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Bursali F, Touray M. The complexities of blood-feeding patterns in mosquitoes and sandflies and the burden of disease: A minireview. Vet Med Sci 2024; 10:e1580. [PMID: 39171609 PMCID: PMC11339650 DOI: 10.1002/vms3.1580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 07/26/2024] [Indexed: 08/23/2024] Open
Abstract
Mosquitoes and sandflies exhibit a wide range of blood feeding patterns, targeting a wide range of vertebrate species, including birds, mammals, reptiles, and amphibians, for proteins vital for egg development. This broad host range increases the opportunity for them to acquire pathogens of numerous debilitating-and-fatal diseases from various animal reservoirs, playing a significant role in disease crossover between animals and humans, also known as zoonotic transmission. This review focuses on the intricate blood-feeding habits of these dipteran vectors, their sensory systems and the complex dance between host and pathogen during disease transmission. We delve into the influence of blood sources on pathogen spread by examining the insect immune response and its intricate interplay with pathogens. The remarkable sense of smell guiding them towards food sources and hosts is explored, highlighting the interplay of multiple sensory cues in their navigation. Finally, we examine the challenges in mosquito control strategies and explore innovations in this field, emphasizing the need for sustainable solutions to combat this global health threat. By understanding the biology and behaviour of these insects, we can develop more effective strategies to protect ourselves and mitigate the burden of vector-borne diseases.
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Affiliation(s)
- Fatma Bursali
- Biology Department, Faculty of ScienceAydin Adnan Menderes UniversityAydinTürkiye
| | - Mustapha Touray
- Biology Department, Faculty of ScienceAydin Adnan Menderes UniversityAydinTürkiye
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2
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Araujo S, Mabille D, Garcia AB, Caljon G. A breath of fresh air: impact of insect-borne protozoan parasites on the respiratory system. Trends Parasitol 2024; 40:717-730. [PMID: 39013660 DOI: 10.1016/j.pt.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 07/18/2024]
Abstract
The protozoan parasites Plasmodium, Leishmania, and Trypanosoma are transmitted by hematophagous insects and cause severe diseases in humans. These infections pose a global threat, particularly in low-resource settings, and are increasingly extending beyond the current endemic regions. Tropism of parasites is crucial for their development, and recent studies have revealed colonization of noncanonical tissues, aiding their survival and immune evasion. Despite receiving limited attention, cumulative evidence discloses the respiratory system as a significant interface for host-pathogen interactions, influencing the course of (co)infection and disease onset. Due to its pathophysiological and clinical implications, we emphasize that further research is needed to better understand the involvement of the respiratory system and its potential to improve prevention, diagnosis, treatment, and interruption of the chain of transmission.
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Affiliation(s)
- Sergio Araujo
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Wilrijk, Belgium
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Wilrijk, Belgium
| | - Alvaro Baeza Garcia
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Infla-Med Centre of Excellence, University of Antwerp, Wilrijk, Belgium.
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3
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Jara M, Arevalo J, Llanos-Cuentas A, den Broeck FV, Domagalska MA, Dujardin JC. Unveiling drug-tolerant and persister-like cells in Leishmania braziliensis lines derived from patients with cutaneous leishmaniasis. Front Cell Infect Microbiol 2023; 13:1253033. [PMID: 37790908 PMCID: PMC10543814 DOI: 10.3389/fcimb.2023.1253033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/21/2023] [Indexed: 10/05/2023] Open
Abstract
Introduction Resistance against anti-Leishmania drugs (DR) has been studied for years, giving important insights into long-term adaptations of these parasites to drugs, through genetic modifications. However, microorganisms can also survive lethal drug exposure by entering into temporary quiescence, a phenomenon called drug tolerance (DT), which is rather unexplored in Leishmania. Methods We studied a panel of nine Leishmania braziliensis strains highly susceptible to potassium antimonyl tartrate (PAT), exposed promastigotes to lethal PAT pressure, and compared several cellular and molecular parameters distinguishing DT from DR. Results and discussion We demonstrated in vitro that a variable proportion of cells remained viable, showing all the criteria of DT and not of DR: i) signatures of quiescence, under drug pressure: reduced proliferation and significant decrease of rDNA transcription; ii) reversibility of the phenotype: return to low IC50 after removal of drug pressure; and iii) absence of significant genetic differences between exposed and unexposed lineages of each strain and absence of reported markers of DR. We found different levels of quiescence and DT among the different L. braziliensis strains. We provide here a new in-vitro model of drug-induced quiescence and DT in Leishmania. Research should be extended in vivo, but the current model could be further exploited to support R&D, for instance, to guide the screening of compounds to overcome the quiescence resilience of the parasite, thereby improving the therapy of leishmaniasis.
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Affiliation(s)
- Marlene Jara
- Molecular Parasitology Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - Jorge Arevalo
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Frederik Van den Broeck
- Molecular Parasitology Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Katholieke Universiteit Leuven, Leuven, Belgium
| | | | - Jean-Claude Dujardin
- Molecular Parasitology Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
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4
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García-Estrada C, Pérez-Pertejo Y, Domínguez-Asenjo B, Holanda VN, Murugesan S, Martínez-Valladares M, Balaña-Fouce R, Reguera RM. Further Investigations of Nitroheterocyclic Compounds as Potential Antikinetoplastid Drug Candidates. Biomolecules 2023; 13:biom13040637. [PMID: 37189384 DOI: 10.3390/biom13040637] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Due to the lack of specific vaccines, management of the trypanosomatid-caused neglected tropical diseases (sleeping sickness, Chagas disease and leishmaniasis) relies exclusively on pharmacological treatments. Current drugs against them are scarce, old and exhibit disadvantages, such as adverse effects, parenteral administration, chemical instability and high costs which are often unaffordable for endemic low-income countries. Discoveries of new pharmacological entities for the treatment of these diseases are scarce, since most of the big pharmaceutical companies find this market unattractive. In order to fill the pipeline of compounds and replace existing ones, highly translatable drug screening platforms have been developed in the last two decades. Thousands of molecules have been tested, including nitroheterocyclic compounds, such as benznidazole and nifurtimox, which had already provided potent and effective effects against Chagas disease. More recently, fexinidazole has been added as a new drug against African trypanosomiasis. Despite the success of nitroheterocycles, they had been discarded from drug discovery campaigns due to their mutagenic potential, but now they represent a promising source of inspiration for oral drugs that can replace those currently on the market. The examples provided by the trypanocidal activity of fexinidazole and the promising efficacy of the derivative DNDi-0690 against leishmaniasis seem to open a new window of opportunity for these compounds that were discovered in the 1960s. In this review, we show the current uses of nitroheterocycles and the novel derived molecules that are being synthesized against these neglected diseases.
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Affiliation(s)
- Carlos García-Estrada
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Yolanda Pérez-Pertejo
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Bárbara Domínguez-Asenjo
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Vanderlan Nogueira Holanda
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Sankaranarayanan Murugesan
- Medicinal Chemistry Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science Pilani, Pilani Campus, Pilani 333031, India
| | - María Martínez-Valladares
- Instituto de Ganadería de Montaña (IGM), Consejo Superior de Investigaciones Científicas-Universidad de León, Carretera León-Vega de Infanzones, Vega de Infanzones, 24346 León, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Rosa M. Reguera
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
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5
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Genomic and Phenotypic Characterization of Experimentally Selected Resistant Leishmania donovani Reveals a Role for Dynamin-1-Like Protein in the Mechanism of Resistance to a Novel Antileishmanial Compound. mBio 2022; 13:e0326421. [PMID: 35012338 PMCID: PMC8749414 DOI: 10.1128/mbio.03264-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The implementation of prospective drug resistance (DR) studies in the research-and-development (R&D) pipeline is a common practice for many infectious diseases but not for neglected tropical diseases (NTDs). Here, we explored and demonstrated the importance of this approach using as paradigms Leishmania donovani, the etiological agent of visceral leishmaniasis (VL), and TCMDC-143345, a promising compound of the GlaxoSmithKline (GSK) "Leishbox" to treat VL. We experimentally selected resistance to TCMDC-143345 in vitro and characterized resistant parasites at the genomic and phenotypic levels. We found that it took more time to develop resistance to TCMDC-143345 than to other drugs in clinical use and that there was no cross-resistance to these drugs, suggesting a new and unique mechanism. By whole-genome sequencing, we found two mutations in the gene encoding the L. donovani dynamin-1-like protein (LdoDLP1) that were fixed at the highest drug pressure. Through phylogenetic analysis, we identified LdoDLP1 as a family member of the dynamin-related proteins, a group of proteins that impacts the shapes of biological membranes by mediating fusion and fission events, with a putative role in mitochondrial fission. We found that L. donovani lines genetically engineered to harbor the two identified LdoDLP1 mutations were resistant to TCMDC-143345 and displayed altered mitochondrial properties. By homology modeling, we showed how the two LdoDLP1 mutations may influence protein structure and function. Taken together, our data reveal a clear involvement of LdoDLP1 in the adaptation/reduced susceptibility of L. donovani to TCMDC-143345. IMPORTANCE Humans and their pathogens are continuously locked in a molecular arms race during which the eventual emergence of pathogen drug resistance (DR) seems inevitable. For neglected tropical diseases (NTDs), DR is generally studied retrospectively once it has already been established in clinical settings. We previously recommended to keep one step ahead in the host-pathogen arms race and implement prospective DR studies in the R&D pipeline, a common practice for many infectious diseases but not for NTDs. Here, using Leishmania donovani, the etiological agent of visceral leishmaniasis (VL), and TCMDC-143345, a promising compound of the GSK Leishbox to treat VL, as paradigms, we experimentally selected resistance to the compound and proceeded to genomic and phenotypic characterization of DR parasites. The results gathered in the present study suggest a new DR mechanism involving the L. donovani dynamin-1-like protein (LdoDLP1) and demonstrate the practical relevance of prospective DR studies.
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6
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Borges AR, Link F, Engstler M, Jones NG. The Glycosylphosphatidylinositol Anchor: A Linchpin for Cell Surface Versatility of Trypanosomatids. Front Cell Dev Biol 2021; 9:720536. [PMID: 34790656 PMCID: PMC8591177 DOI: 10.3389/fcell.2021.720536] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/06/2021] [Indexed: 11/20/2022] Open
Abstract
The use of glycosylphosphatidylinositol (GPI) to anchor proteins to the cell surface is widespread among eukaryotes. The GPI-anchor is covalently attached to the C-terminus of a protein and mediates the protein’s attachment to the outer leaflet of the lipid bilayer. GPI-anchored proteins have a wide range of functions, including acting as receptors, transporters, and adhesion molecules. In unicellular eukaryotic parasites, abundantly expressed GPI-anchored proteins are major virulence factors, which support infection and survival within distinct host environments. While, for example, the variant surface glycoprotein (VSG) is the major component of the cell surface of the bloodstream form of African trypanosomes, procyclin is the most abundant protein of the procyclic form which is found in the invertebrate host, the tsetse fly vector. Trypanosoma cruzi, on the other hand, expresses a variety of GPI-anchored molecules on their cell surface, such as mucins, that interact with their hosts. The latter is also true for Leishmania, which use GPI anchors to display, amongst others, lipophosphoglycans on their surface. Clearly, GPI-anchoring is a common feature in trypanosomatids and the fact that it has been maintained throughout eukaryote evolution indicates its adaptive value. Here, we explore and discuss GPI anchors as universal evolutionary building blocks that support the great variety of surface molecules of trypanosomatids.
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Affiliation(s)
- Alyssa R Borges
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Fabian Link
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Markus Engstler
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Nicola G Jones
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
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7
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Khrapunov S, Waterman A, Persaud R, Chang EP. Structure, Function, and Thermodynamics of Lactate Dehydrogenases from Humans and the Malaria Parasite P. falciparum. Biochemistry 2021; 60:3582-3595. [PMID: 34747601 DOI: 10.1021/acs.biochem.1c00470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Temperature adaptation is ubiquitous among all living organisms, yet the molecular basis for this process remains poorly understood. It can be assumed that for parasite-host systems, the same enzymes found in both organisms respond to the same selection factor (human body temperature) with similar structural changes. Herein, we report the existence of a reversible temperature-dependent structural transition for the glycolytic enzyme lactate dehydrogenase (LDH) from the malaria parasite Plasmodium falciparum (pfLDH) and human heart (hhLDH) occurring in the temperature range of human fever. This transition is observed for LDHs from psychrophiles, mesophiles, and moderate thermophiles in their operating temperature range. Thermodynamic analysis reveals unique thermodynamic signatures of the LDH-substrate complexes defining a specific temperature range to which human LDH is adapted and parasite LDH is not, despite their common mesophilic nature. The results of spectroscopic analysis combined with the available crystallographic data reveal the existence of an active center within pfLDH that imparts psychrophilic structural properties to the enzyme. This center consists of two pockets, one formed by the five amino acids (5AA insert) within the substrate specificity loop and the other by the active site, that mutually regulate one another in response to temperature and induce structural and functional changes in the Michaelis complex. Our findings pave the way toward a new strategy for malaria treatments and drug design using therapeutic agents that inactivate malarial LDH selectively at a specific temperature range of the cyclic malaria paroxysm.
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Affiliation(s)
- Sergei Khrapunov
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Akiba Waterman
- Department of Chemistry and Physical Sciences, Pace University, 1 Pace Plaza, New York, New York 10038, United States
| | - Rudra Persaud
- Department of Chemistry and Physical Sciences, Pace University, 1 Pace Plaza, New York, New York 10038, United States
| | - Eric P Chang
- Department of Chemistry and Physical Sciences, Pace University, 1 Pace Plaza, New York, New York 10038, United States
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8
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Pereira LOR, Sousa CS, Ramos HCP, Torres-Santos EC, Pinheiro LS, Alves MR, Cuervo P, Romero GAS, Boité MC, Porrozzi R, Cupolillo E. Insights from Leishmania (Viannia) guyanensis in vitro behavior and intercellular communication. Parasit Vectors 2021; 14:556. [PMID: 34711290 PMCID: PMC8554959 DOI: 10.1186/s13071-021-05057-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pentavalent antimonial-based chemotherapy is the first-line approach for leishmaniasis treatment and disease control. Nevertheless antimony-resistant parasites have been reported in some endemic regions. Treatment refractoriness is complex and is associated with patient- and parasite-related variables. Although amastigotes are the parasite stage in the vertebrate host and, thus, exposed to the drug, the stress caused by trivalent antimony in promastigotes has been shown to promote significant modification in expression of several genes involved in various biological processes, which will ultimately affect parasite behavior. Leishmania (Viannia) guyanensis is one of the main etiological agents in the Amazon Basin region, with a high relapse rate (approximately 25%). METHODS Herein, we conducted several in vitro analyses with L. (V.) guyanensis strains derived from cured and refractory patients after treatment with standardized antimonial therapeutic schemes, in addition to a drug-resistant in vitro-selected strain. Drug sensitivity assessed through Sb(III) half-maximal inhibitory concentration (IC50) assays, growth patterns (with and without drug pressure) and metacyclic-like percentages were determined for all strains and compared to treatment outcomes. Finally, co-cultivation without intercellular contact was followed by parasitic density and Sb(III) IC50 measurements. RESULTS Poor treatment response was correlated with increased Sb(III) IC50 values. The decrease in drug sensitivity was associated with a reduced cell replication rate, increased in vitro growth ability, and higher metacyclic-like proportion. Additionally, in vitro co-cultivation assays demonstrated that intercellular communication enabled lower drug sensitivity and enhanced in vitro growth ability, regardless of direct cell contact. CONCLUSIONS Data concerning drug sensitivity in the Viannia subgenus are emerging, and L. (V.) guyanensis plays a pivotal epidemiological role in Latin America. Therefore, investigating the parasitic features potentially related to relapses is urgent. Altogether, the data presented here indicate that all tested strains of L. (V.) guyanensis displayed an association between treatment outcome and in vitro parameters, especially the drug sensitivity. Remarkably, sharing enhanced growth ability and decreased drug sensitivity, without intercellular communication, were demonstrated.
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Affiliation(s)
- Luiza O R Pereira
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil.
| | - Cíntia S Sousa
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Hellen C P Ramos
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Liliane S Pinheiro
- Laboratório de Bioquímica de Tripanossomatídeos, IOC, FIOCRUZ, Rio de Janeiro, Brazil.,Instituto de Saúde e Biotecnologia, Universidade Federal do Amazonas, Campus Coari, Amazonas, Brazil
| | - Marcelo R Alves
- Laboratório de Pesquisa Clínica em DST-AIDS, Instituto Nacional de Infectologia Evandro Chagas, FIOCRUZ, Rio de Janeiro, Brazil
| | - Patricia Cuervo
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Mariana C Boité
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Renato Porrozzi
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Elisa Cupolillo
- Laboratório de Pesquisa em Leishmanioses, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
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9
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Cecílio P, Pires ACAM, Valenzuela JG, Pimenta PFP, Cordeiro-da-Silva A, Secundino NFC, Oliveira F. Exploring Lutzomyia longipalpis Sand Fly Vector Competence for Leishmania major Parasites. J Infect Dis 2021; 222:1199-1203. [PMID: 32328656 DOI: 10.1093/infdis/jiaa203] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/20/2020] [Indexed: 01/14/2023] Open
Abstract
Lutzomyia longipalpis sand flies are the major natural vector of Leishmania infantum parasites, responsible for transmission of visceral leishmaniasis in the New World. Several experimental studies have demonstrated the ability of Lu. longipalpis to sustain development of different Leishmania species. However, no study had explored in depth the potential vector competence of Lu. longipalpis for Leishmania species other than L. infantum. Here, we show that Lu. longipalpis is a competent vector of L. major parasites, being able to acquire parasites from active cutaneous leishmaniasis lesions, sustain mature infections, and transmit them to naive hosts, causing disease.
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Affiliation(s)
- Pedro Cecílio
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA.,i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Parasite Disease Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Ana Clara A M Pires
- Laboratory of Medical Entomology, Institute René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Brazil.,Graduate Program in Cell Biology, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Jesus G Valenzuela
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Paulo F P Pimenta
- Laboratory of Medical Entomology, Institute René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Brazil.,Graduate Program in Cell Biology, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Institute of Clinical Research Borborema, Tropical Medicine Foundation Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Anabela Cordeiro-da-Silva
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Parasite Disease Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Nagila F C Secundino
- Laboratory of Medical Entomology, Institute René Rachou, Oswaldo Cruz Foundation, Belo Horizonte, Brazil.,Graduate Program in Cell Biology, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Institute of Clinical Research Borborema, Tropical Medicine Foundation Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Fabiano Oliveira
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
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10
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Van Bockstal L, Hendrickx S, Maes L, Caljon G. Sand Fly Studies Predict Transmission Potential of Drug-resistant Leishmania. Trends Parasitol 2020; 36:785-795. [PMID: 32713762 DOI: 10.1016/j.pt.2020.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 01/21/2023]
Abstract
Leishmania parasites have the capacity to rapidly adapt to changing environments in their digenetic life cycle which alternates between a vertebrate and an invertebrate host. Emergence of resistance following drug exposure can evoke phenotypic alterations that affect several aspects of parasite fitness in both hosts. Current studies of the impact of resistance are mostly limited to interactions with the mammalian host and characterization of in vitro parasite growth and differentiation. Development in the vector and transmission capacity have been largely ignored. This review reflects on the impact of drug resistance on its spreading potential with specific focus on the use of the sand fly infection model to evaluate parasite development in the vector and the ensuing transmission potential of drug-resistant phenotypes.
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Affiliation(s)
- Lieselotte Van Bockstal
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Sarah Hendrickx
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
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11
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Manzano-Román R, Fuentes M. Relevance and proteomics challenge of functional posttranslational modifications in Kinetoplastid parasites. J Proteomics 2020; 220:103762. [PMID: 32244008 DOI: 10.1016/j.jprot.2020.103762] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/06/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023]
Abstract
Protozoan parasitic infections are health, social and economic issues impacting both humans and animals, with significant morbidity and mortality worldwide. Protozoan parasites have complicated life cycles with both intracellular and extracellular forms. As a consequence, protozoan adapt to changing environments in part through a dynamic enzyme-catalyzed process leading to reversible posttranslational modifications (PTMs). The characterization by proteomics approaches reveals the critical role of the PTMs of the proteins involved in host-pathogen interaction. The complexity of PTMs characterization is increased by the high diversity, stoichiometry, dynamic and also co-existence of several PTMs in the same moieties which crosstalk between them. Here, we review how to understand the complexity and the essential role of PTMs crosstalk in order to provide a new hallmark for vaccines developments, immunotherapies and personalized medicine. In addition, the importance of these motifs in the biology and biological cycle of kinetoplastid parasites is highlighted with key examples showing the potential to act as targets against protozoan diseases.
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Affiliation(s)
- R Manzano-Román
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain..
| | - M Fuentes
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain.; Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007 Salamanca, Spain; Department of Medicine and General Cytometry Service-Nucleus, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain
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12
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Zininga T, Shonhai A. Small Molecule Inhibitors Targeting the Heat Shock Protein System of Human Obligate Protozoan Parasites. Int J Mol Sci 2019; 20:E5930. [PMID: 31775392 PMCID: PMC6929125 DOI: 10.3390/ijms20235930] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/29/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
Obligate protozoan parasites of the kinetoplastids and apicomplexa infect human cells to complete their life cycles. Some of the members of these groups of parasites develop in at least two systems, the human host and the insect vector. Survival under the varied physiological conditions associated with the human host and in the arthropod vectors requires the parasites to modulate their metabolic complement in order to meet the prevailing conditions. One of the key features of these parasites essential for their survival and host infectivity is timely expression of various proteins. Even more importantly is the need to keep their proteome functional by maintaining its functional capabilities in the wake of physiological changes and host immune responses. For this reason, molecular chaperones (also called heat shock proteins)-whose role is to facilitate proteostasis-play an important role in the survival of these parasites. Heat shock protein 90 (Hsp90) and Hsp70 are prominent molecular chaperones that are generally induced in response to physiological stress. Both Hsp90 and Hsp70 members are functionally regulated by nucleotides. In addition, Hsp70 and Hsp90 cooperate to facilitate folding of some key proteins implicated in cellular development. In addition, Hsp90 and Hsp70 individually interact with other accessory proteins (co-chaperones) that regulate their functions. The dependency of these proteins on nucleotide for their chaperone function presents an Achille's heel, as inhibitors that mimic ATP are amongst potential therapeutic agents targeting their function in obligate intracellular human parasites. Most of the promising small molecule inhibitors of parasitic heat shock proteins are either antibiotics or anticancer agents, whose repurposing against parasitic infections holds prospects. Both cancer cells and obligate human parasites depend upon a robust protein quality control system to ensure their survival, and hence, both employ a competent heat shock machinery to this end. Furthermore, some inhibitors that target chaperone and co-chaperone networks also offer promising prospects as antiparasitic agents. The current review highlights the progress made so far in design and application of small molecule inhibitors against obligate intracellular human parasites of the kinetoplastida and apicomplexan kingdoms.
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Affiliation(s)
| | - Addmore Shonhai
- Department of Biochemistry, School of Mathematical and Natural Sciences, University of Venda, Thohoyandou 0950, South Africa;
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13
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Espinosa A, Paz-Y-Miño-C G. Discrimination Experiments in Entamoeba and Evidence from Other Protists Suggest Pathogenic Amebas Cooperate with Kin to Colonize Hosts and Deter Rivals. J Eukaryot Microbiol 2019; 66:354-368. [PMID: 30055104 PMCID: PMC6349510 DOI: 10.1111/jeu.12673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/27/2018] [Accepted: 07/25/2018] [Indexed: 01/06/2023]
Abstract
Entamoeba histolytica is one of the least understood protists in terms of taxa, clone, and kin discrimination/recognition ability. However, the capacity to tell apart same or self (clone/kin) from different or nonself (nonclone/nonkin) has long been demonstrated in pathogenic eukaryotes like Trypanosoma and Plasmodium, free-living social amebas (Dictyostelium, Polysphondylium), budding yeast (Saccharomyces), and in numerous bacteria and archaea (prokaryotes). Kin discrimination/recognition is explained under inclusive fitness theory; that is, the reproductive advantage that genetically closely related organisms (kin) can gain by cooperating preferably with one another (rather than with distantly related or unrelated individuals), minimizing antagonism and competition with kin, and excluding genetic strangers (or cheaters = noncooperators that benefit from others' investments in altruistic cooperation). In this review, we rely on the outcomes of in vitro pairwise discrimination/recognition encounters between seven Entamoeba lineages to discuss the biological significance of taxa, clone, and kin discrimination/recognition in a range of generalist and specialist species (close or distantly related phylogenetically). We then focus our discussion on the importance of these laboratory observations for E. histolytica's life cycle, host infestation, and implications of these features of the amebas' natural history for human health (including mitigation of amebiasis).
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Affiliation(s)
- Avelina Espinosa
- Department of Biology, Roger Williams University, Bristol, Rhode Island
- New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island
| | - Guillermo Paz-Y-Miño-C
- New England Center for the Public Understanding of Science, Roger Williams University, Bristol, Rhode Island
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14
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Azami M, Ranjkesh Adermanabadi V, Khanahmad H, Mohaghegh MA, Zaherinejad E, Aghaei M, Jalali A, Hejazi SH. Immunology and Genetic of Leishmania infantum: The Role of Endonuclease G in the Apoptosis. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2018; 23:36. [PMID: 29887904 PMCID: PMC5961285 DOI: 10.4103/jrms.jrms_705_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 01/13/2018] [Accepted: 01/31/2018] [Indexed: 12/13/2022]
Abstract
Leishmania infantum is the causative agent of infantile visceral leishmaniasis (VL) in the Mediterranean region. Despite developing protective responses, the disease progresses due to many of factors. These include the action of suppressive cytokines, exhaustion of specific T cells, loss of lymphoid tissue, and defective humoral response. Genetic changes that occur inside the genome of alienated or parasite cells, along with immune responses, play an important role in controlling or progressing the disease. Proapoptotic proteins such as Smac/DIABLO, EndoG, AIF (apoptosis-inducing factor), and cytochrome C are effective in apoptosis. EndoG is a mitochondrion-specific nuclease that translocates to the nucleus during apoptosis. Once released from mitochondria, endoG cleaves chromatin DNA into nucleosomal fragments independently of caspases. Therefore, endoG represents a caspase-independent apoptotic pathway initiated from the mitochondria. A comprehensive understanding of the immune and genetic events that occur during VL is very important for designing immunotherapy strategies and developing effective vaccines for disease prevention. In this review which explained the immunological responses and also the important factors that can contribute to parasite apoptosis and are used in subsequent studies as a target for the preparation of drugs or recombinant vaccines against parasites are briefly reviewed.
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Affiliation(s)
- Mehdi Azami
- Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Hossein Khanahmad
- Department of Molecular Biology and Genetics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Ali Mohaghegh
- Department of Laboratory Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.,Health Sciences Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Ebtesam Zaherinejad
- School of Pharmacy, Department of Health Sciences, Curtin University of Technology, Bentley Campus, Australia
| | - Maryam Aghaei
- Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Akram Jalali
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Hossein Hejazi
- Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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15
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Uncovering Genomic Regions Associated with Trypanosoma Infections in Wild Populations of the Tsetse Fly Glossina fuscipes. G3-GENES GENOMES GENETICS 2018; 8:887-897. [PMID: 29343494 PMCID: PMC5844309 DOI: 10.1534/g3.117.300493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Vector-borne diseases are responsible for > 1 million deaths every year but genomic resources for most species responsible for their transmission are limited. This is true for neglected diseases such as sleeping sickness (Human African Trypanosomiasis), a disease caused by Trypanosoma parasites vectored by several species of tseste flies within the genus Glossina. We describe an integrative approach that identifies statistical associations between trypanosome infection status of Glossina fuscipes fuscipes (Gff) flies from Uganda, for which functional studies are complicated because the species cannot be easily maintained in laboratory colonies, and ∼73,000 polymorphic sites distributed across the genome. Then, we identify candidate genes involved in Gff trypanosome susceptibility by taking advantage of genomic resources from a closely related species, G. morsitans morsitans (Gmm). We compiled a comprehensive transcript library from 72 published and unpublished RNAseq experiments of trypanosome-infected and uninfected Gmm flies, and improved the current Gmm transcriptome assembly. This new assembly was then used to enhance the functional annotations on the Gff genome. As a consequence, we identified 56 candidate genes in the vicinity of the 18 regions associated with Trypanosoma infection status in Gff. Twenty-nine of these genes were differentially expressed (DE) among parasite-infected and uninfected Gmm, suggesting that their orthologs in Gff may correlate with disease transmission. These genes were involved in DNA regulation, neurophysiological functions, and immune responses. We highlight the power of integrating population and functional genomics from related species to enhance our understanding of the genetic basis of physiological traits, particularly in nonmodel organisms.
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Partida-Rodríguez O, Serrano-Vázquez A, Nieves-Ramírez ME, Moran P, Rojas L, Portillo T, González E, Hernández E, Finlay BB, Ximenez C. Human Intestinal Microbiota: Interaction Between Parasites and the Host Immune Response. Arch Med Res 2017; 48:690-700. [PMID: 29290328 DOI: 10.1016/j.arcmed.2017.11.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023]
Abstract
The human gut is a highly complex ecosystem with an extensive microbial community, and the influence of the intestinal microbiota reaches the entire host organism. For example, the microbiome regulates fat storage, stimulates or renews epithelial cells, and influences the development and maturation of the brain and the immune system. Intestinal microbes can protect against infection by pathogenic bacteria, viruses, fungi and parasites. Hence, the maintenance of homeostasis between the gut microbiota and the rest of the body is crucial for health, with dysbiosis affecting disease. This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. Although the mechanisms governing the interaction between intestinal microbiota and protozoa are poorly understood, it is known that the composition of the intestinal bacterial populations modulates the progression of protozoan infection and the outcome of parasitic disease. Most reports on the complex interactions between intestinal bacteria, protozoa and the immune system emphasize the protective role of the microbiota against protozoan infection. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered.
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Affiliation(s)
- Oswaldo Partida-Rodríguez
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México; Michael Smith Laboratories, University of Brithish Columbia, Vancouver, Canada
| | - Angélica Serrano-Vázquez
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Miriam E Nieves-Ramírez
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Patricia Moran
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Liliana Rojas
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Tobias Portillo
- Unidad de Bioinformática, Bioestadística y Biología Computacional. Red de Apoyo a la Investigación Científica, Universidad Nacional Autónoma de México, Instituto Nacional De Ciencias Médicas y Nutrición Salvador Zubirán, Ciudad de México, México
| | - Enrique González
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Eric Hernández
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - B Brett Finlay
- Michael Smith Laboratories, University of Brithish Columbia, Vancouver, Canada
| | - Cecilia Ximenez
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México.
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In vitro selection of Phytomonas serpens cells resistant to the calpain inhibitor MDL28170: alterations in fitness and expression of the major peptidases and efflux pumps. Parasitology 2017; 145:355-370. [PMID: 29039273 DOI: 10.1017/s0031182017001561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The species Phytomonas serpens is known to express some molecules displaying similarity to those described in trypanosomatids pathogenic to humans, such as peptidases from Trypanosoma cruzi (cruzipain) and Leishmania spp. (gp63). In this work, a population of P. serpens resistant to the calpain inhibitor MDL28170 at 70 µ m (MDLR population) was selected by culturing promastigotes in increasing concentrations of the drug. The only relevant ultrastructural difference between wild-type (WT) and MDLR promastigotes was the presence of microvesicles within the flagellar pocket of the latter. MDLR population also showed an increased reactivity to anti-cruzipain antibody as well as a higher papain-like proteolytic activity, while the expression of calpain-like molecules cross-reactive to anti-Dm-calpain (from Drosophila melanogaster) antibody and calcium-dependent cysteine peptidase activity were decreased. Gp63-like molecules also presented a diminished expression in MDLR population, which is probably correlated to the reduction in the parasite adhesion to the salivary glands of the insect vector Oncopeltus fasciatus. A lower accumulation of Rhodamine 123 was detected in MDLR cells when compared with the WT population, a phenotype that was reversed when MDLR cells were treated with cyclosporin A and verapamil. Collectively, our results may help in the understanding of the roles of calpain inhibitors in trypanosomatids.
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No evidence for manipulation of Anopheles gambiae, An. coluzzii and An. arabiensis host preference by Plasmodium falciparum. Sci Rep 2017; 7:9415. [PMID: 28842622 PMCID: PMC5572726 DOI: 10.1038/s41598-017-09821-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023] Open
Abstract
Whether malaria parasites can manipulate mosquito host choice in ways that enhance parasite transmission toward suitable hosts and/or reduce mosquito attraction to unsuitable hosts (i.e. specific manipulation) is unknown. To address this question, we experimentally infected three species of mosquito vectors with wild isolates of the human malaria parasite Plasmodium falciparum, and examined the effects of immature and mature infections on mosquito behavioural responses to combinations of calf odour, human odour and outdoor air using a dual-port olfactometer. Regardless of parasite developmental stage and mosquito species, P. falciparum infection did not alter mosquito activation rate or their choice for human odours. The overall expression pattern of host choice of all three mosquito species was consistent with a high degree of anthropophily, with infected and uninfected individuals showing higher attraction toward human odour over calf odour, human odour over outdoor air, and outdoor air over calf odour. Our results suggest that, in this system, the parasite may not be able to manipulate the early long-range behavioural steps involved in the mosquito host-feeding process. Future studies are required to test whether malaria parasites can modify their mosquito host choice at a shorter range to enhance transmission.
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Enterocin AS-48 as Evidence for the Use of Bacteriocins as New Leishmanicidal Agents. Antimicrob Agents Chemother 2017; 61:AAC.02288-16. [PMID: 28167557 DOI: 10.1128/aac.02288-16] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/02/2017] [Indexed: 11/20/2022] Open
Abstract
We report the feasibility of enterocin AS-48, a circular cationic peptide produced by Enterococcus faecalis, as a new leishmanicidal agent. AS-48 is lethal to Leishmania promastigotes as well as to axenic and intracellular amastigotes at low micromolar concentrations, with scarce cytotoxicity to macrophages. AS-48 induced a fast bioenergetic collapse of L. donovani promastigotes but only a partial permeation of their plasma membrane with limited entrance of vital dyes, even at concentrations beyond its full lethality. Fluoresceinated AS-48 was visualized inside parasites by confocal microscopy and seen to cause mitochondrial depolarization and reactive oxygen species production. Altogether, AS-48 appeared to have a mixed leishmanicidal mechanism that includes both plasma membrane permeabilization and additional intracellular targets, with mitochondrial dysfunctionality being of special relevance. This complex leishmanicidal mechanism of AS-48 persisted even for the killing of intracellular amastigotes, as evidenced by transmission electron microscopy. We demonstrated the potentiality of AS-48 as a new and safe leishmanicidal agent, expanding the growing repertoire of eukaryotic targets for bacteriocins, and our results provide a proof of mechanism for the search of new leishmanicidal bacteriocins, whose diversity constitutes an almost endless source for new structures at moderate production cost and whose safe use on food preservation is well established.
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