scholarly journals Identification of Biomarkers for Systemic Distribution of Nanovesicles From Lactobacillus johnsonii N6.2

2021 ◽  
Vol 12 ◽  
Author(s):  
Natalie A. Harrison ◽  
Christopher L. Gardner ◽  
Danilo R. da Silva ◽  
Claudio F. Gonzalez ◽  
Graciela L. Lorca
Keyword(s):  
Immune Modulation ◽  
Lactobacillus Johnsonii ◽  
Immunogold Staining ◽  
Intracellular Space ◽  
Host Interactions ◽  
Systemic Distribution ◽  
Significant Enrichment ◽  
Microbe Interactions ◽  
Host Microbe Interactions

The ability of bacterial extracellular vesicles (EV) to transport biological molecules has increased the research to determine their potential as therapeutic agents. In this study, Lactobacillus johnsonii N6.2-derived nanovesicles (NV) were characterized to identify components that may serve as biomarkers in host-microbe interactions. Comparative proteomic and lipidomic analyses of L. johnsonii N6.2 NV and cell membrane (CM) were performed. The lipidomic profiles indicated that both fractions contained similar lipids, however, significant differences were observed in several classes. LC-MS/MS proteomic analysis indicated that NV contained several unique and differentially expressed proteins when compared to the CM. Analysis of Gene Ontology (GO) terms, based on cellular component, showed significant enrichment of proteins in the cytoplasm/intracellular space category for the NV fraction. Based on these results, the proteins T285_RS00825 (named Sdp), Eno3 and LexA were selected for studies of localization and as potential biomarkers for host-microbe interactions. Immunogold staining, followed by scanning and transmission electron microscopy (SEM and TEM, respectively), revealed that Sdp was preferentially localized along the cell wall/membrane, and on NV-like structures surrounding the bacteria. These results were confirmed using immunofluorescence staining in Caco-2 cells incubated with NV. Consequently, we evaluated the potential for NV surface-exposed proteins to generate an immune response in the host. Plasma from individuals administered L. johnsonii N6.2 showed that IgA and IgG antibodies were generated against NV and Sdp domains in vivo. Altogether, these results show that L. johnsonii N6.2 NV have the potential to mediate host interactions through immune modulation.

scholarly journals Organoids to Dissect Gastrointestinal Virus–Host Interactions: What Have We Learned?

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 999
Author(s):  
Sue E. Crawford ◽  
Sasirekha Ramani ◽  
Sarah E. Blutt ◽  
Mary K. Estes
Keyword(s):  
Cell Types ◽  
Human Infection ◽  
Viral Pathogens ◽  
Host Interactions ◽  
Complex Interactions ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Human Intestinal Epithelium ◽  
Human Viruses ◽  
Human Infections

Historically, knowledge of human host–enteric pathogen interactions has been elucidated from studies using cancer cells, animal models, clinical data, and occasionally, controlled human infection models. Although much has been learned from these studies, an understanding of the complex interactions between human viruses and the human intestinal epithelium was initially limited by the lack of nontransformed culture systems, which recapitulate the relevant heterogenous cell types that comprise the intestinal villus epithelium. New investigations using multicellular, physiologically active, organotypic cultures produced from intestinal stem cells isolated from biopsies or surgical specimens provide an exciting new avenue for understanding human specific pathogens and revealing previously unknown host–microbe interactions that affect replication and outcomes of human infections. Here, we summarize recent biologic discoveries using human intestinal organoids and human enteric viral pathogens.

scholarly journals Polymers in the gut compress the colonic mucus hydrogel

2016 ◽  
Vol 113 (26) ◽  
pp. 7041-7046 ◽  
Author(s):  
Sujit S. Datta ◽  
Asher Preska Steinberg ◽  
Rustem F. Ismagilov
Keyword(s):  
Thermodynamic Model ◽  
Ex Vivo ◽  
Polymer Concentration ◽  
Dietary Fibers ◽  
Physical Damage ◽  
Gut Microbes ◽  
Specific Pathogen ◽  
Microbe Interactions ◽  
Host Microbe Interactions

Colonic mucus is a key biological hydrogel that protects the gut from infection and physical damage and mediates host–microbe interactions and drug delivery. However, little is known about how its structure is influenced by materials it comes into contact with regularly. For example, the gut abounds in polymers such as dietary fibers or administered therapeutics, yet whether such polymers interact with the mucus hydrogel, and if so, how, remains unclear. Although several biological processes have been identified as potential regulators of mucus structure, the polymeric composition of the gut environment has been ignored. Here, we demonstrate that gut polymers do in fact regulate mucus hydrogel structure, and that polymer–mucus interactions can be described using a thermodynamic model based on Flory–Huggins solution theory. We found that both dietary and therapeutic polymers dramatically compressed murine colonic mucus ex vivo and in vivo. This behavior depended strongly on both polymer concentration and molecular weight, in agreement with the predictions of our thermodynamic model. Moreover, exposure to polymer-rich luminal fluid from germ-free mice strongly compressed the mucus hydrogel, whereas exposure to luminal fluid from specific-pathogen-free mice—whose microbiota degrade gut polymers—did not; this suggests that gut microbes modulate mucus structure by degrading polymers. These findings highlight the role of mucus as a responsive biomaterial, and reveal a mechanism of mucus restructuring that must be integrated into the design and interpretation of studies involving therapeutic polymers, dietary fibers, and fiber-degrading gut microbes.

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

Parasitology ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. 1109-1115 ◽  
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.

scholarly journals Longitudinal In Vivo Assessment of Host-Microbe Interactions in a Murine Model of Pulmonary Aspergillosis

iScience ◽  
2019 ◽  
Vol 20 ◽  
pp. 184-194 ◽  
Author(s):  
Shweta Saini ◽  
Jennifer Poelmans ◽  
Hannelie Korf ◽  
James L. Dooley ◽  
Sayuan Liang ◽  
...  
Keyword(s):  
Murine Model ◽  
Pulmonary Aspergillosis ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
In Vivo Assessment

scholarly journals A New C-Type Lectin Similar to the Human Immunoreceptor DC-SIGN Mediates Symbiont Acquisition by a Marine Nematode

2006 ◽  
Vol 72 (4) ◽  
pp. 2950-2956 ◽  
Author(s):  
Silvia Bulgheresi ◽  
Irma Schabussova ◽  
Tie Chen ◽  
Nicholas P. Mullin ◽  
Rick M. Maizels ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Marine Nematode ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Marine Symbiosis ◽  
Microbe Interactions ◽  
Sulfur Oxidizing ◽  
Host Microbe Interactions ◽  
Symbiont Acquisition

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.

scholarly journals Identification of Erwinia amylovora Genes Induced during Infection of Immature Pear Tissue

2005 ◽  
Vol 187 (23) ◽  
pp. 8088-8103 ◽  
Author(s):  
Youfu Zhao ◽  
Sara E. Blumer ◽  
George W. Sundin
Keyword(s):  
Pseudomonas Syringae ◽  
Erwinia Amylovora ◽  
Sequence Similarity ◽  
Type Ii Secretion ◽  
Knockout Mutant ◽  
Technology System ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Blight Disease

ABSTRACT The enterobacterium Erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. In this study, we used a modified in vivo expression technology system to identify E. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. We identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes and separated them into nine putative function groups including host-microbe interactions (3.8%), stress response (5.3%), regulation (11.9%), cell surface (8.9%), transport (13.5%), mobile elements (1.0%), metabolism (20.3%), nutrient acquisition and synthesis (15.5%), and unknown or hypothetical proteins (19.8%). Known virulence genes, including hrp/hrc components of the type III secretion system, the major effector gene dspE, type II secretion, levansucrase (lsc), and regulators of levansucrase and amylovoran biosynthesis, were upregulated during pear tissue infection. Known virulence factors previously identified in E. (Pectobacterium) carotovora and Pseudomonas syringae were identified for the first time in E. amylovora and included HecA hemagglutinin family adhesion, Peh polygalacturonase, new effector HopPtoCEA, and membrane-bound lytic murein transglycosylase MltEEA. An insertional mutation within hopPtoC EA did not result in reduced virulence; however, an mltE EA knockout mutant was reduced in virulence and growth in immature pears. This study suggests that E. amylovora utilizes a variety of strategies during plant infection and to overcome the stressful and poor nutritional environment of its plant hosts.

scholarly journals Glycans in Virus-Host Interactions: A Structural Perspective

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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