Bacterial receptors for host transferrin and lactoferrin: molecular mechanisms and role in host–microbe interactions

2013 ◽  
Vol 8 (12) ◽  
pp. 1575-1585 ◽  
Author(s):  
Ari Morgenthau ◽  
Anastassia Pogoutse ◽  
Paul Adamiak ◽  
Trevor F Moraes ◽  
Anthony B Schryvers
eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Roman M Stilling ◽  
Gerard M Moloney ◽  
Feargal J Ryan ◽  
Alan E Hoban ◽  
Thomaz FS Bastiaanssen ◽  
...  

Social behaviour is regulated by activity of host-associated microbiota across multiple species. However, the molecular mechanisms mediating this relationship remain elusive. We therefore determined the dynamic, stimulus-dependent transcriptional regulation of germ-free (GF) and GF mice colonised post weaning (exGF) in the amygdala, a brain region critically involved in regulating social interaction. In GF mice the dynamic response seen in controls was attenuated and replaced by a marked increase in expression of splicing factors and alternative exon usage in GF mice upon stimulation, which was even more pronounced in exGF mice. In conclusion, we demonstrate a molecular basis for how the host microbiome is crucial for a normal behavioural response during social interaction. Our data further suggest that social behaviour is correlated with the gene-expression response in the amygdala, established during neurodevelopment as a result of host-microbe interactions. Our findings may help toward understanding neurodevelopmental events leading to social behaviour dysregulation, such as those found in autism spectrum disorders (ASDs).


2006 ◽  
Vol 72 (4) ◽  
pp. 2950-2956 ◽  
Author(s):  
Silvia Bulgheresi ◽  
Irma Schabussova ◽  
Tie Chen ◽  
Nicholas P. Mullin ◽  
Rick M. Maizels ◽  
...  

ABSTRACT Although thiotrophic symbioses have been intensively studied for the last three decades, nothing is known about the molecular mechanisms of symbiont acquisition. We used the symbiosis between the marine nematode Laxus oneistus and sulfur-oxidizing bacteria to study this process. In this association a monolayer of symbionts covers the whole cuticle of the nematode, except its anterior-most region. Here, we identify a novel Ca2+-dependent mannose-specific lectin that was exclusively secreted onto the posterior, bacterium-associated region of L. oneistus cuticle. A recombinant form of this lectin induced symbiont aggregation in seawater and was able to compete with the native lectin for symbiont binding in vivo. Surprisingly, the carbohydrate recognition domain of this mannose-binding protein was similar both structurally and functionally to a human dendritic cell-specific immunoreceptor. Our results provide a molecular link between bacterial symbionts and host-secreted mucus in a marine symbiosis and suggest conservation in the mechanisms of host-microbe interactions throughout the animal kingdom.


mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Melissa M. Galey ◽  
Laura M. Sanchez

ABSTRACT Microbial communities contribute to a wide variety of biological functions in hosts and have the ability to specifically influence the health of those organisms through production of specialized metabolites. However, the structures or molecular mechanisms related to health or disease in host-microbe interactions represent a knowledge gap. In order to close this gap, we propose that a combinatory approach, pulling from microbiology and analytical chemistry, be considered to investigate these interactions so as to gain a better understanding of the chemistry being produced. We hypothesize that bacteria alter their chemistry in order to survive and induce specific states in their host organisms. Our lab makes use of imaging mass spectrometry and other analytical techniques to study this chemistry in situ , which provides actionable information to test hypotheses.


2021 ◽  
Vol 25 (2) ◽  
pp. 1-7
Author(s):  
Bok Sil Hong ◽  
Myoung-Ryu Kim

[Purpose] Recent studies have shown that COVID-19 is often associated with altered gut microbiota composition and reflects disease severity. Furthermore, various reports suggest that the interaction between COVID-19 and host-microbiota homeostasis is mediated through the modulation of microRNAs (miRNAs). Thus, in this review, we aim to summarize the association between human microbiota and miRNAs in COVID-19 pathogenesis.[Methods] We searched for the existing literature using the keywords such “COVID-19 or microbiota,” “microbiota or microRNA,” and “COVID-19 or probiotics” in PubMed until March 31, 2021. Subsequently, we thoroughly reviewed the articles related to microbiota and miRNAs in COVID-19 to generate a comprehensive picture depicting the association between human microbiota and microRNAs in the pathogenesis of COVID-19.[Results] There exists strong experimental evidence suggesting that the composition and diversity of human microbiota are altered in COVID-19 patients, implicating a bidirectional association between the respiratory and gastrointestinal tracts. In addition, SARS-CoV-2 encoded miRNAs and host cellular microRNAs modulated by human microbiota can interfere with viral replication and regulate host gene expression involved in the initiation and progression of COVID-19. These findings suggest that the manipulation of human microbiota with probiotics may play a significant role against SARS-CoV-2 infection by enhancing the host immune system and lowering the inflammatory status.[Conclusion] The human microbiota-miRNA axis can be used as a therapeutic approach for COVID-19. Hence, further studies are needed to investigate the exact molecular mechanisms underlying the regulation of miRNA expression in human microbiota and how these miRNA profiles mediate viral infection through host-microbe interactions.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ying Zhao ◽  
Yan Zeng ◽  
Dong Zeng ◽  
Hesong Wang ◽  
Mengjia Zhou ◽  
...  

Probiotics are widely accepted to be beneficial for the maintenance of the gut homeostasis – the dynamic and healthy interactions between host and gut microorganisms. In addition, emerging as a key molecule of inter-domain communication, microRNAs (miRNAs) can also mediate the host–microbe interactions. However, a comprehensive description and summary of the association between miRNAs and probiotics have not been reported yet. In this review, we have discussed the roles of probiotics and miRNAs in host–microbe interactions and proposed the association of probiotics with altered miRNAs in various intestinal diseases and potential molecular mechanisms underlying the action of probiotics. Furthermore, we provided a perspective of probiotics–miRNA–host/gut microbiota axis applied in search of disease management highly associated with the gut microbiome, which will potentially prove to be beneficial for future studies.


2013 ◽  
Vol 109 (S2) ◽  
pp. S27-S34 ◽  
Author(s):  
Miriam Bermudez-Brito ◽  
Julio Plaza-Díaz ◽  
Luis Fontana ◽  
Sergio Muñoz-Quezada ◽  
Angel Gil

Ideally, cell models should resemble the in vivo conditions; however, in most in vitro experimental models, epithelial cells are cultivated as monolayers, in which the establishment of functional epithelial features is not achieved. To overcome this problem, co-culture experiments with probiotics, dendritic cells and intestinal epithelial cells and three-dimensional models attempt to reconcile the complex and dynamic interactions that exist in vivo between the intestinal epithelium and bacteria on the luminal side and between the epithelium and the underlying immune system on the basolateral side. Additional models include tissue explants, bioreactors and organoids. The present review details the in vitro models used to study host–microbe interactions and explores the new tools that may help in understanding the molecular mechanisms of these interactions.


2001 ◽  
Vol 183 (16) ◽  
pp. 4687-4693 ◽  
Author(s):  
Eugenio I. Vivas ◽  
Heidi Goodrich-Blair

ABSTRACT Xenorhabdus nematophilus, a gram-negative bacterium, is a mutualist of Steinernema carpocapsae nematodes and a pathogen of larval-stage insects. We use this organism as a model of host-microbe interactions to identify the functions bacteria require for mutualism, pathogenesis, or both. In many gram-negative bacteria, the transcription factor ςS controls regulons that can mediate stress resistance, survival, or host interactions. Therefore, we examined the role of ςS in the ability of X. nematophilus to interact with its hosts. We cloned, sequenced, and disrupted the X. nematophilus rpoS gene that encodes ςS. The X. nematophilus rpoS mutant pathogenized insects as well as its wild-type parent. However, therpoS mutant could not mutualistically colonize nematode intestines. To our knowledge, this is the first report of a specific allele that affects the ability of X. nematophilus to exist within nematode intestines, an important step in understanding the molecular mechanisms of this association.


2011 ◽  
Vol 55 (4) ◽  
pp. 1494-1503 ◽  
Author(s):  
L. Caetano M. Antunes ◽  
Jun Han ◽  
Rosana B. R. Ferreira ◽  
Petra Lolić ◽  
Christoph H. Borchers ◽  
...  

ABSTRACTThe importance of the mammalian intestinal microbiota to human health has been intensely studied over the past few years. It is now clear that the interactions between human hosts and their associated microbial communities need to be characterized in molecular detail if we are to truly understand human physiology. Additionally, the study of such host-microbe interactions is likely to provide us with new strategies to manipulate these complex systems to maintain or restore homeostasis in order to prevent or cure pathological states. Here, we describe the use of high-throughput metabolomics to shed light on the interactions between the intestinal microbiota and the host. We show that antibiotic treatment disrupts intestinal homeostasis and has a profound impact on the intestinal metabolome, affecting the levels of over 87% of all metabolites detected. Many metabolic pathways that are critical for host physiology were affected, including bile acid, eicosanoid, and steroid hormone synthesis. Dissecting the molecular mechanisms involved in the impact of beneficial microbes on some of these pathways will be instrumental in understanding the interplay between the host and its complex resident microbiota and may aid in the design of new therapeutic strategies that target these interactions.


2019 ◽  
Author(s):  
Lizbeth Sayavedra ◽  
Rebecca Ansorge ◽  
Maxim Rubin-Blum ◽  
Nikolaus Leisch ◽  
Nicole Dubilier ◽  
...  

AbstractDeep-sea bathymodioline mussels gain their nutrition from intracellular bacterial symbionts. Their sulfur-oxidizing (SOX) symbionts were recently shown to encode abundant toxin-related genes (TRGs) in their genomes, which may play a role in beneficial host-microbe interactions. Here, we compared TRGs in the genomes of SOX symbionts from 10 bathymodioline mussel and two sponge species to better understand their potential functions and evolutionary origins. Despite the close phylogenetic relatedness of these symbionts, the number and classes of encoded toxins varied greatly between host species. One of the TRG classes, YDs, has experienced gene expansions multiple times, suggesting that these genes are under adaptive selection. Some symbiont genomes contained secretion systems, which can play a role in host-microbe interactions. Both TRGs and secretion systems had a heterogeneous distribution, suggesting that these closely related bacteria have acquired different molecular mechanisms for interacting with the same family of animal hosts, possibly through convergent evolution.


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