scholarly journals Bacterial rhamnolipids and their 3-hydroxyalkanoate precursors activate Arabidopsis innate immunity through two independent mechanisms

2021 ◽  
Vol 118 (39) ◽  
pp. e2101366118
Author(s):  
Romain Schellenberger ◽  
Jérôme Crouzet ◽  
Arvin Nickzad ◽  
Lin-Jie Shu ◽  
Alexander Kutschera ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Opportunistic Pathogen ◽  
Receptor Kinase ◽  
Bacterial Surface ◽  
Lectin Receptor ◽  
Invasion Pattern ◽  
Surface Motility ◽  
Biofilm Development ◽  
Successful Colonization

Plant innate immunity is activated upon perception of invasion pattern molecules by plant cell-surface immune receptors. Several bacteria of the genera Pseudomonas and Burkholderia produce rhamnolipids (RLs) from l-rhamnose and (R)-3-hydroxyalkanoate precursors (HAAs). RL and HAA secretion is required to modulate bacterial surface motility, biofilm development, and thus successful colonization of hosts. Here, we show that the lipidic secretome from the opportunistic pathogen Pseudomonas aeruginosa, mainly comprising RLs and HAAs, stimulates Arabidopsis immunity. We demonstrate that HAAs are sensed by the bulb-type lectin receptor kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION/S-DOMAIN-1-29 (LORE/SD1-29), which also mediates medium-chain 3-hydroxy fatty acid (mc-3-OH-FA) perception, in the plant Arabidopsis thaliana. HAA sensing induces canonical immune signaling and local resistance to plant pathogenic Pseudomonas infection. By contrast, RLs trigger an atypical immune response and resistance to Pseudomonas infection independent of LORE. Thus, the glycosyl moieties of RLs, although abolishing sensing by LORE, do not impair their ability to trigger plant defense. Moreover, our results show that the immune response triggered by RLs is affected by the sphingolipid composition of the plasma membrane. In conclusion, RLs and their precursors released by bacteria can both be perceived by plants but through distinct mechanisms.

scholarly journals Rhamnolipids and their 3-(3-hydroxyalkanoyloxy)alkanoic acid precursors activate Arabidopsis innate immunity through two independent mechanisms

2020 ◽  
Author(s):  
Romain Schellenberger ◽  
Jérôme Crouzet ◽  
Arvin Nickzad ◽  
Alexander Kutschera ◽  
Tim Gerster ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Hydroxy Fatty Acid ◽  
Receptor Kinase ◽  
Local Resistance ◽  
Swarming Motility ◽  
Lectin Receptor ◽  
Invasion Pattern ◽  
Bacterial Swarming ◽  
Motility Behavior

AbstractPlant innate immunity is activated upon perception of invasion pattern molecules by plant cell-surface immune receptors. Several bacteria of the genera Pseudomonas and Burkholderia produce rhamnolipids (RLs) from L-rhamnose and (R)-3-hydroxyalkanoate precursors (HAAs). RL and HAA secretion is required to modulate bacterial swarming motility behavior. The bulb-type lectin receptor kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION/S-DOMAIN-1-29 (LORE/SD1-29) mediates medium-chain 3-hydroxy fatty acid (mc-3-OH-FA) sensing in the plant Arabidopsis thaliana. Here, we show that the lipidic secretome from Pseudomonas aeruginosa comprising RLs, HAAs and mc-3-OH-FAs stimulates Arabidopsis immunity. HAAs, like mc-3-O-FAs, are sensed by LORE and induce canonical immune signaling and local resistance to plant pathogenic Pseudomonas infection. By contrast, RLs trigger an atypical immune response and resistance to Pseudomonas infection independent of LORE. Thus, the glycosyl moieties of RLs, albeit abolishing sensing by LORE, do not impair their ability to trigger plant defense. In addition, our results show that RL-triggered immune response is affected by the sphingolipid composition of the plasma membrane. In conclusion, RLs and their precursors released by bacteria can both be perceived by plants but through distinct mechanisms.

CD209 (DC-SIGN) – role in the work of the innate immunity and pathogen penetration

2020 ◽  
Vol 1 (9) ◽  
pp. 64-71
Author(s):  
E. A. Klimov ◽  
◽  
E. K. Novitskaya ◽  
S. N. Koval’chuk ◽  
◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Dendritic Cells ◽  
Inflammatory Response ◽  
Signaling Pathway ◽  
Adhesion Molecule ◽  
Immune Evasion ◽  
Intercellular Adhesion Molecule ◽  
Lectin Receptor

Intercellular adhesion molecule CD209 (DC-SIGN) is a membrane C-type lectin receptor expressed on the surface of dendritic cells and macrophages. CD209 plays an important role in innate immunity. Many studies have shown the possibility of interaction of the CD209 molecule with a number of dangerous pathogens of humans and animals. This review summarizes information on the structure of the CD209 gene and its product, describes the role of the CD209 protein in the immune response, in the migration of dendritic cells from the blood to the tissue, and their interaction with neutrophils. The currently known signaling pathway of activation through the CD209 inflammatory response is presented. The role of CD209 as an endocytic antigen receptor and the participation of the protein in immune evasion of pathogens are discussed. The mechanisms known to date for the development of infections caused by pathogens of various nature in animals are described.

scholarly journals Arabidopsis Lectin Receptor Kinase P2K2 Is a Second Plant Receptor for Extracellular ATP and Contributes to Innate Immunity

2020 ◽  
Vol 183 (3) ◽  
pp. 1364-1375 ◽  
Author(s):  
An Quoc Pham ◽  
Sung-Hwan Cho ◽  
Cuong The Nguyen ◽  
Gary Stacey
Keyword(s):  
Innate Immunity ◽  
Extracellular Atp ◽  
Receptor Kinase ◽  
Lectin Receptor

scholarly journals Surface adhesins and exopolymers of selected foodborne pathogens

Microbiology ◽  
2014 ◽  
Vol 160 (12) ◽  
pp. 2561-2582 ◽  
Author(s):  
Zoran Jaglic ◽  
Mickaël Desvaux ◽  
Agnes Weiss ◽  
Live L. Nesse ◽  
Rikke L. Meyer ◽  
...  
Keyword(s):  
Immune Response ◽  
Foodborne Pathogens ◽  
Bacterial Adhesion ◽  
Clinical Impact ◽  
Surface Structures ◽  
Bacterial Surface ◽  
Abiotic Surfaces ◽  
Specific Manner ◽  
Biofilm Development ◽  
Surface Adhesins

The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalization, avoidance of an immune response, and survival and persistence in the environment. A variety of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm development will also be considered when appropriate. Both the clinical impact and the implications for food safety of such adhesion will be discussed.

scholarly journals Increase in Rhamnolipid Synthesis under Iron-Limiting Conditions Influences Surface Motility and Biofilm Formation in Pseudomonas aeruginosa

2010 ◽  
Vol 192 (12) ◽  
pp. 2973-2980 ◽  
Author(s):  
Rivka Glick ◽  
Christie Gilmour ◽  
Julien Tremblay ◽  
Shirley Satanower ◽  
Ofir Avidan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Essential Element ◽  
Biosurfactant Production ◽  
Twitching Motility ◽  
Wild Type ◽  
Bacterial Surface ◽  
Surface Motility ◽  
Opportunistic Human Pathogen ◽  
Biofilm Development

ABSTRACT Iron is an essential element for life but also serves as an environmental signal for biofilm development in the opportunistic human pathogen Pseudomonas aeruginosa. Under iron-limiting conditions, P. aeruginosa displays enhanced twitching motility and forms flat unstructured biofilms. In this study, we present evidence suggesting that iron-regulated production of the biosurfactant rhamnolipid is important to facilitate the formation of flat unstructured biofilms. We show that under iron limitation the timing of rhamnolipid expression is shifted to the initial stages of biofilm formation (versus later in biofilm development under iron-replete conditions) and results in increased bacterial surface motility. In support of this observation, an rhlAB mutant defective in biosurfactant production showed less surface motility under iron-restricted conditions and developed structured biofilms similar to those developed by the wild type under iron-replete conditions. These results highlight the importance of biosurfactant production in determining the mature structure of P. aeruginosa biofilms under iron-limiting conditions.

scholarly journals Injury-Induced Innate Immune Response During Segment Regeneration of the Earthworm, Eisenia andrei

2021 ◽  
Vol 22 (5) ◽  
pp. 2363
Author(s):  
Kornélia Bodó ◽  
Zoltán Kellermayer ◽  
Zoltán László ◽  
Ákos Boros ◽  
Bohdana Kokhanyuk ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Immune Cell ◽  
Scavenger Receptor ◽  
Cell Renewal ◽  
Body Parts ◽  
Eisenia Andrei ◽  
Blastema Formation ◽  
Close Proximity ◽  
Renewal Period

Regeneration of body parts and their interaction with the immune response is a poorly understood aspect of earthworm biology. Consequently, we aimed to study the mechanisms of innate immunity during regeneration in Eisenia andrei earthworms. In the course of anterior and posterior regeneration, we documented the kinetical aspects of segment restoration by histochemistry. Cell proliferation peaked at two weeks and remitted by four weeks in regenerating earthworms. Apoptotic cells were present throughout the cell renewal period. Distinct immune cell (e.g., coelomocyte) subsets were accumulated in the newly-formed blastema in the close proximity of the apoptotic area. Regenerating earthworms have decreased pattern recognition receptors (PRRs) (e.g., TLR, except for scavenger receptor) and antimicrobial peptides (AMPs) (e.g., lysenin) mRNA patterns compared to intact earthworms. In contrast, at the protein level, mirroring regulation of lysenins became evident. Experimental coelomocyte depletion caused significantly impaired cell divisions and blastema formation during anterior and posterior regeneration. These obtained novel data allow us to gain insight into the intricate interactions of regeneration and invertebrate innate immunity.

scholarly journals Adaptive Evolution of Relish, a Drosophila NF-κB/IκB Protein

Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1231-1238 ◽  
Author(s):  
David J Begun ◽  
Penn Whitley
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Genetic Analysis ◽  
Adaptive Evolution ◽  
Strong Evidence ◽  
Population Genetic ◽  
Microbial Pathogens ◽  
Population Genetic Analysis ◽  
Evolutionary Conflict ◽  
A Site

Abstract NF-κB and IκB proteins have central roles in regulation of inflammation and innate immunity in mammals. Homologues of these proteins also play an important role in regulation of the Drosophila immune response. Here we present a molecular population genetic analysis of Relish, a Drosophila NF-κB/IκB protein, in Drosophila simulans and D. melanogaster. We find strong evidence for adaptive protein evolution in D. simulans, but not in D. melanogaster. The adaptive evolution appears to be restricted to the IκB domain. A possible explanation for these results is that Relish is a site of evolutionary conflict between flies and their microbial pathogens.

scholarly journals Lon Protease Has Multifaceted Biological Functions inAcinetobacter baumannii

2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Carly Ching ◽  
Brendan Yang ◽  
Chineme Onwubueke ◽  
David Lazinski ◽  
Andrew Camilli ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Developmental Process ◽  
Cell Envelope ◽  
Opportunistic Pathogen ◽  
Lon Protease ◽  
Content Type ◽  
Hospital Acquired Infections ◽  
Biofilm Development ◽  
Hospital Acquired

ABSTRACTAcinetobacter baumanniiis a Gram-negative opportunistic pathogen that is known to survive harsh environmental conditions and is a leading cause of hospital-acquired infections. Specifically, multicellular communities (known as biofilms) ofA. baumanniican withstand desiccation and survive on hospital surfaces and equipment. Biofilms are bacteria embedded in a self-produced extracellular matrix composed of proteins, sugars, and/or DNA. Bacteria in a biofilm are protected from environmental stresses, including antibiotics, which provides the bacteria with selective advantage for survival. Although some gene products are known to play roles in this developmental process inA. baumannii, mechanisms and signaling remain mostly unknown. Here, we find that Lon protease inA. baumanniiaffects biofilm development and has other important physiological roles, including motility and the cell envelope. Lon proteases are found in all domains of life, participating in regulatory processes and maintaining cellular homeostasis. These data reveal the importance of Lon protease in influencing keyA. baumanniiprocesses to survive stress and to maintain viability.IMPORTANCEAcinetobacter baumanniiis an opportunistic pathogen and is a leading cause of hospital-acquired infections.A. baumanniiis difficult to eradicate and to manage, because this bacterium is known to robustly survive desiccation and to quickly gain antibiotic resistance. We sought to investigate biofilm formation inA. baumannii, since much remains unknown about biofilm formation in this bacterium. Biofilms, which are multicellular communities of bacteria, are surface attached and difficult to eliminate from hospital equipment and implanted devices. Our research identifies multifaceted physiological roles for the conserved bacterial protease Lon inA. baumannii. These roles include biofilm formation, motility, and viability. This work broadly affects and expands understanding of the biology ofA. baumannii, which will permit us to find effective ways to eliminate the bacterium.

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