNAs) that are employed by Cas proteins to target invaders sequence-specifically upon a reoccurring infection. The ability of the minimal CRISPR-Cas9 system to target DNA sequences using programmable RNAs has opened new avenues in genome editing in a broad range of cells and organisms with high potential in therapeutical applications. While numerous scientific studies have shed light on the biochemical processes behind CRISPR-Cas systems, several aspects of the immunity steps, however, still lack sufficient understanding. This review summarizes major discoveries in the CRISPR-Cas field, discusses the role of CRISPR-Cas in prokaryotic immunity and other physiological properties, and describes applications of the system as a DNA editing technology and antimicrobial agent. This article is part of the themed issue ‘The new bacteriology’.

scholarly journals Role of the Innate Immunity Signaling Pathway in the Pathogenesis of Sjögren’s Syndrome

2021 ◽  
Vol 22 (6) ◽  
pp. 3090
Author(s):  
Toshimasa Shimizu ◽  
Hideki Nakamura ◽  
Atsushi Kawakami
Keyword(s):  
Immune Responses ◽  
Sjögren's Syndrome ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Adaptive Immune ◽  
Sjögren‘S Syndrome

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by chronic inflammation of the salivary and lacrimal glands and extra-glandular lesions. Adaptive immune response including T- and B-cell activation contributes to the development of SS. However, its pathogenesis has not yet been elucidated. In addition, several patients with SS present with the type I interferon (IFN) signature, which is the upregulation of the IFN-stimulated genes induced by type I IFN. Thus, innate immune responses including type I IFN activity are associated with SS pathogenesis. Recent studies have revealed the presence of activation pattern recognition receptors (PRRs) including Toll-like receptors, RNA sensor retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, and inflammasomes in infiltrating and epithelial cells of the salivary glands among patients with SS. In addition, the activation of PRRs via the downstream pathway such as the type I IFN signature and nuclear factor kappa B can directly cause organ inflammation, and it is correlated with the activation of adaptive immune responses. Therefore, this study assessed the role of the innate immune signal pathway in the development of inflammation and immune abnormalities in SS.

scholarly journals CRISPR-Cas immunity repressed by a biofilm-activating pathway inPseudomonas aeruginosa

2019 ◽  
Author(s):  
Adair L. Borges ◽  
Bardo Castro ◽  
Sutharsan Govindarajan ◽  
Tina Solvik ◽  
Veronica Escalante ◽  
...  
Keyword(s):  
Genetic Screen ◽  
Type I ◽  
Two Component System ◽  
Component System ◽  
Forward Genetic Screen ◽  
Immune Systems ◽  
Adaptive Immune ◽  
Biofilm Production ◽  
Two Component ◽  
Adaptive Immune Systems

CRISPR-Cas systems are adaptive immune systems that protect bacteria from bacteriophage (phage) infection. To provide immunity, RNA-guided protein surveillance complexes recognize foreign nucleic acids, triggering their destruction by Cas nucleases. While the essential requirements for immune activity are well understood, the physiological cues that regulate CRISPR-Cas expression are not. Here, a forward genetic screen identifies a two-component system (KinB/AlgB), previously characterized in regulatingPseudomonas aeruginosavirulence and biofilm establishment, as a regulator of the biogenesis and activity of the Type I-F CRISPR-Cas system. Downstream of the KinB/AlgB system, activators of biofilm production AlgU (a σEorthologue) and AlgR, act as repressors of CRISPR-Cas activity during planktonic and surface-associated growth. AmrZ, another biofilm activator, functions as a surface-specific repressor of CRISPR-Cas immunity.Pseudomonasphages and plasmids have taken advantage of this regulatory scheme, and carry hijacked homologs of AmrZ, which are functional CRISPR-Cas repressors. This suggests that while CRISPR-Cas regulation may be important to limit self-toxicity, endogenous repressive pathways represent a vulnerability for parasite manipulation.

Neuroimmunology for the Non-Immunologist

2019 ◽  
pp. 2-20
Author(s):  
Bibiana Bielekova
Keyword(s):  
Immune System ◽  
Antigen Presentation ◽  
Immune Tolerance ◽  
Short Introduction ◽  
Immune Synapse ◽  
Immune Systems ◽  
Adaptive Immune ◽  
Adaptive Immune Systems ◽  
Autoimmune Phenomena

The chapter begins with a short introduction to the components of the immune system, outlining both the innate and adaptive components. It discusses the role of the immune system in protecting against infections and abnormal tissues. It describes the concepts of self-antigens, antigen presentation, and immune synapse. It then examines immune tolerance and the differing functions and capacities of the innate and adaptive immune systems. Finally, the chapter considers infections and autoimmune phenomena and how the immune system responds to these challenges.

scholarly journals Structural basis for inhibition of the type I-F CRISPR–Cas surveillance complex by AcrIF4, AcrIF7 and AcrIF14

2020 ◽  
Author(s):  
Clinton Gabel ◽  
Zhuang Li ◽  
Heng Zhang ◽  
Leifu Chang
Keyword(s):  
Genome Editing ◽  
Conformational Changes ◽  
Structural Basis ◽  
Type I ◽  
Structural Detail ◽  
Immune Systems ◽  
Helical Bundle ◽  
Adaptive Immune ◽  
Target Dna ◽  
Adaptive Immune Systems

Abstract CRISPR–Cas systems are adaptive immune systems in bacteria and archaea to defend against mobile genetic elements (MGEs) and have been repurposed as genome editing tools. Anti-CRISPR (Acr) proteins are produced by MGEs to counteract CRISPR–Cas systems and can be used to regulate genome editing by CRISPR techniques. Here, we report the cryo-EM structures of three type I-F Acr proteins, AcrIF4, AcrIF7 and AcrIF14, bound to the type I-F CRISPR–Cas surveillance complex (the Csy complex) from Pseudomonas aeruginosa. AcrIF4 binds to an unprecedented site on the C-terminal helical bundle of Cas8f subunit, precluding conformational changes required for activation of the Csy complex. AcrIF7 mimics the PAM duplex of target DNA and is bound to the N-terminal DNA vise of Cas8f. Two copies of AcrIF14 bind to the thumb domains of Cas7.4f and Cas7.6f, preventing hybridization between target DNA and the crRNA. Our results reveal structural detail of three AcrIF proteins, each binding to a different site on the Csy complex for inhibiting degradation of MGEs.

scholarly journals The MicroRNA miR-155 Is Essential in Fibrosis

2019 ◽  
Vol 5 (1) ◽  
pp. 23 ◽  
Author(s):  
Mousa Eissa ◽  
Carol Artlett
Keyword(s):  
Collagen Synthesis ◽  
Regulation Of Gene Expression ◽  
Viable Option ◽  
Adaptive Immune ◽  
Biological Interest ◽  
Integral Role ◽  
Fibrotic Disorders ◽  
Adaptive Immune Systems ◽  
Tgf Β1

The function of microRNAs (miRNAs) during fibrosis and the downstream regulation of gene expression by these miRNAs have become of great biological interest. miR-155 is consistently upregulated in fibrotic disorders, and its ablation downregulates collagen synthesis. Studies demonstrate the integral role of miR-155 in fibrosis, as it mediates TGF-β1 signaling to drive collagen synthesis. In this review, we summarize recent findings on the association between miR-155 and fibrotic disorders. We discuss the cross-signaling between macrophages and fibroblasts that orchestrates the upregulation of collagen synthesis mediated by miR-155. As miR-155 is involved in the activation of the innate and adaptive immune systems, specific targeting of miR-155 in pathologic cells that make excessive collagen could be a viable option before the depletion of miR-155 becomes an attractive antifibrotic approach.

scholarly journals Type I Interferons Mediate the Innate Cytokine Response to Recombinant Fowlpox Virus but Not the Induction of Plasmacytoid Dendritic Cell-Dependent Adaptive Immunity

2010 ◽  
Vol 84 (13) ◽  
pp. 6549-6563 ◽  
Author(s):  
Erin L. Lousberg ◽  
Cara K. Fraser ◽  
Michael G. Tovey ◽  
Kerrilyn R. Diener ◽  
John D. Hayball
Keyword(s):  
Immune Responses ◽  
Plasmacytoid Dendritic Cell ◽  
Type I Interferons ◽  
Interleukin 12 ◽  
Type I ◽  
Adaptive Immune Responses ◽  
Fowlpox Virus ◽  
Adaptive Immune ◽  
Type I Ifns

ABSTRACT Type I interferons (IFNs) are considered to be important mediators of innate immunity due to their inherent antiviral activity, ability to drive the transcription of a number of genes involved in viral clearance, and their role in the initiation of innate and adaptive immune responses. Due to the central role of type I IFNs, we sought to determine their importance in the generation of immunity to a recombinant vaccine vector fowlpox virus (FPV). In analyzing the role of type I IFNs in immunity to FPV, we show that they are critical to the secretion of a number of innate and proinflammatory cytokines, including type I IFNs themselves as well as interleukin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), IL-6, and IL-1β, and that deficiency leads to enhanced virus-mediated antigen expression. Interestingly, however, type I IFNs were not required for adaptive immune responses to recombinant FPV even though plasmacytoid dendritic cells (pDCs), the primary producers of type I IFNs, have been shown to be requisite for this to occur. Furthermore, we provide evidence that the importance of pDCs may lie in their ability to capture and present virally derived antigen to T cells rather than in their capacity as professional type I IFN-producing cells.

The innate immune system in human systemic lupus erythematosus

2017 ◽  
Vol 131 (8) ◽  
pp. 625-634 ◽  
Author(s):  
Marc Weidenbusch ◽  
Onkar P. Kulkarni ◽  
Hans-Joachim Anders
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Immune System ◽  
Lupus Erythematosus ◽  
Innate Immune System ◽  
Innate Immune ◽  
Type I ◽  
Human Systemic Lupus Erythematosus ◽  
Systemic Lupus ◽  
Adaptive Immune

Although the role of adaptive immune mechanisms, e.g. autoantibody formation and abnormal T-cell activation, has been long noted in the pathogenesis of human systemic lupus erythematosus (SLE), the role of innate immunity has been less well characterized. An intricate interplay between both innate and adaptive immune elements exists in protective anti-infective immunity as well as in detrimental autoimmunity. More recently, it has become clear that the innate immune system in this regard not only starts inflammation cascades in SLE leading to disease flares, but also continues to fuel adaptive immune responses throughout the course of the disease. This is why targeting the innate immune system offers an additional means of treating SLE. First trials assessing the efficacy of anti-type I interferon (IFN) therapy or modulators of pattern recognition receptor (PRR) signalling have been attempted. In this review, we summarize the available evidence on the role of several distinct innate immune elements, especially neutrophils and dendritic cells as well as the IFN system, as well as specific innate PRRs along with their signalling pathways. Finally, we highlight recent clinical trials in SLE addressing one or more of the aforementioned components of the innate immune system.

scholarly journals BIOINFORMATIC SEARCH OF CRISPR/CAS SYSTEM STRUCTURES IN GENOME OF PCT281 PLASMID OF BACILLUS THURINGIENSIS SUBSP. CHINENSIS STRAIN CT-43

2018 ◽  
Vol 3 (5) ◽  
pp. 33-38
Author(s):  
N. A. Arefyeva ◽  
Yu. P. Dzhioev ◽  
A. Yu. Borisenko ◽  
V. I. Chemerilova ◽  
O. F. Vyatchina ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Genome ◽  
Repeat Sequence ◽  
Immune Defense ◽  
System Structure ◽  
Type I ◽  
Adaptive Immune ◽  
Bacillus Thuringiensis Subsp ◽  
New Information

Background.CRISPR/Cas systems loci are one of the functionally important patterns in bacterial genome which perform the role of “adaptive immune defense” from foreign nucleic acids. The study of CRISPR/Cas systems structure in genomes of plasmids and phages provide new information about the evolution of this systems in bacterial hosts.Aims.A search of CRISPR/Cas systems structures in pCT281 plasmid from Bacillus thuringiensis subsp. chinensis strain CT-43 using bioinformatic methods.Materials and methods.Search studies using bioinformatics methods were performed with the genome of pCT281 plasmid of B. thuringiensis subsp. chinensis strain CT-43 from the RefSeq database. To search for the CRISPR/Cas system structure MacSyFinder (ver. 1.0.5) and three combined algorithms were used: CRISPRFinder; PILER-CR; CRISPR Recognition Tool (CRT). The consensus repeat sequence was generated in WebLogo 3.Results and discussion.In pCT281 plasmid we detected one locus of CRISPR/Cas system of the type I-C which contains 2 CRISPR-cassettes and 4 cas-genes located between them. The CRISPR-cassette 1 includes 10 spacers from 32 to 35 bp and 11 repeats 32bp in length. 5 spacers (33–35 bp) separated by 6 repeats 32 bp in length were detected in the CRISPR-cassette 2.Conclusions.The bioinformatic methods used in this study enable to conduct a search of CRISPR/Cas systems structures in plasmid genomes. The presence of the CRISPR-Cas locus in pCT281 plasmid confirms a possible transfer of this system from the nucleoid to this plasmid. The detected spacers provide information about phages this bacteria was encountered.

scholarly journals Characterization of 67 Confirmed Clustered Regularly Interspaced Short Palindromic Repeats Loci in 52 Strains of Staphylococci

2021 ◽  
Vol 12 ◽  
Author(s):  
Ying Wang ◽  
Tingting Mao ◽  
Yinxia Li ◽  
Wenwei Xiao ◽  
Xuan Liang ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Direct Repeat ◽  
Minimum Free Energy ◽  
Important Species ◽  
Crispr Locus ◽  
Adaptive Immune ◽  
Associated Proteins ◽  
The Relationship ◽  
Cas Proteins

Staphylococcus aureus (S. aureus), which is one of the most important species of Staphylococci, poses a great threat to public health. Clustered regularly interspaced short palindromic repeats (CRISPR) and their CRISPR-associated proteins (Cas) are an adaptive immune platform to combat foreign mobile genetic elements (MGEs) such as plasmids and phages. The aim of this study is to describe the distribution and structure of CRISPR-Cas system in S. aureus, and to explore the relationship between CRISPR and horizontal gene transfer (HGT). Here, we analyzed 67 confirmed CRISPR loci and 15 companion Cas proteins in 52 strains of Staphylococci with bioinformatics methods. Comparing with the orphan CRISPR loci in Staphylococci, the strains harboring complete CRISPR-Cas systems contained multiple CRISPR loci, direct repeat sequences (DR) forming stable RNA secondary structures with lower minimum free energy (MFE), and variable spacers with detectable protospacers. In S. aureus, unlike the orphan CRISPRs away from Staphylococcal cassette chromosome mec (SCCmec), the complete CRISPR-Cas systems were in J1 region of SCCmec. In addition, we found a conserved motif 5′-TTCTCGT-3′ that may protect their downstream sequences from DNA interference. In general, orphan CRISPR locus in S. aureus differed greatly from the structural characteristics of the CRISPR-Cas system. Collectively, our results provided new insight into the diversity and characterization of the CRISPR-Cas system in S. aureus.

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