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Frontiers in Immunology 2021
Topics: Animals; Female; Host-Parasite Interactions; Humans; Parasites; Pregnancy; Pregnancy Complications, Parasitic; Protozoan Vaccines
PubMed: 34975925
DOI: 10.3389/fimmu.2021.813446 -
Trends in Parasitology Feb 2020Plasmodium parasites cause malaria and are maintained between Anopheles mosquitoes and mammalian hosts in a complex life cycle. Malaria parasites occupy tissue niches... (Review)
Review
Plasmodium parasites cause malaria and are maintained between Anopheles mosquitoes and mammalian hosts in a complex life cycle. Malaria parasites occupy tissue niches that can be difficult to access, and models to study them can be challenging to recapitulate experimentally, particularly for Plasmodium species that infect humans. 2D culture models provide extremely beneficial tools to investigate Plasmodium biology but they have limitations. More complex 3D structural networks, such as organoids, have unveiled new avenues for developing more physiological tissue models, and their application to malaria research offers great promise. Here, we review current models for studying Plasmodium infection with a key focus on the obligate pre-erythrocytic stage that culminates in blood infection, causing malaria, and discuss how organoids should fulfil an important and unmet need.
Topics: Animals; Host-Parasite Interactions; Humans; Liver; Malaria; Organoids; Parasitology; Plasmodium
PubMed: 31848118
DOI: 10.1016/j.pt.2019.12.003 -
Journal of Helminthology Jan 2023Fish parasitological research associated with fisheries and aquaculture has expanded remarkably over the past century. The application of parasites as biological tags... (Review)
Review
Fish parasitological research associated with fisheries and aquaculture has expanded remarkably over the past century. The application of parasites as biological tags has been one of the fields in which fish parasitology has generated new insight into fish migration and stock assessments worldwide. It is a well-established discipline whose methodological issues are regularly reviewed and updated. Therefore, no concepts or case-studies will be repeated here; instead, we summarize some of the main recent findings and achievements of this methodology. These include the extension of its use in hosts other than bony fishes; the improvements in the selection of parasite tags; the recognition of the host traits affecting the use of parasite tags; and the increasingly recognized need for integrative, multidisciplinary studies combining parasites with classical methods and modern techniques, such as otolith microchemistry and genetics. Archaeological evidence points to the existence of parasitic problems associated with aquaculture activities more than a thousand years ago. However, the main surge of research within aquaculture parasitology occurred with the impressive development of aquaculture over the past century. Protozoan and metazoan parasites, causing disease in domesticated fish in confined environments, have attracted the interest of parasitologists and, due to their economic importance, funding was made available for basic and applied research. This has resulted in a profusion of basic knowledge about parasite biology, physiology, parasite-host interactions, life cycles and biochemistry. Due to the need for effective control methods, various solutions targeting host-parasite interactions (immune responses and host finding), genetics and pharmacological aspects have been in focus.
Topics: Animals; Fisheries; Fish Diseases; Aquaculture; Fishes; Parasites
PubMed: 36631485
DOI: 10.1017/S0022149X22000797 -
MBio Feb 2023Parasite infections affect human and animal health significantly and contribute to a major burden on the global economy. Parasitic protozoan viruses (PPVs) affect the... (Review)
Review
Parasite infections affect human and animal health significantly and contribute to a major burden on the global economy. Parasitic protozoan viruses (PPVs) affect the protozoan parasites' morphology, phenotypes, pathogenicity, and growth rates. This discovery provides an opportunity to develop a novel preventive and therapeutic strategy for parasitic protozoan diseases (PPDs). Currently, there is greater awareness regarding PPVs; however, knowledge of viruses and their associations with host diseases remains limited. Parasite-host interactions become more complex owing to PPVs; however, few studies have investigated underlying viral regulatory mechanisms in parasites. In this study, we reviewed relevant studies to identify studies that investigated PPV development and life cycles, the triangular association between viruses, parasites, and hosts, and the effects of viruses on protozoan pathogenicity. This study highlights that viruses can alter parasite biology, and viral infection of parasites may exacerbate the adverse effects of virus-containing parasites on hosts or reduce parasite virulence. PPVs should be considered in the prevention of parasitic epidemics and outbreaks, although their effects on the host and the complexity of the triangular association between PPVs, protozoans, and hosts remain unclear. PPVs-based regulation of parasitic protozoa can provide a theoretical basis and direction for PPD prevention and control, although PPVs and PPV regulatory mechanisms remain unclear. In this review, we investigated the differences between PPVs and the unique properties of each virus regarding virus discovery, structures, and life cycles, focused on the Trichomonas vaginalis virus, Giardia lamblia virus, RNA virus, and the Cryptosporidium parvum virus 1. The triangular association between PPVs, parasitic protozoa, and hosts reveals the "double-edged sword" property of PPVs, which maintains a balance between parasitic protozoa and hosts in both positive and negative respects. These studies discuss the complexity of parasitic protozoa and their co-existence with hosts and suggest novel pathways for using PPVs as tools to gain a deeper understanding of protozoal infection and treatment.
Topics: Animals; Humans; Parasites; Cryptosporidiosis; Cryptosporidium; Viruses; Protozoan Infections; RNA Viruses
PubMed: 36633419
DOI: 10.1128/mbio.02642-22 -
Trends in Parasitology Jun 2023Anthropogenic stressors are causing fundamental changes in aquatic habitats and to the organisms inhabiting these ecosystems. Yet, we are still far from understanding... (Review)
Review
Anthropogenic stressors are causing fundamental changes in aquatic habitats and to the organisms inhabiting these ecosystems. Yet, we are still far from understanding the diverse responses of parasites and their hosts to these environmental stressors and predicting how these stressors will affect host-parasite communities. Here, we provide an overview of the impacts of major stressors affecting aquatic ecosystems in the Anthropocene (habitat alteration, global warming, and pollution) and highlight their consequences for aquatic parasites at multiple levels of organisation, from the individual to the community level. We provide directions and ideas for future research to better understand responses to stressors in aquatic host-parasite systems.
Topics: Animals; Parasites; Ecosystem; Aquatic Organisms
PubMed: 37061443
DOI: 10.1016/j.pt.2023.03.005 -
Philosophical Transactions of the Royal... Nov 2021Future biodiversity loss threatens the integrity of complex ecological associations, including among hosts and parasites. Almost half of primate species are threatened...
Future biodiversity loss threatens the integrity of complex ecological associations, including among hosts and parasites. Almost half of primate species are threatened with extinction, and the loss of threatened hosts could negatively impact parasite associations and ecosystem functions. If endangered hosts are highly connected in host-parasite networks, then future host extinctions will also drive parasite extinctions, destabilizing ecological networks. If threatened hosts are not highly connected, however, then network structure should not be greatly affected by the loss of threatened hosts. Networks with high connectance, modularity, nestedness and robustness are more resilient to perturbations such as the loss of interactions than sparse, nonmodular and non-nested networks. We analysed the interaction network involving 213 primates and 763 parasites and removed threatened primates (114 species) to simulate the effects of extinction. Our analyses revealed that connections to 23% of primate parasites (176 species) may be lost if threatened primates go extinct. In addition, measures of network structure were affected, but in varying ways because threatened hosts have fewer parasite interactions than non-threatened hosts. These results reveal that host extinctions will perturb the host-parasite network and potentially lead to secondary extinctions of parasites. The ecological consequences of these extinctions remain unclear. This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.
Topics: Animals; Conservation of Natural Resources; Extinction, Biological; Host-Parasite Interactions; Models, Biological; Parasites; Primates
PubMed: 34538137
DOI: 10.1098/rstb.2020.0355 -
Trends in Parasitology Dec 2023A critical part of the malaria parasite's life cycle is invasion of red blood cells (RBCs) by merozoites. Inside RBCs, the parasite forms a schizont, which undergoes... (Review)
Review
A critical part of the malaria parasite's life cycle is invasion of red blood cells (RBCs) by merozoites. Inside RBCs, the parasite forms a schizont, which undergoes segmentation to produce daughter merozoites. These cells are released, establishing cycles of invasion. Traditionally, merozoites are represented as nonmotile, egg-shaped cells that invade RBCs 'narrower end' first and pack within schizonts with this narrower end facing outwards. Here, we discuss recent evidence and re-evaluate previous data which suggest that merozoites are capable of motility and have spherical or elongated-teardrop shapes. Furthermore, merozoites invade RBCs 'wider end' first and pack within schizonts with this wider end facing outwards. We encourage the field to review this revised model and consider its implications for future studies.
Topics: Animals; Parasites; Malaria; Schizonts; Merozoites; Life Cycle Stages
PubMed: 37827961
DOI: 10.1016/j.pt.2023.09.010 -
Frontiers in Cellular and Infection... 2022Malaria parasites are unicellular eukaryotic pathogens that develop through a complex lifecycle involving two hosts, an anopheline mosquito and a vertebrate host.... (Review)
Review
Malaria parasites are unicellular eukaryotic pathogens that develop through a complex lifecycle involving two hosts, an anopheline mosquito and a vertebrate host. Throughout this lifecycle, the parasite encounters widely differing conditions and survives in distinct ways, from an intracellular lifestyle in the vertebrate host to exclusively extracellular stages in the mosquito. Although the parasite relies on cholesterol for its growth, the parasite has an ambiguous relationship with cholesterol: cholesterol is required for invasion of host cells by the parasite, including hepatocytes and erythrocytes, and for the development of the parasites in those cells. However, the parasite is unable to produce cholesterol itself and appears to remove cholesterol actively from its own plasma membrane, thereby setting up a cholesterol gradient inside the infected host erythrocyte. Overall a picture emerges in which the parasite relies on host cholesterol and carefully controls its transport. Here, we describe the role of cholesterol at the different lifecycle stages of the parasites.
Topics: Animals; Cholesterol; Erythrocytes; Life Cycle Stages; Malaria; Parasites; Plasmodium falciparum
PubMed: 36189362
DOI: 10.3389/fcimb.2022.984049 -
European Review For Medical and... Jul 2020Vorinostat is a drug used to treat cutaneous T cell lymphoma whose action mechanism is based on Histone Deacetylase inhibition. Histone Deacetylases are a family of... (Review)
Review
OBJECTIVE
Vorinostat is a drug used to treat cutaneous T cell lymphoma whose action mechanism is based on Histone Deacetylase inhibition. Histone Deacetylases are a family of enzymes that remove acetyl groups from histone and non-histone proteins that control many crucial processes, such as gene regulation, cell cycle progression, differentiation, and apoptosis. Histone Deacetylase homologues are also expressed in parasites of the genus Plasmodium, Leishmania, Cryptosporidium, Schistosoma, Entamoeba, and others. In this way, antiparasitic properties of Vorinostat have been explored. The aim of this review is to report the current state knowledge of Vorinostat as antiparasitic drug against Plasmodium, Leishmania, Cryptosporidium, Schistosoma and Entamoeba in order to support future investigation in this field.
MATERIALS AND METHODS
The authors revised the recent and relevant literature concerning the topic and discussed advances and limitations of studies on Vorinostat as potential drug to treat human parasitic diseases.
RESULTS
Vorinostat has been efficient in vitro and, in some cases, in vivo, against parasites that cause parasitic diseases, such as malaria, leishmaniasis, cryptosporidiosis, amoebiasis, and schistosomiasis.
CONCLUSIONS
In vitro and in vivo models have demonstrated the antiparasitic activity of Vorinostat, however, the challenge is to assay its activity in animal models and to evaluate if Vorinostat is safe for humans as new alternative to treat human parasitic infections.
Topics: Animals; Antiparasitic Agents; Drug Repositioning; Histone Deacetylase Inhibitors; Histone Deacetylases; Host-Parasite Interactions; Humans; Parasites; Parasitic Diseases; Protozoan Proteins; Vorinostat
PubMed: 32706080
DOI: 10.26355/eurrev_202007_21909 -
Expert Opinion on Therapeutic Targets Nov 2019: The proteasome is a multi-subunit enzyme complex responsible for the turnover of short-lived, abnormal or damaged proteins in eukaryotic cells. As organisms that... (Review)
Review
: The proteasome is a multi-subunit enzyme complex responsible for the turnover of short-lived, abnormal or damaged proteins in eukaryotic cells. As organisms that undergo rapid growth and cell division, protozoan parasites exist on the knife-edge of proteotoxic catastrophe and thus rely heavily on their protein quality control machinery for survival. Because of this, the proteasome has recently emerged as a desirable drug target.: This review focuses on efforts to identify protozoan parasite-specific proteasome inhibitors using substrate profiling, library screening, and evolution of resistance approaches to inform medicinal chemistry. Targeting the parasite's 20S proteasome chymotrypsin-like (β5) activity and selectively inhibiting protein turnover in parasites compared to human cells are critical properties of potent, selective inhibitors.: Proteasome inhibitors have the potential for rapid action against all stages, all species and all strains of plasmodium and kinetoplastid parasites. Given the high level of conservation of proteasome active sites in eukaryotes, an important challenge is achieving inhibitors that show sufficient selectivity while maintaining properties consistent with drug development.
Topics: Animals; Antiprotozoal Agents; Drug Development; Humans; Parasites; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Protozoan Infections
PubMed: 31679410
DOI: 10.1080/14728222.2019.1685981