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•Tsetse PM is constitutively produced by cardia and lines the entire gut.•PM prevents epithelial immune induction against resident microbiota.•PM is a physical barrier trypanosomes ...must bypass for transmission.•Trypanosomes modify tsetse microRNA-275 in cardia to reduce PM synthesis.•Obligate symbiont Wigglesworthia influence PM development in larva.
Tsetse flies are important vectors of parasitic African trypanosomes, agents of human and animal trypanosomiasis. Easily administrable and effective tools for disease control in the mammalian host are still lacking but reduction of the tsetse vector populations can reduce disease. An alternative approach is to reduce the transmission of trypanosomes in the tsetse vector. The gut peritrophic matrix (PM) has emerged as an important regulator of parasite transmission success in tsetse. Tsetse has a Type II PM that is constitutively produced by cells in the cardia organ. Tsetse PM lines the entire gut and functions as an immunological barrier to prevent the gut epithelia from responding to commensal environmental microbes present in the gut lumen. Tsetse PM also functions as a physical barrier to trypanosome infections that enter into the gut lumen in an infective blood meal. For persistence in the gut, African trypanosomes have developed an adaptive manipulative process to transiently reduce PM efficacy. The process is mediated by mammalian trypanosome surface coat proteins, Variant Surface Glycoproteins (VSGs) which are shed in the gut lumen and taken up by cardia cells. The mechanism of PM reduction involves a tsetse microRNA (miR-275) which acts thru the Wnt signaling pathway. The PM efficacy is once again reduced later in the infection process to enable the gut established parasites to reenter into the gut lumen to colonize the salivary glands, an essential process for transmission. The ability to modulate PM integrity can lead to innovative approaches to reduce disease transmission.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Leishmania parasite is transmitted via the bite of a sand fly. In this issue of Cell Host & Microbe, Dey et al. (2018) report that sand fly gut microbiota are also transferred to the bite site, ...promoting neutrophil recruitment and parasite dissemination to distal organs.
The Leishmania parasite is transmitted via the bite of a sand fly. In this issue of Cell Host & Microbe, Dey et al. (2018) report that sand fly gut microbiota are also transferred to the bite site, promoting neutrophil recruitment and parasite dissemination to distal organs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Beneficial microbe functions range from host dietary supplementation to development and maintenance of host immune system. In mammals, newborn progeny are quickly colonized with a symbiotic fauna ...that is provisioned in mother’s milk and that closely resembles that of the parent. Tsetse fly (Diptera: Glossinidae) also depends on the obligate symbiont Wigglesworthia for nutritional supplementation, optimal fecundity, and immune system development. Tsetse progeny develop one at a time in an intrauterine environment and receive nourishment and symbionts in mother’s milk. We show that the host Peptidoglycan Recognition Protein (PGRP-LB) is expressed only in adults and is a major component of the milk that nourishes the developing progeny. The amidase activity associated with PGRP-LB may scavenge the symbiotic peptidoglycan and prevent the induction of tsetse's Immune Deficiency pathway that otherwise can damage the symbionts. Reduction of PGRP-LB experimentally diminishes female fecundity and damages Wigglesworthia in the milk through induction of antimicrobial peptides, including Attacin. Larvae that receive less maternal PGRP-LB give rise to adults with fewer Wigglesworthia and hyperimmune responses. Such adults also suffer dysregulated immunity, as indicated by the presence of higher trypanosome densities in parasitized adults. We show that recPGRP-LB has antimicrobial and antitrypanosomal activities that may regulate symbiosis and impact immunity. Thus, PGRP-LB plays a pivotal role in tsetse’s fitness by protecting symbiosis against host-inflicted damage during development and by controlling parasite infections in adults that can otherwise reduce host fecundity.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Among the 17 diseases classified as NTDs by the World Health Organization are Chagas disease, human African trypanosomiasis, and leishmaniases caused by protozoa; Buruli ulcer, leprosy, trachoma, ...and yaws caused by bacteria; cysticercosis, dracunculiasis, echinococcosis, trematodiases, lynpharic filariasis, onchocerciasis, and schistosomiasis caused by helminthes; and dengue, chikungunya, and rabies caused by viruses 1. Besides their immediate public health concern, NTDs can also be chronic in nature, thriving and promoting poverty among the poorest populations 2. During the next phase, disease-endemic country (DEC) scientists and local health personnel will undoubtedly play the most significant role.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This year PLOS Neglected Tropical Diseases (PLOS NTDs) celebrates its tenth anniversary following the publication of the first issue in 2007 1. When PLOS NTDs was founded, the framework of the ...neglected tropical diseases (NTDs) as an alternative to "other diseases" (as they were then referred to in the Millennium Development Goals) was just getting started-especially for Africa 2, 3. In the decade since, PLOS NTDs has overseen enormous successes in NTD control and elimination. Here, we want to briefly review the ten year progress made towards the control or elimination of the diseases now identified by the WHO as NTDs. Many of the details are highlighted in PLOS NTDs papers cited here, but the summary information is based on the recently released Global Burden of Disease (GBD) Study 2015 (also launched with Gates Foundation support) that summarized past-decade changes in disease prevalence, mortality, or disability rates (from the years 2005 to 2015) 4-6, as well as the GBD Study 2013 that summarizes disease prevalence changes over a longer time horizon from 1990 to 2013 7.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Many insects rely on the presence of symbiotic bacteria for proper immune system function. However, the molecular mechanisms that underlie this phenomenon are poorly understood. Adult tsetse flies ...(Glossina spp.) house three symbiotic bacteria that are vertically transmitted from mother to offspring during this insect's unique viviparous mode of reproduction. Larval tsetse that undergo intrauterine development in the absence of their obligate mutualist, Wigglesworthia, exhibit a compromised immune system during adulthood. In this study, we characterize the immune phenotype of tsetse that develop in the absence of all of their endogenous symbiotic microbes. Aposymbiotic tsetse (Glossina morsitans morsitans Gmm(Apo)) present a severely compromised immune system that is characterized by the absence of phagocytic hemocytes and atypical expression of immunity-related genes. Correspondingly, these flies quickly succumb to infection with normally nonpathogenic Escherichia coli. The susceptible phenotype exhibited by Gmm(Apo) adults can be reversed when they receive hemocytes transplanted from wild-type donor flies prior to infection. Furthermore, the process of immune system development can be restored in intrauterine Gmm(Apo) larvae when their mothers are fed a diet supplemented with Wigglesworthia cell extracts. Our finding that molecular components of Wigglesworthia exhibit immunostimulatory activity within tsetse is representative of a novel evolutionary adaptation that steadfastly links an obligate symbiont with its host.
The importance of tick-borne diseases is increasing all over the world, including Turkey. Global warming, environmental and ecological changes and the existence of suitable habitats increase the ...impact of ticks and result in frequent emergence or re-emergence of tick-borne diseases (TBDs) with zoonotic characteristics. In Turkey, almost 19 TBDs have been reported in animals and men, involving four protozoa (babesiosis, theileriosis, cytauxzoonosis, hepatozoonosis), one filarial nematode (acanthocheilonemasis), ten bacterial agents (anaplasmosis, ehrlichiosis, aegyptianellosis, tick-borne typhus, Candidatus Rickettsia vini, Lyme borreliosis, tick-borne relapsing fever TBRF, tularaemia, bartonellosis, and hemoplasmosis), and four viral infections (tick-borne encephalitis TBE, Crimean-Congo Haemorrhagic Fever CCHF, louping-ill LI, and lumpy skin disease LSD). The growing number of TBD cases, in particular the fatal viral epidemics in humans, have led to increased public awareness and concern against TBDs in recent years. The World Health Organization (WHO) has developed a new political concept, called the "One Health" initiative, which is especially relevant for developing strategies against tick infestations and TBD control in humans and animals. It would be beneficial for Turkey to adopt this new strategy and establish specific research and control programs in coordination with international organizations like WHO, the World Organization for Animal Health (OIE), the Food and Agriculture Organization (FAO), the Centers for Disease Control and Prevention (CDC), and the European Center for Disease Prevention and Control (ECDC) to combat TBDs based on the "One Health Initiative" concept. In this article, we review the occurrence of primary TBDs in man and animals in Turkey in light of the "One Health" perspective.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The World Health Organization (WHO) currently classifies 20 diseases and conditions as neglected tropical diseases (NTDs). However, since its inception in 2007, PLOS Neglected Tropical Diseases has ...considered an expanded list that includes additional diseases with the chronic and/or debilitating, and poverty-promoting features of NTDs. Described here is an update of our current scope, which attempts to embrace all of the NTDs, and a discussion of the status of some of the more debated medical conditions in terms of whether or not they constitute an NTD.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sleeping sickness, also known as human African trypanosomiasis (HAT), is a neglected disease that impacts 70 million people living in 1.55 million km2 in sub-Saharan Africa. Since the beginning of ...the 20th century, there have been multiple HAT epidemics in sub-Saharan Africa, with the most recent epidemic in the 1990s resulting in about half a million HAT cases reported between 1990 and 2015. Here we review the status of HAT disease at the current time and the toolbox available for its control. We also highlight future opportunities under development towards novel or improved interventions.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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