scholarly journals Antimicrobial peptides and cell processes tracking endosymbiont dynamics

2016 ◽  
Vol 371 (1695) ◽  
pp. 20150298 ◽  
Author(s):  
Florent Masson ◽  
Anna Zaidman-Rémy ◽  
Abdelaziz Heddi
Keyword(s):  
Immune System ◽  
Antimicrobial Peptides ◽  
Evolutionary Ecology ◽  
Host Cells ◽  
Host Immune System ◽  
Free Living ◽  
Cellular Processes ◽  
Cell Processes ◽  
And Control

Many insects sustain long-term relationships with intracellular symbiotic bacteria that provide them with essential nutrients. Such endosymbiotic relationships likely emerged from ancestral infections of the host by free-living bacteria, the genomes of which experience drastic gene losses and rearrangements during the host–symbiont coevolution. While it is well documented that endosymbiont genome shrinkage results in the loss of bacterial virulence genes, whether and how the host immune system evolves towards the tolerance and control of bacterial partners remains elusive. Remarkably, many insects rely on a ‘compartmentalization strategy’ that consists in secluding endosymbionts within specialized host cells, the bacteriocytes, thus preventing direct symbiont contact with the host systemic immune system. In this review, we compile recent advances in the understanding of the bacteriocyte immune and cellular regulators involved in endosymbiont maintenance and control. We focus on the cereal weevils Sitophilus spp., in which bacteriocytes form bacteriome organs that strikingly evolve in structure and number according to insect development and physiological needs. We discuss how weevils track endosymbiont dynamics through at least two mechanisms: (i) a bacteriome local antimicrobial peptide synthesis that regulates endosymbiont cell cytokinesis and helps to maintain a homeostatic state within bacteriocytes and (ii) some cellular processes such as apoptosis and autophagy which adjust endosymbiont load to the host developmental requirements, hence ensuring a fine-tuned integration of symbiosis costs and benefits. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

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.

An appraisal of survival strategies

Parasitology ◽  
1984 ◽  
Vol 88 (4) ◽  
pp. 575-577 ◽  
Author(s):  
N. A. Mitchison
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Survival Strategies ◽  
Host Immune System ◽  
Cellular Immunology ◽  
Host Immune Responses ◽  
Host Defence System ◽  
Bio Engineering

Only a few years ago parasite immunology looked an unattractive subject better left to the dogged specialists. Parasites and hosts had been playing chess together for a million years, and there seemed little prospect of perturbing matters in favour of the host immune system. All that has changed, for three reasons. Firstly, we have learned how to grow at least some parasites in vitro, and prospects of doing so with others are encouraging. Secondly, progress in cellular immunology has revealed the sort of loopholes in the host defence system which parasites are likely to exploit: we are learning the questions which matter about parasites as antigens. Thirdly, and most importantly, molecular genetics is being brought to bear on parasites: we can now see a real, though long-term, prospect of manufacturing practicable vaccines through bio-engineering, and more immediately it gives us the tools needed to probe the host immune responses in the form of cloned antigens.

scholarly journals Toxoplasma gondii Development of Its Replicative Niche: in Its Host Cell and Beyond

2014 ◽  
Vol 13 (8) ◽  
pp. 965-976 ◽  
Author(s):  
Ira J. Blader ◽  
Anita A. Koshy
Keyword(s):  
Toxoplasma Gondii ◽  
Host Cell ◽  
Host Cells ◽  
Content Type ◽  
Obligate Intracellular ◽  
Cellular Processes ◽  
High Prevalence ◽  
Life Threatening ◽  
Cell Processes ◽  
Cellular Pathways

ABSTRACTIntracellular pathogens can replicate efficiently only after they manipulate and modify their host cells to create an environment conducive to replication. While diverse cellular pathways are targeted by different pathogens, metabolism, membrane and cytoskeletal architecture formation, and cell death are the three primary cellular processes that are modified by infections.Toxoplasma gondiiis an obligate intracellular protozoan that infects ∼30% of the world's population and causes severe and life-threatening disease in developing fetuses, in immune-comprised patients, and in certain otherwise healthy individuals who are primarily found in South America. The high prevalence ofToxoplasmain humans is in large part a result of its ability to modulate these three host cell processes. Here, we highlight recent work defining the mechanisms by whichToxoplasmainteracts with these processes. In addition, we hypothesize why some processes are modified not only in the infected host cell but also in neighboring uninfected cells.

scholarly journals QTL Mapping of Intestinal Neutrophil Variation in Threespine Stickleback Reveals Possible Gene Targets Connecting Intestinal Inflammation and Systemic Health

2019 ◽  
Vol 10 (2) ◽  
pp. 613-622
Author(s):  
Emily A. Beck ◽  
Mark C. Currey ◽  
Clayton M. Small ◽  
William A. Cresko
Keyword(s):  
Immune System ◽  
Inflammatory Response ◽  
Intestinal Inflammation ◽  
Threespine Stickleback ◽  
Microbial Interactions ◽  
Host Cells ◽  
Host Immune System ◽  
Complex Genetics ◽  
Disease States ◽  
Host Genetic

Selection, via host immunity, is often required to foster beneficial microbial symbionts and suppress deleterious pathogens. In animals, the host immune system is at the center of this relationship. Failed host immune system-microbial interactions can result in a persistent inflammatory response in which the immune system indiscriminately attacks resident microbes, and at times the host cells themselves, leading to diseases such as Ulcerative Colitis, Crohn’s Disease, and Psoriasis. Host genetic variation has been linked to both microbiome diversity and to severity of such inflammatory disease states in humans. However, the microbiome and inflammatory states manifest as quantitative traits, which encompass many genes interacting with one another and the environment. The mechanistic relationships among all of these interacting components are still not clear. Developing natural genetic models of host-microbe interactions is therefore fundamental to understanding the complex genetics of these and other diseases. Threespine stickleback (Gasterosteus aculeatus) fish are a tractable model for attacking this problem because of abundant population-level genetic and phenotypic variation in the gut inflammatory response. Previous work in our laboratory identified genetically divergent stickleback populations exhibiting differences in intestinal neutrophil activity. We took advantage of this diversity to genetically map variation in an emblematic element of gut inflammation - intestinal neutrophil recruitment - using an F2-intercross mapping framework. We identified two regions of the genome associated with increased intestinal inflammation containing several promising candidate genes. Within these regions we found candidates in the Coagulation/Complement System, NFkB and MAPK pathways along with several genes associated with intestinal diseases and neurological diseases commonly accompanying intestinal inflammation as a secondary symptom. These findings highlight the utility of using naturally genetically diverse ‘evolutionary mutant models’ such as threespine stickleback to better understand interactions among host genetic diversity and microbiome variation in health and disease states.

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.

scholarly journals Balance and modulation of immunoediting for cancer treatment using synergistic nano-photo-immuno effects

Nanophotonics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3383-3389
Author(s):  
Ashley R. Hoover ◽  
Kaili Liu ◽  
Wei R. Chen
Keyword(s):  
Immune System ◽  
Cancer Treatment ◽  
Tumor Recurrence ◽  
Tumor Metastasis ◽  
Immune Therapy ◽  
Cancer Diagnostics ◽  
Treatment Modalities ◽  
Host Immune System ◽  
Profound Impact

Abstract Nanotechnology, photonics, and immunotherapy are far-reaching technologies with the potential to revolutionize the field of cancer diagnostics and therapeutics. While each technology has limitations in cancer treatment, they can be synergized to exert profound impact on the balance and modulation of immunoediting in tumor microenvironment (TME) and in the entire host immune system. We provide our perspectives on how nano-photo-immuno interactions can be used as an effective therapy, particularly when combined with other treatment modalities, such as checkpoint immune therapy, chemotherapy, and TME modulation, to provide a long-term, tumor-specific immunity against tumor metastasis and tumor recurrence.

scholarly journals A Low-Cost Open Source Device for Cell Microencapsulation

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5090
Author(s):  
Miriam Salles Pereira ◽  
Liana Monteiro da Fonseca Cardoso ◽  
Tatiane Barreto da Silva ◽  
Ayla Josma Teixeira ◽  
Saul Eliahú Mizrahi ◽  
...  
Keyword(s):  
Immune System ◽  
Cell Therapy ◽  
Open Source ◽  
Low Cost ◽  
Cell Encapsulation ◽  
Host Cells ◽  
Host Immune System ◽  
Middle Income ◽  
Encapsulated Cells ◽  
Cell Microencapsulation

Microencapsulation is a widely studied cell therapy and tissue bioengineering technique, since it is capable of creating an immune-privileged site, protecting encapsulated cells from the host immune system. Several polymers have been tested, but sodium alginate is in widespread use for cell encapsulation applications, due to its low toxicity and easy manipulation. Different cell encapsulation methods have been described in the literature using pressure differences or electrostatic changes with high cost commercial devices (about 30,000 US dollars). Herein, a low-cost device (about 100 US dollars) that can be created by commercial syringes or 3D printer devices has been developed. The capsules, whose diameter is around 500 µm and can decrease or increase according to the pressure applied to the system, is able to maintain cells viable and functional. The hydrogel porosity of the capsule indicates that the immune system is not capable of destroying host cells, demonstrating that new studies can be developed for cell therapy at low cost with microencapsulation production. This device may aid pre-clinical and clinical projects in low- and middle-income countries and is lined up with open source equipment devices.

scholarly journals Bases for the Adequate Development of Nutritional Recommendations for Patients with Inflammatory Bowel Disease

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1062 ◽  
Author(s):  
Esteban Sáez-González ◽  
Beatriz Mateos ◽  
Pedro López-Muñoz ◽  
Marisa Iborra ◽  
Inés Moret ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Immune System ◽  
Environmental Factors ◽  
Intestinal Microbiota ◽  
Bowel Disease ◽  
Nutritional Intervention ◽  
Host Cells ◽  
Host Immune System ◽  
Intestinal Immunity ◽  
Inflammatory Bowel

Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory condition of the gastrointestinal tract; it is a heterogeneous and multifactorial disorder resulting from a complex interplay between genetic variation, intestinal microbiota, the host immune system and environmental factors such as diet, drugs, breastfeeding and smoking. The interactions between dietary nutrients and intestinal immunity are complex. There is a compelling argument for environmental factors such as diet playing a role in the cause and course of IBD, given that three important factors in the pathogenesis of IBD can be modulated and controlled by diet: intestinal microbiota, the immune system and epithelial barrier function. The aim of this review is to summarize the epidemiological findings regarding diet and to focus on the effects that nutrients exert on the intestinal mucosa–microbiota–permeability interaction. The nature of these interactions in IBD is influenced by alterations in the nutritional metabolism of the gut microbiota and host cells that can influence the outcome of nutritional intervention. A better understanding of diet–host–microbiota interactions is essential for unravelling the complex molecular basis of epigenetic, genetic and environmental interactions underlying IBD pathogenesis as well as for offering new therapeutic approaches for the treatment of IBD.

COVID-19 Vaccines and Dentistry

Dental Update ◽  
2021 ◽  
Vol 48 (1) ◽  
pp. 76-81
Author(s):  
Lakshman Samaranayake ◽  
Kausar Sadia Fakhruddin
Keyword(s):  
Decision Making ◽  
Immune System ◽  
Antibody Response ◽  
Viral Proteins ◽  
Host Cells ◽  
Bad News ◽  
Host Immune System ◽  
Dental Practice ◽  
The Impact ◽  
Gift Wrapping

Transplant pioneer, Peter Medawar, once said that a virus is ‘simply a piece of bad news wrapped in protein’. One could opine then, that the new COVID-19 vaccines are ‘Bits of corona viral proteins in gift wrapping.’ For, most of the COVID-19 vaccines are based on the principle that pre-exposure of the vaccinee's host immune system to the spike proteins of SARS-CoV-2, the first part of the viral anatomy that touches the vulnerable host cells, will elicit an effective antibody response to curb potential future infections. COVID-19 vaccines come in many sizes and shapes, and clearly, a return to normal, post-COVID dental practice entails protecting all members of the dental team with an appropriate vaccine, as and when available. We provide a thumbnail sketch of the COVID-19 vaccines currently in the offing, which we hope will be helpful for decision-making for choice of vaccine. The commentary ends with a discussion of the impact of COVID-19 vaccines on dentistry, in general.

scholarly journals Antimicrobial defence and persistent infection in insects revisited

2016 ◽  
Vol 371 (1695) ◽  
pp. 20150296 ◽  
Author(s):  
Olga Makarova ◽  
Alex Rodriguez-Rojas ◽  
Murat Eravci ◽  
Chris Weise ◽  
Adam Dobson ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antimicrobial Peptides ◽  
Bacterial Infections ◽  
Time Course ◽  
Evolutionary Ecology ◽  
Cellular Processes ◽  
Gram Positive Bacteria ◽  
Mealworm Beetle

Insects show long-lasting antimicrobial immune responses that follow the initial fast-acting cellular processes. These immune responses are discussed to provide a form of phrophylaxis and/or to serve as a safety measure against persisting infections. The duration and components of such long-lasting responses have rarely been studied in detail, a necessary prerequisite to understand their adaptive value. Here, we present a 21 day proteomic time course of the mealworm beetle Tenebrio molitor immune-challenged with heat-killed Staphylococcus aureus . The most upregulated peptides are antimicrobial peptides (AMPs), many of which are still highly abundant 21 days after infection. The identified AMPs included toll and imd-mediated AMPs, a significant number of which have no known function against S. aureus or other Gram-positive bacteria. The proteome reflects the selective arena for bacterial infections. The results also corroborate the notion of synergistic interactions in vivo that are difficult to model in vitro . This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

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