scholarly journals The Bacterium Frischella perrara Causes Scab Formation in the Gut of its Honeybee Host

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Philipp Engel ◽  
Kelsey D. Bartlett ◽  
Nancy A. Moran
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Gut Microbiota ◽  
Bacterial Colonization ◽  
Bacterial Species ◽  
Host Immune System ◽  
Natural Ecosystems ◽  
Epithelial Surface ◽  
Host Interactions ◽  
Key Species

ABSTRACT Honeybees harbor well-defined bacterial communities in their guts. The major members of these communities appear to benefit the host, but little is known about how they interact with the host and specifically how they interface with the host immune system. In the pylorus, a short region between the midgut and hindgut, honeybees frequently exhibit scab-like structures on the epithelial gut surface. These structures are reminiscent of a melanization response of the insect immune system. Despite the wide distribution of this phenotype in honeybee populations, its cause has remained elusive. Here, we show that the presence of a common member of the bee gut microbiota, the gammaproteobacterium Frischella perrara, correlates with the appearance of the scab phenotype. Bacterial colonization precedes scab formation, and F. perrara specifically localizes to the melanized regions of the host epithelium. Under controlled laboratory conditions, we demonstrate that exposure of microbiota-free bees to F. perrara but not to other bacteria results in scab formation. This shows that F. perrara can become established in a spatially restricted niche in the gut and triggers a morphological change of the epithelial surface, potentially due to a host immune response. As an intermittent colonizer, this bacterium holds promise for addressing questions of community invasion in a simple yet relevant model system. Moreover, our results show that gut symbionts of bees engage in differential host interactions that are likely to affect gut homeostasis. Future studies should focus on how these different gut bacteria impact honeybee health. IMPORTANCE As pollinators, honeybees are key species for agricultural and natural ecosystems. Their guts harbor simple communities composed of characteristic bacterial species. Because of these features, bees are ideal systems for studying fundamental aspects of gut microbiota-host interactions. However, little is known about how these bacteria interact with their host. Here, we show that a common member of the bee gut microbiota causes the formation of a scab-like structure on the gut epithelium of its host. This phenotype was first described in 1946, but since then it has not been much further characterized, despite being found in bee populations worldwide. The scab phenotype is reminiscent of melanization, a conserved innate immune response of insects. Our results show that high abundance of one member of the bee gut microbiota triggers this specific phenotype, suggesting that the gut microbiota composition can affect the immune status of this key pollinator species.

Microbiota-Immune System Interactions in Human Neurological Disorders

2020 ◽  
Vol 19 (7) ◽  
pp. 509-526
Author(s):  
Qin Huang ◽  
Fang Yu ◽  
Di Liao ◽  
Jian Xia
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Neurological Disorders ◽  
Brain Function ◽  
Neurological Diseases ◽  
Host Immune System ◽  
Gut Dysbiosis ◽  
Characteristic Features ◽  
Novel Therapeutic Strategies

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.

scholarly journals The Microbiotic Highway to Health—New Perspective on Food Structure, Gut Microbiota, and Host Inflammation

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1590 ◽  
Author(s):  
Nina Hansen ◽  
Anette Sams
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Dietary Habits ◽  
Gut Hormones ◽  
Host Immune System ◽  
Inflammatory Conditions ◽  
Food Structure ◽  
New Perspective ◽  
And Function ◽  
The Impact

This review provides evidence that not only the content of nutrients but indeed the structural organization of nutrients is a major determinant of human health. The gut microbiota provides nutrients for the host by digesting food structures otherwise indigestible by human enzymes, thereby simultaneously harvesting energy and delivering nutrients and metabolites for the nutritional and biological benefit of the host. Microbiota-derived nutrients, metabolites, and antigens promote the development and function of the host immune system both directly by activating cells of the adaptive and innate immune system and indirectly by sustaining release of monosaccharides, stimulating intestinal receptors and secreting gut hormones. Multiple indirect microbiota-dependent biological responses contribute to glucose homeostasis, which prevents hyperglycemia-induced inflammatory conditions. The composition and function of the gut microbiota vary between individuals and whereas dietary habits influence the gut microbiota, the gut microbiota influences both the nutritional and biological homeostasis of the host. A healthy gut microbiota requires the presence of beneficial microbiotic species as well as vital food structures to ensure appropriate feeding of the microbiota. This review focuses on the impact of plant-based food structures, the “fiber-encapsulated nutrient formulation”, and on the direct and indirect mechanisms by which the gut microbiota participate in host immune function.

scholarly journals Mimicry between respiratory virus proteins and some human immune proteins

2020 ◽  
Vol 10 (2) ◽  
pp. 305-314
Author(s):  
I. N. Zhilinskaya
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Amino Acid ◽  
Measles Virus ◽  
Respiratory Infections ◽  
Viral Proteins ◽  
Cellular Protein ◽  
Amino Acid Sequences ◽  
Host Immune System ◽  
Human Immune

A comparative analysis on search for amino acid sequences in viral proteins causing respiratory infections (or respiratory infections syndrome) homologous to amino acid sequences from some human immune proteins was performed. The following viruses were used for comparative computer analysis: coronavirus (SARS-CoV), serotype C subgroup adenovirus C (adenoid 71 strain), measles virus (ICHINOSE-BA strain), rubella (Therien strain) and respiratory syncytial (B1 strain) virus. The search for homologous sequences in viral and human immune proteins was carried out by computer comparison of 12 amino acid fragments, which were assigned as homologous at identity in ≥ 8 positions. The data obtained showed that viral proteins contained homologous motifs in several host immune proteins involved in regulating both the inflammatory response and immune response. Mechanistically, all viruses studied were characterized by sequences homologous to host immune proteins such as complement system proteins, integrins, apoptosis inhibitory proteins, interleukins, and toll-like receptors. Such cellular proteins are actively involved in regulating host inflammatory process and immune response formation. Upon that, a set of host immune proteins, to which homologous fragments were found in viral proteins, was individual for each virus. Interestingly, the largest amount of homologous fragments (up to 20) was mainly concentrated in viral proteins with polymerase and protease activity suggesting that these proteins apart to their major role were involved in production of viral nucleic acids and might participate in regulating host immune system. Envelope, internal and non-structural viral proteins, homologous fragments were detected in much smaller quantities (from 1 to 4). In addition, two fragments homologous to various motifs of the same cellular protein were detected in some viral proteins. Thus, the data obtained further support our understanding that signs of immune system disorders in viral infections can result from multi-layered processes associated with modulation of host innate and adaptive immune system, and open up new approaches to study interaction of viruses with host immune system and identify new functions of viral proteins.

scholarly journals 398 Towards new feeding approaches for optimizing nutritional status, immunity and host-microbiota interactions in neonatal and weaned piglets

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 181-181
Author(s):  
Martin Lessard ◽  
Mylène Blais ◽  
Guylaine Talbot ◽  
J Jacques Matte ◽  
Ann Letellier ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Intestinal Microbiota ◽  
System Development ◽  
Feed Additives ◽  
Epithelial Cell Line ◽  
Host Immune System ◽  
Gut Health ◽  
Weaned Piglets ◽  
Immune System Development

Abstract Lactation, feeding conditions, microbial interventions and piglet growth in the first few weeks of life have important impact on the intestinal microbiota establishment and immune system development of piglets. Indeed, colostrum and milk contain various bioactive components such as immune factors, antimicrobial peptides and oligosaccharides that contribute to maintain intestinal homeostasis and regulate interactions between microbiota and host immune system. Recent results revealed that low birth weight piglet (LBWP) with poor weight gain during the first two weeks of life develop different intestinal microbiota and immune response profiles compared to high BWP (HBWP) littermates. Consequently, piglets within litters may have different resilience to infections after weaning and benefit from feed additives in a specific manner. A study has been performed to evaluate the potential of bovine colostrum extract (BC) as replacement to plasma proteins for improving gut health and resilience to Salmonella infection in piglets. Results revealed that in weaned piglets fed BC, intestinal microbiota was differently modulated and bacterial dysbiosis induced by Salmonella was restored faster. Moreover, expression of genes involved in innate immunity such as β-defensin-2 and glutathione peroxidase-2 was respectively down- and up-regulated in BC fed piglets. A combination of dietary supplementation with BC, cupper and vitamins A and D has also been tested in LBWP and HBWP, and there is clear evidence that BC in combination with other feed additives promote growth and gut health in both LBWP and HBWP. The porcine intestinal epithelial cell line IPEC-J2 was used to better understand the functional properties of BC. Results indicated that BC improves wound healing, enhances barrier function and modulates the expression of several genes involved in innate immune response. Finally, as microbial intervention, the potential of fecal transplantation to modulate intestinal microbiota and immune system development of piglets is under investigation and will be discussed.

scholarly journals Leishmania donovani Secretory Mevalonate Kinase Regulates Host Immune Response and Facilitates Phagocytosis

2021 ◽  
Vol 11 ◽  
Author(s):  
Tanvir Bamra ◽  
Taj Shafi ◽  
Sushmita Das ◽  
Manjay Kumar ◽  
Manas Ranjan Dikhit ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Leishmania Donovani ◽  
Indian Subcontinent ◽  
Parasite Burden ◽  
Host Immune Response ◽  
Host Cells ◽  
Interleukin 4 ◽  
Host Immune System ◽  
Mevalonate Kinase

Summary StatementLeishmania secretes over 151 proteins during in vitro cultivation. Cellular functions of one such novel protein: mevalonate kinase is discussed here; signifying its importance in Leishmania infection.Visceral Leishmaniasis is a persistent infection, caused by Leishmania donovani in Indian subcontinent. This persistence is partly due to phagocytosis and evasion of host immune response. The underlying mechanism involves secretory proteins of Leishmania parasite; however, related studies are meagre. We have identified a novel secretory Leishmania donovani glycoprotein, Mevalonate kinase (MVK), and shown its importance in parasite internalization and immuno-modulation. In our studies, MVK was found to be secreted maximum after 1 h temperature stress at 37°C. Its secretion was increased by 6.5-fold in phagolysosome-like condition (pH ~5.5, 37°C) than at pH ~7.4 and 25°C. Treatment with MVK modulated host immune system by inducing interleukin-10 and interleukin-4 secretion, suppressing host’s ability to kill the parasite. Peripheral blood mononuclear cell (PBMC)-derived macrophages infected with mevalonate kinase-overexpressing parasites showed an increase in intracellular parasite burden in comparison to infection with vector control parasites. Mechanism behind the increase in phagocytosis and immunosuppression was found to be phosphorylation of mitogen-activated protein (MAP) kinase pathway protein, Extracellular signal-regulated kinases-1/2, and actin scaffold protein, cortactin. Thus, we conclude that Leishmania donovani Mevalonate kinase aids in parasite engulfment and subvert the immune system by interfering with signal transduction pathways in host cells, which causes suppression of the protective response and facilitates their persistence in the host. Our work elucidates the involvement of Leishmania in the process of phagocytosis which is thought to be dependent largely on macrophages and contributes towards better understanding of host pathogen interactions.

scholarly journals Sepsis and the Microbiome: A Vicious Cycle

2020 ◽  
Author(s):  
William D Miller ◽  
Robert Keskey ◽  
John C Alverdy
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Gut Microbiota ◽  
Enteral Feeding ◽  
Gut Microbiome ◽  
Antibiotic Stewardship ◽  
Vicious Cycle ◽  
Fecal Transplant ◽  
Suspected Infection

Abstract Although sepsis has been characterized as a dysregulated immune response to an ongoing or suspected infection, the role of the microbiome as a key influencer of the septic response is emerging. The unavoidable disruption of the microbiome while treating sepsis with antibiotics can itself result in immune system dysregulation, further exacerbating the course and outcome of sepsis. Alterations in the gut microbiome as a result of sepsis and its treatment have been implicated in the organ dysfunction typical of sepsis across a wide variety of tissues including the lung, kidney and brain. A number of microbiota directed interventions are currently under investigation in the setting of sepsis including fecal transplant, the administration of dietary fiber in enteral feeding products and the use of antibiotic scavengers that are directed at attenuating the effects of antibiotics on the gut microbiota while allowing them to concentrate at the primary sites of infection. Taken together, the emerging role of the gut microbiome in sepsis touches various elements of the pathophysiology of sepsis and its treatment, and provides yet another reason to consider the judicious use of antibiotics via antibiotic stewardship programs.

scholarly journals Enhancement of immune response against Bordetella spp. by disrupting immunomodulation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Monica C. Gestal ◽  
Laura K. Howard ◽  
Kalyan Dewan ◽  
Hannah M. Johnson ◽  
Mariette Barbier ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Cells ◽  
Lymphoid Tissue ◽  
Protective Immunity ◽  
Inflammatory Cells ◽  
Host Immune System ◽  
Initial Growth ◽  
Wild Type ◽  
Sterilizing Immunity

AbstractWell-adapted pathogens must evade clearance by the host immune system and the study of how they do this has revealed myriad complex strategies and mechanisms. Classical bordetellae are very closely related subspecies that are known to modulate adaptive immunity in a variety of ways, permitting them to either persist for life or repeatedly infect the same host. Exploring the hypothesis that exposure to immune cells would cause bordetellae to induce expression of important immunomodulatory mechanisms, we identified a putative regulator of an immunomodulatory pathway. The deletion of btrS in B. bronchiseptica did not affect colonization or initial growth in the respiratory tract of mice, its natural host, but did increase activation of the inflammasome pathway, and recruitment of inflammatory cells. The mutant lacking btrS recruited many more B and T cells into the lungs, where they rapidly formed highly organized and distinctive Bronchial Associated Lymphoid Tissue (BALT) not induced by any wild type Bordetella species, and a much more rapid and strong antibody response than observed with any of these species. Immunity induced by the mutant was measurably more robust in all respiratory organs, providing completely sterilizing immunity that protected against challenge infections for many months. Moreover, the mutant induced sterilizing immunity against infection with other classical bordetellae, including B. pertussis and B. parapertussis, something the current vaccines do not provide. These findings reveal profound immunomodulation by bordetellae and demonstrate that by disrupting it much more robust protective immunity can be generated, providing a pathway to greatly improve vaccines and preventive treatments against these important pathogens.

scholarly journals Review on the Relationship between Human Polyomaviruses-Associated Tumors and Host Immune System

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Serena Delbue ◽  
Manola Comar ◽  
Pasquale Ferrante
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Human Population ◽  
Host Immune System ◽  
Dna Viruses ◽  
Human Host ◽  
Immunosuppressed Patients ◽  
The Relationship ◽  
Associated Tumors ◽  
Human Polyomaviruses

The polyomaviruses are small DNA viruses that can establish latency in the human host. The name polyomavirus is derived from the Greek rootspoly-, which means “many,” and -oma, which means “tumours.” These viruses were originally isolated in mouse (mPyV) and in monkey (SV40). In 1971, the first human polyomaviruses BK and JC were isolated and subsequently demonstrated to be ubiquitous in the human population. To date, at least nine members of thePolyomaviridaefamily have been identified, some of them playing an etiological role in malignancies in immunosuppressed patients. Here, we describe the biology of human polyomaviruses, their nonmalignant and malignant potentials ability, and their relationship with the host immune response.

scholarly journals A Biofilm Matrix-Associated Protease Inhibitor ProtectsPseudomonas aeruginosafrom Proteolytic Attack

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Boo Shan Tseng ◽  
Courtney Reichhardt ◽  
Gennifer E. Merrihew ◽  
Sophia A. Araujo-Hernandez ◽  
Joe J. Harrison ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Protease Inhibitor ◽  
Neutrophil Elastase ◽  
Matrix Protein ◽  
Lipid Vesicles ◽  
Matrix Proteins ◽  
Host Immune System ◽  
Content Type ◽  
Biofilm Matrix

ABSTRACTPseudomonas aeruginosaproduces an extracellular biofilm matrix that consists of nucleic acids, exopolysaccharides, lipid vesicles, and proteins. In general, the protein component of the biofilm matrix is poorly defined and understudied relative to the other major matrix constituents. While matrix proteins have been suggested to provide many functions to the biofilm, only proteins that play a structural role have been characterized thus far. Here we identify proteins enriched in the matrix ofP. aeruginosabiofilms. We then focused on a candidate matrix protein, the serine protease inhibitor ecotin (PA2755). This protein is able to inhibit neutrophil elastase, a bactericidal enzyme produced by the host immune system duringP. aeruginosabiofilm infections. We show that ecotin binds to the key biofilm matrix exopolysaccharide Psl and that it can inhibit neutrophil elastase when associated with Psl. Finally, we show that ecotin protects both planktonic and biofilmP. aeruginosacells from neutrophil elastase-mediated killing. This may represent a novel mechanism of protection for biofilms to increase their tolerance against the innate immune response.IMPORTANCEProteins associated with the extracellular matrix of bacterial aggregates called biofilms have long been suggested to provide many important functions to the community. To date, however, only proteins that provide structural roles have been described, and few matrix-associated proteins have been identified. We developed a method to identify matrix proteins and characterized one. We show that this protein, when associated with the biofilm matrix, can inhibit a bactericidal enzyme produced by the immune system during infection and protect biofilm cells from death induced by the enzyme. This may represent a novel mechanism of protection for biofilms, further increasing their tolerance against the immune response. Together, our results are the first to show a nonstructural function for a confirmed matrix-interacting protein.

Expression of heat shock proteins 27 and 72 correlates with specific commensal microbes in different regions of porcine gastrointestinal tract

2014 ◽  
Vol 306 (12) ◽  
pp. G1033-G1041 ◽  
Author(s):  
Hao-Yu Liu ◽  
Johan Dicksved ◽  
Torbjörn Lundh ◽  
Jan Erik Lindberg
Keyword(s):  
Immune System ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Bacterial Species ◽  
Host Immune System ◽  
Gi Tract ◽  
Microbe Interactions ◽  
Cell Type Specific ◽  
Host Microbe Interactions ◽  
Shock Proteins

The gastrointestinal (GI) tract of mammals is inhabited by trillions of microorganisms, resulting in exceedingly complex networking. The interaction between distinct bacterial species and the host immune system is essential in maintaining homeostasis in the gut ecosystem. For instance, the gut commensal microbiota dictates intestinal mucosa maturation and its abundant immune components, such as cytoprotective heat shock proteins (HSP). Here we examined physiological expression of HSP in the normal porcine GI tract and found it to be gut region- and cell type-specific in response to dietary components, microbes, and microbial metabolites to which the mucosa surface is exposed. Correlations between HSP72 expression and ileal Lactobacillus spp. and colonic clostridia species, and between HSP27 expression and uronic acid ingestion, were important interplays identified here. Thus this study provides novel insights into host-microbe interactions shaping the immune system that are modifiable by dietary regime.

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