Modulation of immune responses to parasitoids by polydnaviruses

Parasitology ◽  
1998 ◽  
Vol 116 (S1) ◽  
pp. S57-S64 ◽  
Author(s):  
N. E. Beckage
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Body Cavity ◽  
The Body ◽  
Parasitoid Wasps ◽  
Host Immune System ◽  
Gene Products ◽  
Successful Development ◽  
Phenoloxidase Activity ◽  
Permanent Cell

SummaryParasitoids are parasites that invariably kill their host. Polydnaviruses are injected by parasitoid wasps into the body cavity of their insect host and cause immunosuppression, allowing the parasitoid to develop in the absence of encapsulation. One of the targets of the polydnaviruses are the haemocytes of the host, which undergo significant changes in response to entry of the virus. In some systems, haemocyte apoptosis is induced, or haemocyte clumping may be seen; in others, the cells round up and fail to adhere to a substrate. Effects on haemocytes may be transitory or permanent (cell death). Various polydnavirus gene products have been identified that interfere with normal haemocyte function. Phenoloxidase activity also is inhibited during parasitism, and the effect is inducible by polydnavirus. In some systems, venom components may act synergistically with polydnavirus in mediating the virally-induced effects on the host immune system. Polydnaviruses are powerful influences on the host immune system, which serve to permit successful development of the parasitoid without triggering the host immune response.

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 Mutual Interplay of Host Immune System and Gut Microbiota in the Immunopathology of Atherosclerosis

2020 ◽  
Vol 21 (22) ◽  
pp. 8729 ◽  
Author(s):  
Chih-Fan Yeh ◽  
Ying-Hsien Chen ◽  
Sheng-Fu Liu ◽  
Hsien-Li Kao ◽  
Ming-Shiang Wu ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Cytokine Production ◽  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Inflammasome Activation ◽  
Host Immune System ◽  
Gut Permeability ◽  
And Function ◽  
Progression Of Atherosclerosis

Inflammation is the key for the initiation and progression of atherosclerosis. Accumulating evidence has revealed that an altered gut microbiome (dysbiosis) triggers both local and systemic inflammation to cause chronic inflammatory diseases, including atherosclerosis. There have been some microbiome-relevant pro-inflammatory mechanisms proposed to link the relationships between dysbiosis and atherosclerosis such as gut permeability disruption, trigger of innate immunity from lipopolysaccharide (LPS), and generation of proatherogenic metabolites, such as trimethylamine N-oxide (TMAO). Meanwhile, immune responses, such as inflammasome activation and cytokine production, could reshape both composition and function of the microbiota. In fact, the immune system delicately modulates the interplay between microbiota and atherogenesis. Recent clinical trials have suggested the potential of immunomodulation as a treatment strategy of atherosclerosis. Here in this review, we present current knowledge regarding to the roles of microbiota in contributing atherosclerotic pathogenesis and highlight translational perspectives by discussing the mutual interplay between microbiota and immune system on atherogenesis.

scholarly journals Role of the microbiome in human development

Gut ◽  
2019 ◽  
Vol 68 (6) ◽  
pp. 1108-1114 ◽  
Author(s):  
Maria Gloria Dominguez-Bello ◽  
Filipa Godoy-Vitorino ◽  
Rob Knight ◽  
Martin J Blaser
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Human Development ◽  
Life Forms ◽  
Host Responses ◽  
Host Immune System ◽  
Next Generation ◽  
Host Health ◽  
Host Development

The host-microbiome supraorganism appears to have coevolved and the unperturbed microbial component of the dyad renders host health sustainable. This coevolution has likely shaped evolving phenotypes in all life forms on this predominantly microbial planet. The microbiota seems to exert effects on the next generation from gestation, via maternal microbiota and immune responses. The microbiota ecosystems develop, restricted to their epithelial niches by the host immune system, concomitantly with the host chronological development, providing early modulation of physiological host development and functions for nutrition, immunity and resistance to pathogens at all ages. Here, we review the role of the microbiome in human development, including evolutionary considerations, and the maternal/fetal relationships, contributions to nutrition and growth. We also discuss what constitutes a healthy microbiota, how antimicrobial modern practices are impacting the human microbiota, the associations between microbiota perturbations, host responses and diseases rocketing in urban societies and potential for future restoration.

scholarly journals Phenoloxidase activity and haemolymph cytology in honeybees challenged with a virus suspension (deformed wings virus DWV) or phosphate buffered suspension (PBS)

2019 ◽  
Vol 49 (2) ◽  
Author(s):  
Francesca Millanta ◽  
Simona Sagona ◽  
Maurizio Mazzei ◽  
Mario Forzan ◽  
Alessandro Poli ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Innate Immune ◽  
Additional Stress ◽  
Varroa Mite ◽  
Virus Suspension ◽  
Phenoloxidase Activity ◽  
Cell Immunity

ABSTRACT: The innate immune system of honeybees mainly consists in antimicrobial peptides, cellular immunity and melanisation. In order to investigate the immune response of honeybees to immune stressors, three stress degrees were tested. Newly emerged bees naturally DWV-infected were collected from a Varroa mite-free apiary and divided into three experimental groups: naturally DWV infected bees, PBS injected bees, and artificially DWV super infected bees. Phenoloxidase activity and haemolymph cellular subtype count were investigated. Phenoloxidase activity was highest (P<0.05) in DWV-superinfected bees, and the haemocyte population differed within the three observed groups. Although, immune responses following DWV infection have still not been completely clarified, this investigation sheds light on the relation between cell immunity and the phenoloxidase activity of DWV-naturally infected honeybees exposed to additional stress such as injury and viral superinfection.

scholarly journals Fungal Extracellular Vesicles as Potential Targets for Immune Interventions

mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Mateus Silveira Freitas ◽  
Vânia Luiza Deperon Bonato ◽  
Andre Moreira Pessoni ◽  
Marcio L. Rodrigues ◽  
Arturo Casadevall ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Nucleic Acids ◽  
Extracellular Vesicles ◽  
Fungal Pathogen ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Therapeutic Strategies ◽  
Host Immune System ◽  
Immunomodulatory Properties

ABSTRACT The release of extracellular vesicles (EVs) by fungi is a fundamental cellular process. EVs carry several biomolecules, including pigments, proteins, enzymes, lipids, nucleic acids, and carbohydrates, and are involved in physiological and pathological processes. EVs may play a pivotal role in the establishment of fungal infections, as they can interact with the host immune system to elicit multiple outcomes. It has been observed that, depending on the fungal pathogen, EVs can exacerbate or attenuate fungal infections. The study of the interaction between fungal EVs and the host immune system and understanding of the mechanisms that regulate those interactions might be useful for the development of new adjuvants as well as the improvement of protective immune responses against infectious or noninfectious diseases. In this review, we describe the immunomodulatory properties of EVs produced by pathogenic fungi and discuss their potential as adjuvants for prophylactic or therapeutic strategies.

Leishmanial selenoproteins and the host immune system: towards new therapeutic strategies?

2020 ◽  
Vol 114 (7) ◽  
pp. 541-544
Author(s):  
Sajad Rashidi ◽  
Kurosh Kalantar ◽  
Paul Nguewa ◽  
Gholamreza Hatam
Keyword(s):  
Immune System ◽  
Adverse Effects ◽  
Immune Responses ◽  
Immune Cells ◽  
Therapeutic Strategies ◽  
Host Immune System ◽  
Host Immune Responses ◽  
Leishmania Parasites

Abstract Optimum levels of selenoproteins are essential for starting and managing the host immune responses against pathogens. According to the expression of selenoproteins in Leishmania parasites, and since high levels of selenoproteins lead to adverse effects on immune cells and their functions, Leishmania parasites might then express selenoproteins such as selenomethionine in their structure and/or secretions able to challenge the host immune system. Finally, this adaptation may lead to evasion of the parasite from the host immune system. The expression of selenoproteins in Leishmania parasites might then induce the development of infection. We therefore suggest these molecules as new therapeutic candidates for the treatment of leishmaniasis.

Immunology Behind Tumors: A Mini Review

2019 ◽  
Vol 15 (3) ◽  
pp. 174-183
Author(s):  
Pooja Hurkat ◽  
Sourabh Jain ◽  
Richa Jain ◽  
Aakanchha Jain
Keyword(s):  
Immune System ◽  
Tumor Microenvironment ◽  
T Lymphocytes ◽  
Immune Responses ◽  
Autoimmune Diseases ◽  
The Body ◽  
Immune Checkpoints ◽  
Genetic Constitution ◽  
Great Care ◽  
B And T Lymphocytes

Background:: The immune system is designed with great care to distinguish self from non-self, as exhibited by immune responses to different pathogens. Furthermore, the immune system has the capacity to distinguish between self from altered self in case of autoimmune diseases like cancer. Developing tumors bypass the immune system mechanism which restrains selfreactive responses. Immunotherapy is a coherent means since the immune system can eliminate a number of antigens derived from the genetic constitution of B and T lymphocytes. Our understanding of the immune system has developed a great deal. Conclusion:: This review is focused not only on the mechanism by which the immune system protects us but also on the ways in which it can inflict the body and how to modulate it with therapy. Thus, understanding the interaction of a tumor with the immune system provides insights into mechanisms that can be utilized to elicit anti-tumor immune responses. Here, we have recapitulated the function of the tumor microenvironment and immune checkpoints.

scholarly journals The immune system as a biomonitor: explorations in innate and adaptive immunity

2013 ◽  
Vol 3 (2) ◽  
pp. 20120099 ◽  
Author(s):  
Niclas Thomas ◽  
James Heather ◽  
Gabriel Pollara ◽  
Nandi Simpson ◽  
Theres Matjeka ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Lymphoid Tissue ◽  
Tissue Injury ◽  
Great Sensitivity ◽  
The Body ◽  
Human Immune System ◽  
Ligand Interactions ◽  
Human Immune ◽  
Body Self

The human immune system has a highly complex, multi-layered structure which has evolved to detect and respond to changes in the internal microenvironment of the body. Recognition occurs at the molecular or submolecular scale, via classical reversible receptor–ligand interactions, and can lead to a response with great sensitivity and speed. Remarkably, recognition is coupled to memory, such that responses are modulated by events which occurred years or even decades before. Although the immune system in general responds differently and more vigorously to stimuli entering the body from the outside (e.g. infections), this is an emergent property of the system: many of the recognition molecules themselves have no inherent bias towards external stimuli (non-self) but also bind targets found within the body (self). It is quite clear that the immune response registers pathophysiological changes in general. Cancer, wounding and chronic tissue injury are some obvious examples. Against this background, the immune system ‘state’ tracks the internal processes of the body, and is likely to encode information regarding both current and past disease processes. Moreover, the distributed nature of most immune responses (e.g. typically involving lymphoid tissue, non-lymphoid tissue, bone marrow, blood, extracellular interstitial spaces, etc.) means that many of the changes associated with immune responses are manifested systemically, and specifically can be detected in blood. This provides a very convenient route to sampling immune cells. We consider two different and complementary ways of querying the human immune ‘state’ using high-dimensional genomic screening methodologies, and discuss the potentials of these approaches and some of the technological and computational challenges to be overcome.

scholarly journals Inflammasome Activation in Bovine Peripheral Blood-Derived Macrophages Is Associated with Actin Rearrangement

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 655
Author(s):  
Amin Tahoun ◽  
Kirsty Jensen ◽  
Hanem El-Sharkawy ◽  
David Gally ◽  
Amira M. Rizk ◽  
...  
Keyword(s):  
Cell Death ◽  
Immune System ◽  
Immune Responses ◽  
Defense Mechanism ◽  
Inflammasome Activation ◽  
Host Immune System ◽  
Bovine Macrophage ◽  
The Relationship ◽  
Actin Localization ◽  
Actin Rearrangement

Inflammation is critical for infection control and acts as an arsenal defense mechanism against invading microbes through activation of the host immune system. It works via its inflammasome components to sense the dangerous invading microorganism and send messages to the immune system to destroy them. To date, the function of bovine macrophage inflammasome and its relationship with actin has not been identified. This study aimed to investigate the activation of bovine inflammasome by phase one flagellin from Salmonella typhimurium and its interaction with actin. Bovine monocyte-derived macrophages were prepared and challenged with S. typhimurium SL1344 phase one flagellin. The results demonstrated the relationship between the flagellin-based activation of inflammasome and actin rearrangement. The flagellin-based activation of inflammasome promoted the activation and co-localization of F-actin and the inflammasome complex. Actin was remodeled to different degrees according to the stage of inflammasome activation. The actin redistribution varied from polymerization to filopodia, while at the stage of pyroptotic cell death, actin was broken down and interacted with activated inflammasome complexes. In conclusion, flagellin-dependent inflammasome activation and actin localization to the inflammasome at the stage of pyroptotic cell death may be of importance for appropriate immune responses, pending further studies to explore the exact cross-linking between the inflammasome complex and actin.

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