The Role of Hemocytes in the Hawaiian Bobtail Squid, Euprymna scolopes: A Model Organism for Studying Beneficial Host–Microbe Interactions

Host-associated microbial communities have profound impacts on animal physiological function, especially nutrition and metabolism. The hypothesis of ‘symmorphosis’, which posits that the physiological systems of animals are regulated precisely to meet, but not exceed, their imposed functional demands, has been used to understand the integration of physiological systems across levels of biological organization. Although this idea has been criticized, it is recognized as having important heuristic value, even as a null hypothesis, and may, therefore, be a useful tool in understanding how hosts evolve in response to the function of their microbiota. Here, through a hologenomic lens, we discuss how the idea of symmorphosis may be applied to host-microbe interactions. Specifically, we consider scenarios in which host physiology may have evolved to collaborate with the microbiota to perform important functions, and, on the other hand, situations in which services have been completely outsourced to the microbiota, resulting in relaxed selection on host pathways. Following this theoretical discussion, we finally suggest strategies by which these currently speculative ideas may be explicitly tested to further our understanding of host evolution in response to their associated microbial communities. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

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Mucosal microbial parasites/symbionts in health and disease: an integrative overview

Parasitology ◽

10.1017/s0031182019000647 ◽

2019 ◽

Vol 146 (9) ◽

pp. 1109-1115 ◽

Cited By ~ 3

Author(s):

Robert P. Hirt

Keyword(s):

Host Interactions ◽

Detection Techniques ◽

Symbiotic Relationships ◽

Life Styles ◽

Mucosal Surfaces ◽

Microbe Interactions ◽

Health And Disease ◽

Host Microbe Interactions ◽

Species Being

AbstractMicrobial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and intracellular life styles. Their symbiotic relationships can range from commensalism to parasitism and more recently some host–parasites interactions are thought to have evolved into mutualistic associations too. It is increasingly appreciated that this diversity of symbiotic outcomes is the product of a complex network of parasites–microbiota–host interactions. Refinement and broader use of DNA based detection techniques are providing increasing evidence of how common some mucosal microbial parasites are and their host range, with some species being able to swap hosts, including from farm and pet animals to humans. A selection of examples will illustrate the zoonotic potential for a number of microbial parasites and how some species can be either disruptive or beneficial nodes in the complex networks of host–microbe interactions disrupting or maintaining mucosal homoeostasis. It will be argued that mucosal microbial parasitic diversity will represent an important resource to help us dissect through comparative studies the role of host–microbe interactions in both human health and disease.

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The role of the immune system in governing host-microbe interactions in the intestine

Nature Immunology ◽

10.1038/ni.2611 ◽

2013 ◽

Vol 14 (7) ◽

pp. 660-667 ◽

Cited By ~ 191

Author(s):

Eric M Brown ◽

Manish Sadarangani ◽

B Brett Finlay

Keyword(s):

Immune System ◽

Microbe Interactions ◽

Host Microbe Interactions

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Role of Small RNAs in Host-Microbe Interactions

Annual Review of Phytopathology ◽

10.1146/annurev-phyto-073009-114457 ◽

2010 ◽

Vol 48 (1) ◽

pp. 225-246 ◽

Cited By ~ 227

Author(s):

Surekha Katiyar-Agarwal ◽

Hailing Jin

Keyword(s):

Small Rnas ◽

Microbe Interactions ◽

Host Microbe Interactions

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Formicine ants swallow their highly acidic poison for gut microbial selection and control

10.1101/2020.02.13.947432 ◽

2020 ◽

Cited By ~ 1

Author(s):

Simon Tragust ◽

Claudia Herrmann ◽

Jane Häfner ◽

Ronja Braasch ◽

Christina Tilgen ◽

...

Keyword(s):

Social Insects ◽

Dual Role ◽

Poison Gland ◽

Gland Secretion ◽

Acidic Environment ◽

Contaminated Food ◽

Microbe Interactions ◽

Host Microbe Interactions ◽

And Control

AbstractAnimals continuously encounter microorganisms that are essential for health or cause disease. They are thus challenged to control harmful microbes while allowing acquisition of beneficial microbes. This challenge is likely especially important for social insects with respect to microbes in food, as they often store food and exchange food among colony members. Here we show that formicine ants actively swallow their antimicrobial, highly acidic poison gland secretion. The ensuing acidic environment in the stomach, the crop, limits establishment of pathogenic and opportunistic microbes ingested with food and improves survival of ants when faced with pathogen contaminated food. At the same time, crop acidity selectively allows acquisition and colonization by Acetobacteraceae, known bacterial gut associates of formicine ants. This suggests that swallowing of the poison gland secretion acts as a microbial filter in formicine ants and indicates a potentially widespread but so far underappreciated dual role of antimicrobials in host-microbe interactions.

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Glycans in Virus-Host Interactions: A Structural Perspective

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.666756 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nathaniel L. Miller ◽

Thomas Clark ◽

Rahul Raman ◽

Ram Sasisekharan

Keyword(s):

Immune System ◽

Host Cells ◽

Host Immune System ◽

Host Interactions ◽

Viral Glycoproteins ◽

Microbe Interactions ◽

Host Microbe Interactions ◽

Anti Hiv ◽

Structural Perspective

Many interactions between microbes and their hosts are driven or influenced by glycans, whose heterogeneous and difficult to characterize structures have led to an underappreciation of their role in these interactions compared to protein-based interactions. Glycans decorate microbe glycoproteins to enhance attachment and fusion to host cells, provide stability, and evade the host immune system. Yet, the host immune system may also target these glycans as glycoepitopes. In this review, we provide a structural perspective on the role of glycans in host-microbe interactions, focusing primarily on viral glycoproteins and their interactions with host adaptive immunity. In particular, we discuss a class of topological glycoepitopes and their interactions with topological mAbs, using the anti-HIV mAb 2G12 as the archetypical example. We further offer our view that structure-based glycan targeting strategies are ready for application to viruses beyond HIV, and present our perspective on future development in this area.

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CRISPR/Cas9-mediated gene deletion of the ompA gene in symbiotic Enterobacter impairs biofilm formation and reduces gut colonization of Aedes aegypti mosquitoes

10.1101/389957 ◽

2018 ◽

Author(s):

Shivanand Hegde ◽

Pornjarim Nilyanimit ◽

Elena Kozlova ◽

Hema P. Narra ◽

Sanjeev K. Sahni ◽

...

Keyword(s):

Gene Editing ◽

Genetic Factors ◽

Control Strategies ◽

Bacterial Genetics ◽

Site Specific ◽

Gut Colonization ◽

Site Specific Integration ◽

Microbe Interactions ◽

Host Microbe Interactions

AbstractBackgroundSymbiotic bacteria are pervasive in mosquitoes and their presence can influence many host phenotypes that affect vectoral capacity. While it is evident that environmental and host genetic factors contribute in shaping the microbiome of mosquitoes, we have a poor understanding regarding how bacterial genetics affects colonization of the mosquito gut. The CRISPR/Cas9 gene editing system is a powerful tool to alter bacterial genomes facilitating investigations into host-microbe interactions but has yet to be applied to insect symbionts.Methodology/Principal FindingsTo investigate the role of bacterial factors in mosquito biology and in colonization of mosquitoes we used CRISPR/Cas9 gene editing system to mutate the outer membrane protein A (ompA) gene of an Enterobacter symbiont isolated from Aedes mosquitoes. The ompA mutant had an impaired ability to form biofilms and poorly infected Ae. aegypti when reared in a mono-association under gnotobiotic conditions. In adults the mutant had a significantly reduced infection prevalence compared to the wild type or complement strains, while no differences in prevalence were seen in larvae, suggesting bacterial genetic factors are particularly important for adult gut colonization. We also used the CRISPR/Cas9 system to integrate genes (antibiotic resistance and fluorescent markers) into these symbionts genome and demonstrated that these genes were functional in vitro and in vivo.Conclusions/SignificanceOur results shed insights onto the role of ompA gene in host-microbe interactions in Ae. aegypti and confirm that CRISPR/Cas9 gene editing can be employed for genetic manipulation of non-model gut microbes. The ability to use this technology for site-specific integration of genes into the symbiont will facilitate the development of paratransgenic control strategies to interfere with arboviral pathogens such Chikungunya, dengue, Zika and Yellow fever viruses transmitted by Aedes mosquitoes.Author summaryMicrobiota profoundly affect their host but few studies have investigated the role of bacterial genetics in host-microbe interactions in mosquitoes. Here we applied the CRISPR/Cas9 gene editing system to knock out a membrane protein in Enterobacter, which is a dominant member of the mosquito microbiome. The mutant strain lacked the capacity to form biofilms, infected larvae and adults at lower titers, and had a reduced prevalence in adults. The lower prevalence in adults, but not larvae, likely reflects the difference in the modes of bacterial acquisition from the larval water of these two life stages. Importantly from an applied perspective, we also demonstrated that this editing technology can be harnessed for site-specific integration of genes into the bacterial chromosome. In proof-of-principle studies we integrated either a fluorescent protein or gene conferring antibiotic resistance into the bacterial genome and showed these transgenes were functional in mosquitoes. The specificity, flexibility, and simplicity of this editing approach in non-model bacteria will be useful for developing novel symbiotic control strategies to control arthropod-borne disease.

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