Search results for "INTERACTIONS"
showing 10 items of 1963 documents
Gut-microbiota-derived extracellular vesicles: Overlooked mediators in host–helminth interactions?
2021
Helminth infections impact the composition of the mammalian gut microbiota; however, the mechanisms underpinning these interactions are, thus far, unknown. In this article, we propose that microbiota-derived extracellular vesicles might represent key players in host-helminth-microbiome crosstalk, and outline future directions to elucidate their role(s) in host-parasite relationships.
Th2 and Th1 Responses: Clear and Hidden Sides of Immunity Against Intestinal Helminths.
2017
Intestinal helminthiases affect millions of people worldwide, mainly in developing regions, where they cause a significant negative impact on human health and socioeconomic growth of affected populations. However, intestinal helminthiases are still among the most neglected tropical diseases. Protective immunity against intestinal helminths is associated with development of type 2 responses. Nevertheless, in some host–intestinal helminth combinations, local Th1 responses are initiated, inducing chronicity. The usage of helminth–mouse models is useful for elucidating the mechanisms behind the initiation of each type of response. Herein, the current knowledge on these topics is reviewed, payin…
Classic Models for New Perspectives: Delving into Helminth–Microbiota–Immune System Interactions
2018
Whilst a wealth of data indicate that infections by gastrointestinal helminths are accompanied by significant alterations in the composition of the vertebrate gut flora, little is known of the immune-molecular mechanisms that regulate host-parasite-microbiota interactions. 'Traditional' experimental models of gastrointestinal helminthiases, in which the role(s) of each of the components of this triad can be tested, provide an opportunity to advance research in this area. In this article, we propose the Echinostoma caproni-mouse system as a potentially useful tool for studies of the role of the host gut microbiota in preventing pathology and inducing parasite clearance via interleukin (IL)-2…
Hepatitis B Virus Subverts the Autophagy Elongation Complex Atg5-12/16L1 and Does Not Require Atg8/LC3 Lipidation for Viral Maturation
2018
ABSTRACT Previous studies indicated that hepatitis B virus (HBV) stimulates autophagy to favor its production. To understand how HBV co-opts autophagy as a proviral machinery, we studied the roles of key autophagy proteins in HBV-replicating liver cell cultures. RNA interference-mediated silencing of Atg5, Atg12, and Atg16L1, which promote autophagophore expansion and LC3 membrane conjugation, interfered with viral core/nucleocapsid (NC) formation/stability and strongly diminished virus yields. Concomitantly, the core/NC membrane association and their sorting to envelope-positive compartments were perturbed. A close inspection of the HBV/autophagy cross talk revealed that the virus depended…
Rab33B Controls Hepatitis B Virus Assembly by Regulating Core Membrane Association and Nucleocapsid Processing
2017
Many viruses take advantage of cellular trafficking machineries to assemble and release new infectious particles. Using RNA interference (RNAi), we demonstrate that the Golgi/autophagosome-associated Rab33B is required for hepatitis B virus (HBV) propagation in hepatoma cell lines. While Rab33B is dispensable for the secretion of HBV subviral envelope particles, its knockdown reduced the virus yield to 20% and inhibited nucleocapsid (NC) formation and/or NC trafficking. The overexpression of a GDP-restricted Rab33B mutant phenocopied the effect of deficit Rab33B, indicating that Rab33B-specific effector proteins may be involved. Moreover, we found that HBV replication enhanced Rab33B expres…
The immunoglobulin γ marker 17 allotype and KIR/HLA genes prevent the development of chronic hepatitis B in humans
2020
Hepatitis B virus (HBV) infection causes a self-limiting disease in most individuals. However, < 10% of infected subjects develop a chronic disease. Genetic host variability of polymorphic genes at the interface of innate and acquired immunity, such as killer immunoglobulin-like receptors (KIR), their human leucocyte antigen (HLA) and IgG allotypes (GM), could explain this different clinical picture. We previously showed a protective role of the KIR2DL3 gene for the development of chronic hepatitis B (CHB), and a detrimental role of the KIR ligand groups, HLA-A-Bw4 and HLA-C2. We have expanded the previous analysis genotyping patients for GM23 and GM3/17 allotypes. The comparison of the …
Parasitic wasp-associated symbiont affects plant-mediated species interactions between herbivores
2018
Abstract Microbial mutualistic symbiosis is increasingly recognised as a hidden driving force in the ecology of plant–insect interactions. Although plant-associated and herbivore-associated symbionts clearly affect interactions between plants and herbivores, the effects of symbionts associated with higher trophic levels has been largely overlooked. At the third-trophic level, parasitic wasps are a common group of insects that can inject symbiotic viruses (polydnaviruses) and venom into their herbivorous hosts to support parasitoid offspring development. Here, we show that such third-trophic level symbionts act in combination with venom to affect plant-mediated interactions by reducing colon…
Overview of the interaction of helminth extracellular vesicles with the host and their potential functions and biological applications.
2021
Helminth Extracellular Vesicles (EVs) have emerged as important mediators in host-parasite communications, participating in the parasite survival and its pathogenic effects. In the last decade, a growing amount of information reporting the isolation and characterization of EVs from different helminth species has appeared, but unfortunately, few reports have focused on functional studies of helminth EVs in different cell lines, organoids or animal models. We here review these in vitro and in vivo studies, which clearly demonstrate that helminths secrete EVs, which affect their environment. Helminth EVs are actively internalized by different cell lines, modulating cellular functions important…
Role of Immunogenetics in the Outcome of HCMV Infection: Implications for Ageing
2019
The outcome of host-virus interactions is determined by a number of factors, some related to the virus, others to the host, such as environmental factors and genetic factors. Therefore, different individuals vary in their relative susceptibility to infections. Human cytomegalovirus (HCMV) is an important pathogen from a clinical point of view, as it causes significant morbidity and mortality in immunosuppressed or immunosenescent individuals, such as the transplanted patients and the elderly, respectively. It is, therefore, important to understand the mechanisms of virus infection control. In this review, we discuss recent advances in the immunobiology of HCMV-host interactions, with partic…
Regulatory Interaction between the Cellular Restriction Factor IFI16 and Viral pp65 (pUL83) Modulates Viral Gene Expression and IFI16 Protein Stabili…
2016
ABSTRACT A key player in the intrinsic resistance against human cytomegalovirus (HCMV) is the interferon-γ-inducible protein 16 (IFI16), which behaves as a viral DNA sensor in the first hours postinfection and as a repressor of viral gene transcription in the later stages. Previous studies on HCMV replication demonstrated that IFI16 binds to the viral protein kinase pUL97, undergoes phosphorylation, and relocalizes to the cytoplasm of infected cells. In this study, we demonstrate that the tegument protein pp65 (pUL83) recruits IFI16 to the promoter of the UL54 gene and downregulates viral replication, as shown by use of the HCMV mutant v65Stop, which lacks pp65 expression. Interestingly, at…