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Parasitology Research Apr 2019For years, mammals of the order Pilosa have been considered Leishmania reservoirs. But while most studies have focused on sloth species, anteaters have been overlooked,... (Review)
Review
For years, mammals of the order Pilosa have been considered Leishmania reservoirs. But while most studies have focused on sloth species, anteaters have been overlooked, and in many Leishmania endemic countries like Mexico, no studies have been carried out. The aims of this work were to identify the presence of Leishmania spp. in tissue samples from road-killed northern tamanduas (Tamandua mexicana), using PCR amplification and sequencing of ITS1 DNA, and to discuss the role of Pilosa mammals as reservoirs of Leishmania based on available scientific records. This is the first study that identifies Leishmania in T. mexicana, from 1 of 16 individuals analyzed, so the estimated prevalence (CI 95%) of infection was 6.3% (0.3-27.2). Amplified sequence exhibited a 98.9% (727/735) similarity with L. mexicana, and phylogenetic analysis grouped the species in the L. mexicana-amazonensis cluster. The literature review revealed 241 cases of Leishmania spp. infection among 1219 Pilosa mammals evaluated, with prevalence between studies ranging from 3.5% in the brown-throated three-toed sloth (Bradypus variegatus) to 78% in the Hoffman's two-toed sloth (Choloepus hoffmanni). Current scientific information indicates that C. hoffmanni sloths are reservoirs of Leishmania, and further studies are needed in order to clarify if other Pilosa species play a role in Leishmania transmission.
Topics: Animals; DNA, Protozoan; Disease Reservoirs; Leishmania mexicana; Leishmaniasis; Mexico; Phylogeny; Sloths; Xenarthra
PubMed: 30770980
DOI: 10.1007/s00436-019-06253-6 -
Virulence Dec 2021Catalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The...
Catalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The catalase-encoding gene is conspicuously absent from the genome of most representatives of the family Trypanosomatidae. Here, we expressed this protein from the locus using a novel bicistronic expression system, which relies on the 2A peptide of . We demonstrated that catalase-expressing parasites are severely compromised in their ability to develop in insects, to be transmitted and to infect mice, and to cause clinical manifestation in their mammalian host. Taken together, our data support the hypothesis that the presence of catalase is not compatible with the dixenous life cycle of , resulting in loss of this gene from the genome during the evolution of these parasites.
Topics: Animals; Catalase; Cells, Cultured; Female; Leishmania mexicana; Life Cycle Stages; Mice; Mice, Inbred BALB C; Protozoan Proteins; Psychodidae; Teschovirus; Virulence; Virulence Factors
PubMed: 33724149
DOI: 10.1080/21505594.2021.1896830 -
Journal of Immunology Research 2020Exosomes are extracellular microvesicles of endosomal origin (multivesicular bodies, MVBs) constitutively released by eukaryotic cells by fusion of MVBs to the plasma...
Exosomes are extracellular microvesicles of endosomal origin (multivesicular bodies, MVBs) constitutively released by eukaryotic cells by fusion of MVBs to the plasma membrane. The exosomes from parasites contain an array of parasite molecules such as virulence factors and survival messengers, capable of modulating the host immune response and thereby favoring the infection of the host. We here show that exosomes of amastigotes (aExo) contain the virulence proteins gp63 and PP2C. The incubation of aExo with bone marrow-derived macrophages (BMMs) infected with led to their internalization and were found to colocalize with the cellular tetraspanin CD63. Furthermore, aExo inhibited nitric oxide production of infected BMMs, permitting enhanced intracellular parasite survival. Expressions of antigen-presenting (major histocompatibility complex class I, MHC-I, and CD1d) and costimulatory (CD86 and PD-L1) molecules were modulated in a dose-dependent fashion. Whereas MHC-I, CD86 and PD-L1 expressions were diminished by exosomes, CD1d was enhanced. We conclude that aExo of are capable of decreasing microbicidal mechanisms of infected macrophages by inhibiting nitric oxide production, thereby enabling parasite survival. They also hamper the cellular immune response by diminishing MHC-I and CD86 on an important antigen-presenting cell, which potentially interferes with CD8 T cell activation. The enhanced CD1d expression in combination with reduction of PD-L1 on BMMs point to a potential shift of the activation route towards lipid presentations, yet the effectivity of this immune activation is not evident, since in the absence of costimulatory molecules, cellular anergy and tolerance would be expected.
Topics: Animals; Biomarkers; Cells, Cultured; Disease Models, Animal; Exosomes; Host-Pathogen Interactions; Leishmania mexicana; Leishmaniasis, Cutaneous; Mice
PubMed: 33344659
DOI: 10.1155/2020/8894549 -
Molecules (Basel, Switzerland) Sep 2019Leishmanicidal drugs have many side effects, and drug resistance to all of them has been documented. Therefore, the development of new drugs and the identification of...
Leishmanicidal drugs have many side effects, and drug resistance to all of them has been documented. Therefore, the development of new drugs and the identification of novel therapeutic targets are urgently needed. trypanothione reductase (LmTR), a NADPH-dependent flavoprotein oxidoreductase important to thiol metabolism, is essential for parasite viability. Its absence in the mammalian host makes this enzyme an attractive target for the development of new anti- drugs. Herein, a tridimensional model of LmTR was constructed and the molecular docking of 20 molecules from a ZINC database was performed. Five compounds (ZINC04684558, ZINC09642432, ZINC12151998, ZINC14970552, and ZINC11841871) were selected (docking scores -10.27 kcal/mol to -5.29 kcal/mol and structurally different) and evaluated against recombinant LmTR (rLmTR) and promastigote. Additionally, molecular dynamics simulation of LmTR-selected compound complexes was achieved. The five selected compounds inhibited rLmTR activity in the range of 32.9% to 40.1%. The binding of selected compounds to LmTR involving different hydrogen bonds with distinct residues of the molecule monomers A and B is described. Compound ZINC12151998 (docking score -10.27 kcal/mol) inhibited 32.9% the enzyme activity (100 µM) and showed the highest leishmanicidal activity (IC = 58 µM) of all the selected compounds. It was more active than glucantime, and although its half-maximal cytotoxicity concentration (CC = 53 µM) was higher than that of the other four compounds, it was less cytotoxic than amphotericin B. Therefore, compound ZINC12151998 provides a promising starting point for a hit-to-lead process in our search for new anti- drugs that are more potent and less cytotoxic.
Topics: Amino Acid Sequence; Binding Sites; Dose-Response Relationship, Drug; Enzyme Inhibitors; Hydrogen Bonding; Leishmania mexicana; Molecular Conformation; Molecular Docking Simulation; Molecular Dynamics Simulation; Molecular Structure; NADH, NADPH Oxidoreductases; Pharmacokinetics; Recombinant Proteins; Structure-Activity Relationship; Trypanocidal Agents
PubMed: 31487860
DOI: 10.3390/molecules24183216 -
Vector Borne and Zoonotic Diseases... Dec 2022Leishmaniases are a group of vector-borne zoonotic diseases of public health relevance within the tropical and subtropical regions of the world. The state of Yucatan is...
Leishmaniases are a group of vector-borne zoonotic diseases of public health relevance within the tropical and subtropical regions of the world. The state of Yucatan is a vulnerable and receptive area to localized cutaneous leishmaniasis (LCL) due to its proximity to the high-transmission endemic states of Campeche and Quintana Roo. Autochthonous cases of LCL caused by () have been documented in the state, showing a geographical expansion of the disease. Using CO-supplemented Centers for Disease Control and Prevention light traps and Shannon traps, we captured anthropophilic sandflies in the surroundings of a locality with recent records of autochthonous cases of LCL. Sandflies carrying DNA were evidenced using PCR. A total of 140 Phlebotominae (Diptera: Psychodidae) females of four species were captured: () (Coquillett), () (Dyar), () (Lutz and Neiva), and () (Fairchild and Hertig). Molecular results showed that 6.1% (95% confidence interval [CI] = 2.3-12.9%) of and 43.8% (95% CI = 19.8-70.1%) of showed evidence of carrying () DNA. We provide evidence of anthropophilic sandflies carrying DNA in a municipality with recorded autochthonous cases of LCL caused by this parasite species in the state of Yucatan, suggesting the emergence of new focus of LCL in Mexico.
Topics: Animals; Leishmania mexicana; Mexico; Psychodidae
PubMed: 36399687
DOI: 10.1089/vbz.2022.0045 -
Acta Tropica Mar 2020To elucidate the transmission mode of Andean cutaneous leishmaniasis (Andean-CL), natural Leishmania infection and biting activity of sand flies were tested in a...
To elucidate the transmission mode of Andean cutaneous leishmaniasis (Andean-CL), natural Leishmania infection and biting activity of sand flies were tested in a selected sylvatic focus of the endemic area of the Ecuadorian Andes. Monthly sand fly collections and dissections were conducted during 12 months from July 2018 to June 2019. The Leishmania positive specimens/slides with innumerable amounts of actively mobile flagellates made us easy to detect positive sand flies. The promastigotes observed located in the anterior and posterior midgut, without the hindgut localization. The parasite isolated was identified as L. (L.) mexicana by cytochrome b gene analysis. No other Leishmania or flagellate species parasitic in sand flies was observed in the area. Only Lu. ayacuchensis was caught throughout. Monthly microscopic examination of Lu. ayacuchensis revealed 0.75-8.33% of natural L. (L.) mexicana infection rates. Higher Leishmania infection months were present at the end of the wet season of the Andes, while higher sand fly numbers occurred during the dry season. Diurnal biting (blood meal seeking) activity of sand flies started around 17:30 before sunset, increased between 18:00 and 19:30, and thereafter decreased drastically probably because of low temperature (15-18 °C) in the area. The results provide information important for the planning of vector control strategy and management of the disease in the Andean-CL endemic area of Ecuador.
Topics: Animals; Ecuador; Humans; Insect Bites and Stings; Insect Vectors; Leishmania mexicana; Leishmaniasis, Cutaneous; Psychodidae
PubMed: 31877283
DOI: 10.1016/j.actatropica.2019.105321 -
Frontiers in Cellular and Infection... 2022is the unicellular parasite transmitted by phlebotomine sand fly bite. It exists in two different forms; extracellular promastigotes, occurring in the gut of sand...
is the unicellular parasite transmitted by phlebotomine sand fly bite. It exists in two different forms; extracellular promastigotes, occurring in the gut of sand flies, and intracellular, round-shaped amastigotes residing mainly in vertebrate macrophages. As amastigotes originating from infected animals are often present in insufficient quality and quantity, two alternative types of amastigotes were introduced for laboratory experiments: axenic amastigotes and amastigotes from macrophages infected . Nevertheless, there is very little information about the degree of similarity/difference among these three types of amastigotes on proteomic level, whose comparison is crucial for assessing the suitability of using alternative types of amastigotes in experiments. In this study, amastigotes obtained from lesion of infected BALB/c mice were proteomically compared with alternatively cultivated amastigotes (axenic and macrophage-derived ones). Amastigotes of all three types were isolated, individually treated and analysed by LC-MS/MS proteomic analysis with quantification using TMT-plex isobaric labeling. Significant differences were observed in the abundance of metabolic enzymes, virulence factors and proteins involved in translation and condensation of DNA. The most pronounced differences were observed between axenic amastigotes and lesion-derived amastigotes, macrophage-derived amastigotes were mostly intermediate between axenic and lesion-derived ones.
Topics: Mice; Animals; Leishmania mexicana; Proteome; Proteomics; Chromatography, Liquid; Tandem Mass Spectrometry; Mice, Inbred BALB C
PubMed: 36439224
DOI: 10.3389/fcimb.2022.1022448 -
Molecular and Biochemical Parasitology Sep 1999As a start to understanding the importance of intracellular proteolysis in the protozoon Leishmania mexicana, the parasite proteasome has been purified and...
As a start to understanding the importance of intracellular proteolysis in the protozoon Leishmania mexicana, the parasite proteasome has been purified and characterised. The L. mexicana proteasome is similar to proteasomes from other eukaryotes. It is soluble, and the 20S form has a mass of around 670 kDa, composed of at least 10 distinct subunits in the 22 to 32 kDa size range. The molecular mass of the L. mexicana proteasome increases to 1200 kDa in the presence of adenosine-5'-triphosphate, consistent with there being a 26S proteasome in the parasite. The purified 20S proteasome has activity towards substrates with hydrophobic, basic and acidic P, residues, and is sensitive to a range of peptide aldehyde inhibitors, as well as the proteasome-specific inhibitor lactacystin. The peptide aldehydes are able to arrest parasite growth in vitro with the same relative effectiveness as against the purified proteasome activity. The parasite population arrests with an increased 4N DNA content, indicating that, in part, the essential nature of the proteasome for L. mexicana proliferation is due to a role in the parasite cell cycle. Surprisingly, lactacystin is a relatively inefficient inhibitor of L. mexicana growth in vitro.
Topics: Acetylcysteine; Adenosine Triphosphate; Animals; Coumarins; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Leishmania mexicana; Molecular Weight; Multienzyme Complexes; Oligopeptides; Proteasome Endopeptidase Complex; Substrate Specificity
PubMed: 10514080
DOI: 10.1016/s0166-6851(99)00110-3 -
Cell Stress & Chaperones Jul 2018Parasites of the Leishmania genus, which are the causative agents of leishmaniasis, display a complex life cycle, from a flagellated form (promastigotes) residing in the...
Parasites of the Leishmania genus, which are the causative agents of leishmaniasis, display a complex life cycle, from a flagellated form (promastigotes) residing in the midgut of the phlebotomine vector to a non-flagellated form (amastigote) invading the mammalian host. The cellular process for the conversion between these forms is an interesting biological phenomenon involving modulation of the plasma membrane. In this study, we describe a selective autophagic-like process during the in vitro differentiation of Leishmania mexicana promastigote to amastigote-like cells. This process is responsible for size reduction and shape change of the promastigote (15-20 μm long) to the rounded amastigote-like form (4-5 μm long), identical to the one that infects host macrophages. This autophagic-like process is characterized by a profound folding of the plasma membrane and the presence of abundant cytoplasmic lipid droplets that may be the product of changes in the lipid metabolism. The key feature for the differentiation process at either pH 7.0 or pH 5.5 is the shift in temperature from 25 to 35 °C. Flagella shortening during the differentiation process appears as the product of continuous flagellar microtubular disassembly that is also accompanied by changes in mitochondrion localization. Drugs directed at blocking the parasite autophagic-like process could be important as new strategies to fight the disease.
Topics: Autophagy; Cell Differentiation; Cell Membrane; Flagella; Heat-Shock Response; Hydrogen-Ion Concentration; Leishmania mexicana; Life Cycle Stages
PubMed: 29170928
DOI: 10.1007/s12192-017-0864-z -
Molecular and Biochemical Parasitology Jun 2019The kinetoplastids Trypanosoma brucei and Leishmania mexicana are eukaryotes with a highly structured cellular organisation that is reproduced with great fidelity in...
The kinetoplastids Trypanosoma brucei and Leishmania mexicana are eukaryotes with a highly structured cellular organisation that is reproduced with great fidelity in each generation. The pattern of signal from a fluorescently tagged protein can define the specific structure/organelle that this protein localises to, and can be extremely informative in phenotype analysis in experimental perturbations, life cycle tracking, post-genomic assays and functional analysis of organelles. Using the vast coverage of protein subcellular localisations provided by the TrypTag project, an ongoing project to determine the localisation of every protein encoded in the T. brucei genome, we have generated an inventory of reliable reference organelle markers for both parasites that combines epifluorescence images with a detailed description of the key features of each localisation. We believe this will be a useful comparative resource that will enable researchers to quickly and accurately pinpoint the localisation of their proteins of interest and will provide cellular markers for many types of cell biology studies. We see this as another important step in the post-genomic era analyses of these parasites, in which ever expanding datasets generate numerous candidates to analyse. Adoption of these reference proteins by the community is likely to enhance research studies and enable better comparison of data.
Topics: Leishmania mexicana; Microscopy, Fluorescence; Organelles; Protein Transport; Protozoan Proteins; Recombinant Fusion Proteins; Staining and Labeling; Trypanosoma brucei brucei
PubMed: 30550896
DOI: 10.1016/j.molbiopara.2018.12.003