scholarly journals Mitochondria surveillance systems trigger innate immune responses to bacterial pathogens via AMPK pathway in C. elegans

2020 ◽  
Author(s):  
Shouyong Ju ◽  
Hanqiao Chen ◽  
Shaoying Wang ◽  
Jian Lin ◽  
Raffi V Aroian ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune ◽  
Surveillance Systems ◽  
Innate Immune Responses ◽  
Energy Status ◽  
Microbial Infection ◽  
C Elegans ◽  
Host Interaction ◽  
Intracellular Energy

AbstractPathogen recognition and triggering pattern of host innate immune system is critical to understanding pathogen-host interaction. It is generally accepted that the microbial infection can be recognized by host via pattern-triggered immunity (PTI) or effector-triggered immunity (ETI) responses. Recently, non-PRR-mediated cellular surveillance systems have been reported as an important supplement strategy to PTI and ETI responses. However, the mechanism of how surveillance systems sense pathogens and trigger innate immune responses is largely unknown. In the present study, using Bacillus thuringiensis-Caenorhabditis elegans as a model, we found a new approach for surveillance systems to sense the pathogens through no-PPRs patterns. We reported C. elegans can monitor intracellular energy status through the mitochondrial surveillance system to triggered innate immune responses against pathogenic attack via AMP-activated protein kinase (AMPK). Consider that the mitochondria surveillance systems and AMPK are conserved components from worms to mammals, our study suggests that disrupting mitochondrial homeostasis to activate the immune system through AMPK-dependent pathways may widely existing in animals.

scholarly journals C. elegans monitor energy status to trigger innate immune responses via AMPK pathway against bacterial pathogens

2021 ◽  
Author(s):  
Donghai Peng ◽  
Shouyong Ju ◽  
Hanqiao Chen ◽  
Shaoying Wang ◽  
Jian Lin ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Immune Responses ◽  
Surveillance System ◽  
Innate Immune ◽  
Ion Leakage ◽  
Surveillance Systems ◽  
Innate Immune Responses ◽  
Energy Status ◽  
Microbial Infection ◽  
C Elegans

Abstract Pathogen recognition and triggering pattern of host innate immune system is critical to understanding pathogen-host interaction. Cellular surveillance systems have been reported as an important strategy for the identification of microbial infection. In the present study, using Bacillus thuringiensis-Caenorhabditis elegans as a model, we found a new approach for surveillance systems to sense the pathogens. We report that Bacillus thuringiensis produced Cry5Ba, a classical PFTs, leading mitochondrial damage and energy imbalance by causing potassium ion leakage, instead of directly targeting mitochondria. Interestingly, C. elegans can monitor intracellular energy status through the mitochondrial surveillance system to triggered innate immune responses against pathogenic attack via AMP-activated protein kinase (AMPK). Obviously, it is common that pathogens produce toxins to cause potassium leakage. Our study indicate that the imbalance of energy status is a common result of pathogen infection.Besides. AMPK-dependent surveillance system can act as a new stratege for host to recognize and defense pathogens.

scholarly journals The neuropeptide receptor NMUR-1 regulates the specificity of C. elegans innate immunity against pathogen infection

2021 ◽  
Author(s):  
Phillip Wibisono ◽  
Shawndra Wibisono ◽  
Jan Watteyne ◽  
Chia-Hui Chen ◽  
Durai Sellegounder ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Immune Genes ◽  
C Elegans ◽  
Adaptive Immune ◽  
Functional Assays

A key question in current immunology is how the innate immune system generates high levels of specificity. Like most invertebrates, Caenorhabditis elegans does not have an adaptive immune system and relies solely on innate immunity to defend itself against pathogen attacks, yet it can still differentiate different pathogens and launch distinct innate immune responses. Here, we have found that functional loss of NMUR-1, a neuronal GPCR homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans survival against various bacterial pathogens. Transcriptomic analyses and functional assays revealed that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors, which, in turn, controls the expression of distinct immune genes in response to different pathogens. Our study has uncovered a molecular basis for the specificity of C. elegans innate immunity that could provide mechanistic insights into understanding the specificity of vertebrate innate immunity.

scholarly journals STING Requires the Adaptor TRIF to Trigger Innate Immune Responses to Microbial Infection

2016 ◽  
Vol 20 (3) ◽  
pp. 329-341 ◽  
Author(s):  
Xin Wang ◽  
Tanmay Majumdar ◽  
Patricia Kessler ◽  
Evgeny Ozhegov ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Microbial Infection

scholarly journals Commensal and Opportunistic Bacteria Present in the Microbiota in Atlantic Cod (Gadus morhua) Larvae Differentially Alter the Hosts’ Innate Immune Responses

2021 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Ragnhild Inderberg Vestrum ◽  
Torunn Forberg ◽  
Birgit Luef ◽  
Ingrid Bakke ◽  
Per Winge ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Atlantic Cod ◽  
Innate Immune ◽  
Rrna Gene ◽  
Innate Immune Responses ◽  
Transcriptional Responses ◽  
Gut Morphology ◽  
Germ Free ◽  
Opportunistic Bacteria

The roles of host-associated bacteria have gained attention lately, and we now recognise that the microbiota is essential in processes such as digestion, development of the immune system and gut function. In this study, Atlantic cod larvae were reared under germ-free, gnotobiotic and conventional conditions. Water and fish microbiota were characterised by 16S rRNA gene analyses. The cod larvae’s transcriptional responses to the different microbial conditions were analysed by a custom Agilent 44 k oligo microarray. Gut development was assessed by transmission electron microscopy (TEM). Water and fish microbiota differed significantly in the conventional treatment and were dominated by different fast-growing bacteria. Our study indicates that components of the innate immune system of cod larvae are downregulated by the presence of non-pathogenic bacteria, and thus may be turned on by default in the early larval stages. We see indications of decreased nutrient uptake in the absence of bacteria. The bacteria also influence the gut morphology, reflected in shorter microvilli with higher density in the conventional larvae than in the germ-free larvae. The fact that the microbiota alters innate immune responses and gut morphology demonstrates its important role in marine larval development.

scholarly journals Nuclear Hormone Receptor Regulation of MicroRNAs Controls Innate Immune Responses in C. elegans

2013 ◽  
Vol 9 (8) ◽  
pp. e1003545 ◽  
Author(s):  
Feng Liu ◽  
Chen-Xi He ◽  
Li-Jun Luo ◽  
Quan-Li Zou ◽  
Yong-Xu Zhao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Hormone Receptor ◽  
Nuclear Hormone Receptor ◽  
Innate Immune ◽  
Receptor Regulation ◽  
Innate Immune Responses ◽  
C Elegans

The innate immune system

2020 ◽  
pp. 307-314
Author(s):  
Paul Bowness
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Cell Types ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Innate Immune Responses ◽  
Adaptive Immune ◽  
System P ◽  
Different Cell Types

The innate immune system comprises evolutionarily ancient mechanisms that mediate first-line responses against microbial pathogens, and are also important in priming and execution of adaptive immune responses, and in defence against tumours. These responses, which recognize microbial non-self, damaged self, and absent self, are characterized by rapidity of action and they involve various different cell types, cell-associated receptors, and soluble factors. Previously thought to lack plasticity or memory, certain innate immune responses have recently been shown to be capable of ‘learning’ or ‘training’. Most cells of the innate immune system are derived from the myeloid precursors in the bone marrow. These include monocytes and their derivatives—macrophages and dendritic cells, blood granulocytes (neutrophils, basophils, and eosinophils), and tissue mast cells.

scholarly journals PKA/KIN-1 mediates innate immune responses to bacterial pathogens in Caenorhabditis elegans

2017 ◽  
Vol 23 (8) ◽  
pp. 656-666 ◽  
Author(s):  
Yi Xiao ◽  
Fang Liu ◽  
Pei-ji Zhao ◽  
Cheng-Gang Zou ◽  
Ke-Qin Zhang
Keyword(s):  
Innate Immunity ◽  
Nervous System ◽  
Caenorhabditis Elegans ◽  
Immune Responses ◽  
Innate Immune ◽  
Autophagic Flux ◽  
Innate Immune Responses ◽  
C Elegans ◽  
Downstream Effector ◽  
Model Animal

The genetically tractable organism Caenorhabditis elegans is a powerful model animal for the study of host innate immunity. Although the intestine and the epidermis of C. elegans that is in contact with pathogens are likely to function as sites for the immune function, recent studies indicate that the nervous system could control innate immunity in C. elegans. In this report, we demonstrated that protein kinase A (PKA)/KIN-1 in the neurons contributes to resistance against Salmonella enterica infection in C. elegans. Microarray analysis revealed that PKA/KIN-1 regulates the expression of a set of antimicrobial effectors in the non-neuron tissues, which are required for innate immune responses to S. enterica. Furthermore, PKA/KIN-1 regulated the expression of lysosomal genes during S. enterica infection. Our results suggest that the lysosomal signaling molecules are involved in autophagy by controlling autophagic flux, rather than formation of autophagosomes. As autophagy is crucial for host defense against S. enterica infection in a metazoan, the lysosomal pathway also acts as a downstream effector of the PKA/KIN-1 signaling for innate immunity. Our data indicate that the PKA pathway contributes to innate immunity in C. elegans by signaling from the nervous system to periphery tissues to protect the host against pathogens.

scholarly journals STING Requires the Adaptor TRIF to Trigger Innate Immune Responses to Microbial Infection

2017 ◽  
Vol 21 (6) ◽  
pp. 788 ◽  
Author(s):  
Xin Wang ◽  
Tanmay Majumdar ◽  
Patricia Kessler ◽  
Evgeny Ozhegov ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Microbial Infection

scholarly journals Two arms are better than one: parasite variation leads to combined inducible and constitutive innate immune responses

2008 ◽  
Vol 275 (1637) ◽  
pp. 937-945 ◽  
Author(s):  
Ruth Hamilton ◽  
Mike Siva-Jothy ◽  
Mike Boots
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
A Priori ◽  
Innate Immune ◽  
Induced Responses ◽  
Innate Immune Responses ◽  
Defence Mechanisms ◽  
Induced Defences ◽  
Differential Costs ◽  
Better Than

Parasites represent a major threat to all organisms which has led to the evolution of an array of complex and effective defence mechanisms. Common to both vertebrates and invertebrates are innate immune mechanisms that can be either constitutively expressed or induced on exposure to infection. In nature, we find that a combination of both induced and constitutive responses are employed by vertebrates, invertebrates and, to an extent, plants when they are exposed to a parasite. Here we use a simple within-host model motivated by the insect immune system, consisting of both constitutive and induced responses, to address the question of why both types of response are maintained so ubiquitously. Generally, induced responses are thought to be advantageous because they are only used when required but are too costly to maintain constantly, while constitutive responses are advantageous because they are always ready to act. However, using a simple cost function but with no a priori assumptions about relative costs, we show that variability in parasite growth rates selects for a strategy that combines both constitutive and induced defences. Differential costs are therefore not necessary to explain the adoption of both forms of defence. Clearly, hosts are likely to be challenged by variable parasites in nature and this is sufficient to explain why it is optimal to deploy both arms of the innate immune system.

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