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Transgenic leishmania

Carlos A Nieto, Lina M Sánchez, Diana M Sánchez, Gonzalo J Díaz, María H Ramírez
BACKGROUND: Nicotinamide adenine dinucleotide (NAD+) is an essential molecule in the energy metabolism of living beings, and it has various cellular functions. The main enzyme in the biosynthesis of this nucleotide is nicotinamide/nicotinate mononucleotide adenylyltransferase (NMNAT, EC because it is the convergence point for all known biosynthetic pathways. NMNATs have divergences in both the number of isoforms detected and their distribution, depending on the organism. METHODS: In the laboratory of basic research in biochemistry (LIBBIQ: acronym in Spanish) the NMNATs of protozoan parasites (Leishmania braziliensis, Plasmodium falciparum, Trypanosoma cruzi, and Giardia duodenalis) have been studied, analysing their catalytic properties through the use of proteins...
April 11, 2018: Malaria Journal
Ana Paula M M Almeida, Leopoldo F M Machado, Daniel Doro, Frederico C Nascimento, Leonardo Damasceno, Ricardo Tostes Gazzinelli, Ana Paula Fernandes, Caroline Junqueira
Visceral leishmaniasis (VL) is a major public health issue reported as the second illness in mortality among all tropical diseases. Clinical trials have shown that protection against VL is associated with robust T cell responses, especially those producing IFN-γ. The Leishmania amastigote 2 (A2) protein has been repeatedly described as immunogenic and protective against VL in different animal models; it is recognized by human T cells, and it is also commercially available in a vaccine formulation containing saponin against canine VL...
2018: Frontiers in Immunology
Rodrigo Saar Gomes, Muriel Vilela Teodoro Silva, Jéssica Cristina Dos Santos, Christine van Linge, Juliana Machado Reis, Mauro Martins Teixeira, Sebastião Alves Pinto, Miriam Leandro Dorta, Xiyuan Bai, Edward D Chan, Charles A Dinarello, Milton Adriano Pelli Oliveira, Leo A B Joosten, Fátima Ribeiro-Dias
Visceral leishmaniasis (VL) is a chronic parasitic disease caused by Leishmania infantum in the Americas. During VL, several proinflammatory cytokines are produced in spleen, liver, and bone marrow. However, the role of interleukin-32 (IL-32) has not been explored in this disease. IL-32 can induce production of proinflammatory cytokines in innate immune cells and polarize the adaptive immune response. Herein, we discovered that L. infantum antigens induced expression of mRNA mainly for the IL-32γ isoform but also induced low levels of the IL-32β transcript in human peripheral blood mononuclear cells...
May 2018: Infection and Immunity
Sayonara M Viana, Fabiana S Celes, Laura Ramirez, Bala Kolli, Dennis K P Ng, Kwang P Chang, Camila I de Oliveira
Background: Photosensitizers (PS), like porphyrins and phthalocyanines (PC) are excitable by light to generate cytotoxic singlet oxygen and other reactive oxygen species in the presence of atmospheric O2 . Photodynamic inactivation of Leishmania by this means renders them non-viable, but preserves their effective use as vaccines. Leishmania can be photo-inactivated after PS-sensitization by loading via their endocytic uptake of PC or endogenous induction of transgenic mutants with delta-aminolevulinate (ALA) to accumulate cytosolic uroporphyrin I (URO)...
2018: Frontiers in Microbiology
Hafiz Shoaib Sarwar, Muhammad Farhan Sohail, Noushin Saljoughian, Anees Ur Rehman, Sohail Akhtar, Akhtar Nadhman, Masoom Yasinzai, Howard E Gendelman, Abhay R Satoskar, Gul Shahnaz
The aim of this study was to evaluate mannose-anchored thiolated chitosan (MTC) based nanocarriers (NCs) for enhanced permeability, improved oral bioavailability and anti-parasitic potential of amphotericin B (AmB). Transgenic Leishmania donovani parasites expressing red fluorescent protein DsRed2 and imaging-flow cytometry was used to investigate parasitic burdens inside bone marrow-derived macrophages ex vivo. Cytokine estimation revealed that MTC nanocarriers activated the macrophages to impart an explicit immune response by higher production of TNF-α and IL-12 as compared to control...
January 31, 2018: Artificial Cells, Nanomedicine, and Biotechnology
Erin A Brettmann, Lon-Fye Lye, Stephen M Beverley
An essential control for genetic manipulation of microbes is the regeneration of the wild-type state and phenotype to validate that any mutant phenotypes are 'on target'. For Leishmania gene knockouts, this is often done by re-expression of the target gene from episomal vectors, often bearing counter-selectable markers. Methods for similarly validating the outcomes from dominant mutations such as those arising from RNA interference (RNAi) are needed. We present here such an approach, relying on facilitated recovery after spontaneous excision - or 'popouts' - of dominant transgenes stably inserted into the ribosomal RNA array, utilizing GFP as a marker and single cell sorting to recover regenerated WT controls...
March 2018: Molecular and Biochemical Parasitology
Estefania Calvo-Alvarez, Christelle Cren-Travaillé, Aline Crouzols, Brice Rotureau
Trypanosomiases and leishmaniases, caused by a group of related protist parasites, are Neglected Tropical Diseases currently threatening >500 million people worldwide. Reporter proteins have revolutionised the research on infectious diseases and have opened up new advances in the understanding of trypanosomatid-borne diseases in terms of both biology, pathogenesis and drug development. Here, we describe the generation and some applications of a new chimeric triple reporter fusion protein combining the red-shifted firefly luciferase PpyREH9 and the tdTomato red fluorescent protein, fused by the TY1 tag...
January 25, 2018: Infection, Genetics and Evolution
Tahereh Donyavi, Mojgan Bandehpour, Bahram Kazemi
Background and Objectives: Leishmania are intracellular flagellate protozoan parasites cause a wide spectrum of clinical manifestations in human. The immunological basis for resistance against leishmaniasis depends on Thl responses in the course of performance of cytokines like IL-12. In this study, a transgenic Leishmania coding human IL-12 was produced that can be used in Leishmanization. Materials and Methods: A fragment of Iranian lizard Leishmania (I.L.L) gene, named Cysteine Peptidase C (CPC), was amplified separately as two parts with PCR reaction...
October 2017: Iranian Journal of Microbiology
Eva Iniguez, Nathaniel S Schocker, Krishanthi Subramaniam, Susana Portillo, Alba L Montoya, Waleed S Al-Salem, Caresse L Torres, Felipe Rodriguez, Otacilio C Moreira, Alvaro Acosta-Serrano, Katja Michael, Igor C Almeida, Rosa A Maldonado
BACKGROUND: Protozoan parasites from the genus Leishmania cause broad clinical manifestations known as leishmaniases, which affect millions of people worldwide. Cutaneous leishmaniasis (CL), caused by L. major, is one the most common forms of the disease in the Old World. There is no preventive or therapeutic human vaccine available for L. major CL, and existing drug treatments are expensive, have toxic side effects, and resistant parasite strains have been reported. Hence, further therapeutic interventions against the disease are necessary...
October 2017: PLoS Neglected Tropical Diseases
Zahra Abdossamadi, Tahereh Taheri, Negar Seyed, Hossein Montakhab-Yeganeh, Farnaz Zahedifard, Yasaman Taslimi, Sima Habibzadeh, Elham Gholami, Safoora Gharibzadeh, Sima Rafati
AIM: Several disadvantages about chemotherapy for leishmaniasis has reinforced discovery of novel therapeutic agents especially immunotherapeutics. HNP1, as a member of the mammalian antimicrobial peptides family, is an attractive molecule due to its broad functional spectrum. Here, the in vivo potency of HNP1 in transgenic Leishmania tarentolae as an immunotherapy tool against Leishmania major-infected BALB/c mice was examined. METHODS & RESULTS: 3 weeks after infection with L...
October 2017: Immunotherapy
José Miguel Escudero-Martínez, Yolanda Pérez-Pertejo, Rosa M Reguera, María Ángeles Castro, María Victoria Rojo, Carolina Santiago, Andrés Abad, Pablo Anselmo García, José Luis López-Pérez, Arturo San Feliciano, Rafael Balaña-Fouce
Leishmania microtubules play an important role not only in cell division, but also in keeping the shape of the parasite and motility of its free-living stages. Microtubules result from the self-assembly of alpha and beta tubulins, two phylogenetically conserved and very abundant eukaryotic proteins in kinetoplastids. The colchicine binding domain has inspired the discovery and development of several drugs currently in clinical use against parasites. However, this domain is less conserved in kinetoplastids and may be selectively targeted by new compounds...
December 2017: International Journal for Parasitology, Drugs and Drug Resistance
Rodrigo Saar Gomes, Muriel Vilela Teodoro Silva, Jéssica Cristina Dos Santos, Lucas Luiz de Lima Silva, Aline Carvalho Batista, Juliana Reis Machado, Mauro Martins Teixeira, Miriam Leandro Dorta, Milton Adriano Pelli de Oliveira, Charles A Dinarello, Leo A B Joosten, Fátima Ribeiro-Dias
BACKGROUND: Interleukin 32 (IL-32) is a pro-inflammatory cytokine induced in patients with American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis. Here, we investigated whether IL-32 is also expressed in patient lesions caused by L. amazonensis. In addition, we evaluated experimental L. amazonensis and L. braziliensis infections in C57BL/6 transgenic mice for human IL-32γ (IL-32γTg) in comparison with wild-type (WT) mice that do not express the IL-32 gene. RESULTS: Human cutaneous lesions caused by L...
July 14, 2017: Parasites & Vectors
Evita Athanasiou, Maria Agallou, Spyros Tastsoglou, Olga Kammona, Artemis Hatzigeorgiou, Costas Kiparissides, Evdokia Karagouni
Visceral leishmaniasis, caused by Leishmania (L.) donovani and L. infantum protozoan parasites, can provoke overwhelming and protracted epidemics, with high case-fatality rates. An effective vaccine against the disease must rely on the generation of a strong and long-lasting T cell immunity, mediated by CD4(+) TH1 and CD8(+) T cells. Multi-epitope peptide-based vaccine development is manifesting as the new era of vaccination strategies against Leishmania infection. In this study, we designed chimeric peptides containing HLA-restricted epitopes from three immunogenic L...
2017: Frontiers in Immunology
Smriti Parashar, Amitabha Mukhopadhyay
Metalloprotease gp63 ( Leishmania donovani gp63 (Ldgp63)) is a critical virulence factor secreted by Leishmania However, how newly synthesized Ldgp63 exits the endoplasmic reticulum (ER) and is secreted by this parasite is unknown. Here, we cloned, expressed, and characterized the GTPase LdSar1 and other COPII components like LdSec23, LdSec24, LdSec13, and LdSec31 from Leishmania to understand their role in ER exit of Ldgp63. Using dominant-positive (LdSar1:H74L) and dominant-negative (LdSar1:T34N) mutants of LdSar1, we found that GTP-bound LdSar1 specifically binds to LdSec23, which binds, in turn, with LdSec24(1-702) to form a prebudding complex...
July 21, 2017: Journal of Biological Chemistry
Matheus Batista Carneiro, Leah Shan Hohman, Jackson G Egen, Nathan C Peters
Intra-vital two-photon microscopy (2P-IVM) allows for in-situ investigation of tissue organization, cell behavior and the dynamic interactions between different cell types in their natural environment. This methodology has also expanded our understanding of the immune response against pathogens. Leishmania are protozoan intracellular parasites that have adapted to successfully establish infection within the context of an inflammatory response in the skin following transmission by the bite of an infected sand fly...
April 19, 2017: Methods: a Companion to Methods in Enzymology
Pedro H F Stroppa, Luciana M R Antinarelli, Arturene M L Carmo, Jacy Gameiro, Elaine S Coimbra, Adilson D da Silva
Here, we report the effect of new non-classical bioisosteres of miltefosine on Leishmania amazonensis. Fifteen compounds were synthesized and the compound dhmtAc, containing an acetate anion, a side chain of 10 carbon atoms linked to N-1 and a methyl group linked to N-3, showed high and selective biological activity against L. amazonensis. On the intracellular amastigotes, stages of the parasite related to human disease, the IC50 values were near or similar to the 1.0μM (0.9, 0.8 and 1.0μM on L. amazonensis-WT, and two transgenic L...
June 15, 2017: Bioorganic & Medicinal Chemistry
Andrés Vacas, Conor Sugden, Óscar Velasco-Rodriguez, Miriam Algarabel-Olona, José Peña-Guerrero, Esther Larrea, Celia Fernández-Rubio, Paul A Nguewa
Leishmania is the causative agent of leishmaniasis, a neglected tropical disease that affects more than 12 million people around the world. Current treatments are toxic and poorly effective due to the acquisition of resistance within Leishmania populations. Thus, the pursuit for new antileishmanial drugs is a priority. The available methods for drug screening based on colorimetric assays using vital dyes are time-consuming. Currently, the use of fluorescent reporter proteins is replacing the use of viability indicator dyes...
2017: Journal of Parasitology Research
Neeradi Dinesh, Soumya Neelagiri, Vinay Kumar, Sushma Singh
In the present study, glycyrrhizic acid (GA) the main component of Glycyrrhiza glabra was evaluated for its efficacy as antileishmanial agent and its mode of action explored. GA inhibits promastigotes and intracellular amastigotes in a dose dependent manner at an IC50 value of 34 ± 3.0 μM and 20 ± 4.2 μM respectively. GA was non-toxic against THP-1 macrophage host cell line. GA was found to inhibit recombinant Leishmania donovani HMG-CoA reductase (LdHMGR) enzyme at the half-maximum inhibitory concentration of 24 ± 4...
May 2017: Experimental Parasitology
Isabelle Legastelois, Sophie Buffin, Isabelle Peubez, Charlotte Mignon, Régis Sodoyer, Bettina Werle
The increasing demand for recombinant vaccine antigens or immunotherapeutic molecules calls into question the universality of current protein expression systems. Vaccine production can require relatively low amounts of expressed materials, but represents an extremely diverse category consisting of different target antigens with marked structural differences. In contrast, monoclonal antibodies, by definition share key molecular characteristics and require a production system capable of very large outputs, which drives the quest for highly efficient and cost-effective systems...
April 3, 2017: Human Vaccines & Immunotherapeutics
Amjad Hayat Khan, Hadi Bayat, Masoumeh Rajabibazl, Suriana Sabri, Azam Rahimpour
Glycosylation represents the most widespread posttranslational modifications, found in a broad spectrum of natural and therapeutic recombinant proteins. It highly affects bioactivity, site-specificity, stability, solubility, immunogenicity, and serum half-life of glycoproteins. Numerous expression hosts including yeasts, insect cells, transgenic plants, and mammalian cells have been explored for synthesizing therapeutic glycoproteins. However, glycosylation profile of eukaryotic expression systems differs from human...
January 2017: World Journal of Microbiology & Biotechnology
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