جستجوی مقالات مرتبط با کلیدواژه « leishmania » در نشریات گروه « پزشکی »

In eukaryotes, translation is a fundamental step in the long pathway of protein synthesis within the cell. In this process, several proteins and factors have involved directly or indirectly, individually or in association with other elements to contact mRNA. For perfect translation, many essential modifications should be done, such as cis-splicing to remove introns and two main events for capping and poly A polymerization in 5’ and 3’ end of mRNA, respectively. Gene expression is then regulated at both translation and stability of the target mRNA molecule levels. Pumilio/ FBFs (PUFs) are the main group of RNA-binding proteins which bind to the 3’-UTR of target RNA and thereby regulate the fate, stability and subcellular localization of mRNAs and adjust the translated protein level. PUF proteins have been found both in nucleus where that bind to precursor mRNA, for processing and maturation of rRNA, and in cytoplasm where that bind to mRNA, stall the ribosomes, suppress the translation and localization of the mRNA. They can regulate the expression of mRNAs through activation or suppression of translation. Therefore, these proteins have recently garnered much attention as new generation of therapeutic targets against diseases such as cancer and neurological disorders. In comparison to other eukaryotes, trypanosomatids have a high number of PUF proteins, which function not only as gene expression regulatory factors but also in several biological processes such as differentiation and life-cycle progression of the cells. Here, we review the molecular and biological roles of known PUF proteins in TriTryp parasites (Trypanosome brucei, T. cruzi and Leishmania) beside some other parasites.

The lack of complete protection against leishmaniasis and the challenges of anti-leishmaniasis drug treatment have made the treatment process more difficult. This study aimed to develop a new strategy for preparing a vaccine against cutaneous leishmaniasis using some of the antigenic proteins of the Leishmania parasite.

This study was carried out in 2022 at Shahid Chamran University of Ahvaz, Ahvaz, Iran. After preparing suitable epitopes of the Leishmania parasite and examining their antiparasitic properties, the process of making a fusion vaccine was performed and with the help of various bioinformatics tools, physicochemical and structural properties as well as immunological and simulation properties were studied and finally optimized. Construction and cloning were performed in the E.coli K12 system and finally, the docking process was performed with Toll-like receptors (TLRs), major histocompatibility complex I (MHC-I), and MHC-II receptors. With the help of selected epitopes of the Leishmania parasite, which had a high percentage of population coverage, a stable, antigenic, and non-allergenic chimeric vaccine was predicted.

The results of the structural analysis of the TLR5\vaccine complex and simulation of its molecular dynamics showed a sufficiently stable binding. It also showed good potential for stimulation and production of active B cells and memory, as well as the potential for CD8+ T, CD4+ T cell production and development of Th2 and Th1-induced immune responses.

Computational results showed that the designed immunogenic structure has the potential to adequately stimulate cellular and humoral immune responses against Leishmania parasitic disease. As a result of evaluating the effectiveness of the candidate vaccine through in vivo and in vitro immunological tests, it can be suggested as a vaccine against Leishmania major.

Alliums are rich sources of steroidal saponins, flavonoids, and sulphoric compounds of which steroidal saponins have recently received more attention due to their important pharmacological activities. Allium giganteum (giant onion) which is named locally “Couria” in the Northeast of Iran, is grown widely in “Kouh-Sorkh” mountains in Khorasan province.

Experimental approach: 

Phytochemical investigation of chloroform-methanol and aqueous extract of the plant resulted in the isolation and identification of two steroidal saponins, using comprehensive spectroscopic methods including 1D and 2D NMR and MS.

The chemical structures of the isolated saponins were determined as (22S)-cholesta- 1b,3b,16b,22b-tetraol 5-en, and 3-O-β-D-glucopyranosyl 26-O-β-D-glucopyranosside and (25R)-26-O-β-Dglucopyranosyl- 5α-furostan-1α,3β,22α,26-tetraol3-O-{β-D-galactopyranosyl-(1→2)-O-[β-D-xylopyranosyl- (1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside}. Investigation of in vitro antileishmanial activity of the isolated compounds at 10, 50, and 100 μg/mL exhibited significant leishmanicidal against the promastigotes of Leishmania major.

Conclusion and implications: 

The results established a valuable basis for further studies about A. giganteum and the anti-parasitic activity of steroidal saponins.

Leishmania is a vector-borne protozoon, which causes visceral, cutaneous and mucocutaneous leishmaniosis in human and animals. Monocyte- derived exosome vaccines can be used as prophylaxis and immunotherapy strategies. The aim of this study was to design a multiple-epitope candidate vaccine using leishmaniolysin (GP63) and rK39 proteins against Leishmania major and L. infantum for monocyte-derived exosome preparation.

This study was carried out in Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran, 2023–2024. Effective immunodominant epitopes were selected from two antigenic proteins of GP63 and rK39 using various immunoinformatics and bioinformatics approaches. Vibrio cholerae β- subunit was used as an adjuvant to stimulate immune responses. Then, appropriate linkers were selected for the fusion of epitopes. The 3D model of candidate vaccine was predicted and validated.

This designed candidate vaccine could effectively be used as a prophylaxis strategy against leishmaniosis.

A candidate vaccine was designed using bioinformatic and immunoinformatic studies with virtual acceptable quality; however, effectiveness of this vaccine should be verified through further in-vitro and in-vivo studies.

Zoonotic cutaneous leishmaniasis (ZCL) is widely distributed in Iran and around the world. Also, Khuzestan Province is an endemic focus of ZCL. This study aims to investigate the natural infection of sand flies with the Leish-mania parasite in Karun County.

Sand flies were collected from Jangiyeh, Qaleh Chanan, Kut-e-Navaser, and Ghazavieh in the spring and summer in the year of 2019, by installing 60 sticky paper traps each time (30 traps outdoors and 30 traps indoors). Two hundred female sand flies with different abdominal conditions (empty, blood-fed, semi-gravid, and gravid) were exam-ined for infection rate using the Nested-PCR method.

In this study, seven species of sand flies including Phlebotomus papatasi, Ph. alexandri, Ph. sergenti, Ph. cau-casicus, Sergentomyia tiberiadis, Se. sintoni, and Se. antennata were reported from Karun County, with a frequency of 79.64%, 16.96%, 1.07%, 0.18%, 0.36%, 1.61%, and 0.18%, respectively. Only eleven specimens of Ph. papatasi were found to be positive for Leishmania major, with an overall infection rate of 7.8%. The infection of Ph. papatasi was specifically reported in blood-fed, gravid, and semi-gravid specimens, with infection rates of 17.02%, 4.35%, and 14.29%, respectively.

In this study, the infection of L. major from Ph. papatasi was reported. The results can be used in planning the control of ZCL in the study area.

Stem cell-derived secretome (SE) released into the extracellular space contributes to tissue repair. The present study aimed to investigate the impact of isolated secretome (SE) from adipose-derived mesenchymal stem cells (ASCs) on Leishmania major (L. major) lesions in BALB/c mice. 

This experimental study was conducted at Ahvaz University of Medical Sciences (Ahvaz, Iran) in 2021. Forty female BALB/c mice were infected with stationary phase promastigotes through intradermal injection in the bottom of their tail and randomly divided into four groups (n=10 per group). The mice were given SE (20 mg/mL), either alone or in combination with Glucantime (GC, 20 mg/mL/Kg), meglumine antimoniate (20 mg/mL/Kg) for the GC group, and phosphate-buffered saline (PBS) for the control group. After eight weeks, the lesion size, histopathology, the levels of Interleukin 10 (IL-10), and Interleukin 12 (IL-12) were assessed. For the comparison of values between groups, the parametric one-way ANOVA was used to assess statistical significance.

At the end of the experiment, the mice that received SE had smaller lesions (4.56±0.83 mm versus 3.62±0.59 mm, P=0.092), lower levels of IL-10 (66.5±9.7 pg/mL versus 285.4±25.2 pg/mL, P<0.001), and higher levels of IL-12 (152.2±14.2 pg/mL versus 24.2±4.4 pg/mL, P<0.001) than the control. Histopathology findings revealed that mice treated with SE had a lower parasite burden in lesions and spleen than the control group. 

The current study demonstrated that ADSC-derived SE could protect mice infected with L. major against leishmaniasis.

We aimed to verify the susceptibility of Leishmania infantum, L. major and L. tropica, to commercial lectins in order to identify the three Leishmania species.

The degree of agglutination was determined both macroscopically and microscopically and was scored negative (-) to positive (from 1+- 4+) based on their percentage of agglutination.

Jacalin and UEA-1 were capable of agglutination of L. infantum isolates in both logarithmic and stationary phases at a concentration of 1000 μg/ml (100%). L. tropica isolates showed agglutination with the lectin UEA-1 in both logarithmic and stationary phases (62.5% and 87.5%). L. major and L. tropica showed 75% agglutination with lectin Jacalin in both logarithmic and stationary phases. L. tropica isolates showed 25% agglutination with the lectin WGA in the logarithmic phase. L. infantum, L. major and L. tropica isolates showed 25, 12.5 and 37.5% agglutination in the stationary phase, however, did not show agglutination in logarithmic phases. L. major isolates showed 12.5% agglutination with the lectin PHA in the stationary phase, however, were incapable of agglutination with the L. tropica and L. infantum in both logarithmic and stationary phases.

Despite the fact, that JCA and I-UEA lectins were not able to completely separate L. infantum, L. major and L. tropica. WGA lectin and PHA lectin can help in separating the species of Leishmania parasites.

Leishmania is the parasitic protozoan responsible for leishmaniases, a disease that can cause a range of cutaneous, mucosal, and visceral infections. Two subgenera L. Viannia and L. Leishmania are known to infect humans in the tropics and subtropics of the Americas. The aim of the present study was to develop a new pair of primers for the two subgenera and test in clinical samples.

We designed two new pairs of primers for a PCR method from two conserved genes, cysteine proteinase B (cpb) and N-acetylglucosamine-6-phosfate deacetylase-like protein (nagA), as specific markers for those two respective subgenera. Primers were tested with 16 microscopical positive clinical samples from the Amazon region of Ecuador obtained in 2010-2020 period.

The cpb presented a band of 172 bp and the nagA a band of 300 bp, thus clearly differentiating L. viannia from L. leishmania. Additionally, primers identified and differentiated the clinical samples in the two subgenera.

The new primers targeting different two genes and standardized in a PCR assay could identified and differentiated Leishmania parasites at subgenus level. This protocol could be used for Leishmania genus identification and diagnosis at the subgenus level and for determining the parasite's geographical distribution where different Leishmania subgenera are found in the same area.

Epidemiological studies, classification and genetic studies of Leishmania species are effective in treatment, control and prevention in endemic areas. We aimed to investigate the genetic diversity and phylogeny of Leishmania in Zoonotic foci located in northeastern Iran using nagt gene for the first time.

DNA of 100 confirmed positive slides collected from the health centers of Sarkhes, Darghez, Fariman, Esfarayen, and Sabzevar were extracted during 2020-2021. The partial sequence of kDNA was amplified to identify the species. Twenty-five DNA samples were randomly subjected to amplify by nagt gene primes and were sequenced. The sequences were aligned with reference sequences in National Center for Biotechnology Information (NCBI). Then, the genetic similarities of the sequences were checked using Clustalx2.1 software and the phylogenetic tree was drawn by Mega 7 software.

All the positive samples were diagnosed as L. major. Approximately, half of the sequences of species were similar to two reference genes JX103550.1:404-712 L. major Esfahan and KX759012.1:568-807 L. Major Ilam (more than 90% similarity). According to the results of the phylogeny tree, the closest genotype to our study samples was JX103550.1:404-712 L. major Esfahan.

The most causative agent CL in these areas was L. major. The genetic diversity of L. major was high such as other zoonotic foci in Iran. Due to the high similarity of the strains in the study areas with the strains of Isfahan and Ilam, similar control and prevention methods is suggested in these areas.

Cutaneous leishmaniasis (CL) frequently occurs in many rural and urban areas of Iran. Leishmania major and L. tropica are principally two causative agents of CL in Iran. We report here a case of leishmaniasis of the ear in a 61-year-old man referred to the Reference laboratory, Kashan, central Iran, in Jan 2022. He suffered from a 2-month history of a 1×3 cm lesion on the left ear. In the microscopy examination, amastigotes forms of Leishmania spp. were observed. L. tropica was confirmed using a single PCR with species-specific primers. The patient was introduced to a physician to begin the treatment protocol. It is recommended that physicians, especially in an endemic area, investigate any atypical lesion for CL.

Leishmaniases are a group of vector-borne parasitic diseases transmitted through the infected sand flies. Leishmania parasites are inoculated into the host skin along with sand fly saliva. The sand fly saliva consists of biologically active molecules with anticoagulant, anti-inflammatory, and immunomodulatory properties. Such properties help the parasite circumvent the host's immune responses. The salivary compounds support the survival and multiplication of the parasite and facilitate the disease progression. It is documented that frequent exposure to uninfected sand fly bites produces neutralizing antibodies against specific salivary proteins and further activates the cellular mechanisms to prevent the establishment of the disease. The immune responses due to sand fly saliva are highly specific and depend on the composition of the salivary molecules. Hence, thorough knowledge of these compounds in different sand fly species and information about their antigenicity are paramount to designing an effective vaccine. Herein, we review the composition of the sand fly saliva, immunomodulatory properties of some of its components, immune responses to its proteins, and potential vaccine candidates against leishmaniases.

 Leishmaniasis is among the seven more significant tropical diseases, and it is a major global health issue with a wide range of clinical symptoms and potentially lethal consequences. Resveratrol and its derivatives have been shown to have anti-Leishmanial properties. This study aimed to use a meta-analysis of relevant papers to determine the leishmanicidal impact of resveratrol and its derivatives.

 A comprehensive search method was used to query the electronic databases of PubMed, ScienceDirect, Embase, ISI Web of Science, and Scopus up until June 2021. The articles that met the inclusion criteria were chosen. Random-effects models were used to calculate mean differences in IC50 (concentration corresponding to a 50% reduction in Leishmania) for each outcome. The Newcastle-Ottawa Scale was used to assess the quality of the evidence. To assess heterogeneity and the stability of the pooled data, sensitivity and subgroup analyses were performed. The Egger's and Begg's tests were used to assess publication bias.

 In the meta-analysis, nine studies were considered. Resveratrol (RSV) and its derivatives significantly reduced survivability in Leishmania promastigote [24.02 mg/ml; (95% CI 17.1, 30.8); P<0.05; I2 = 99.8%; P Heterogeneity = 0.00] and amastigote [18.3 mg/ml; (95% CI 13.5, 23.2); P<0.05; I2 = 99.6%; P Heterogeneity= 0.00]. The meta-analysis revealed a considerable publication bias. Sensitivity analyses revealed that the effect magnitude was similar, but the heterogeneity was reduced. According to subgroup analysis, the pooled effect sizes of leishmanicidal resveratrol and its derivatives were altered by the kind of stilbenes and Leishmania species.

 According to the findings of this meta-analysis, RSV and its derivatives could be a possible therapeutic option for leishmaniasis. However, more research is needed to confirm and employ this chemical against Leishmania.

Leishmania is a eukaryotic protozoan parasite belonging to the Trypanosomatidae family. The Iranian Lizard Leishmania (I.L.L.), which is non-pathogenic to mammals, shows great promise to be used as an expression system for recombinant protein production. Unlike other Leishmania strains, the ideal culture medium for I.L.L. has not been established, although it is commonly cultured in the RPMI1640 medium.

We investigated the growth rate of the wild and recombinant I.L.L. in BHI, RPMI1640, LB, and M199 media with and without FBS, hemin, or lyophilized rabbit serum. Subsequently, the expression rate of the recombinant protein in these media was compared.

The growth rate of I.L.L. in RPMI1640 medium and LB broth was similar and supplementation with 10% FBS did not affect the growth rate. The amount of protein expression in the LB medium was higher than in the other three media.

The LB broth is an appropriate medium for I.L.L. culture and recombinant protein production.

Cutaneous leishmaniasis (CL) is a chronic granulomatous dermatitis (CGD). Approximately, 90% of CL patients are from seven countries including Iran. We explain polymerase chain reaction (PCR) diagnostic technique for chronic granulomatosis dermatoses including CL in Mashhad, Iran.

This study enrolled 64 patients within 2009-2013 with chronic granulomatosis dermatitis referred to dermatology and pathology departments of Imam Reza Hospital, affiliated to Mashhad University of Medical Sciences (MUMS), Mashhad, Iran. We gathered demographic data from archived folders. Histological light microscopic evaluation and parasitological tests were done on selected specimens. We used PCR diagnostic test on specimens. Statistical analysis was done by SPSS version 15.

Generally, 7 out of 64 specimens had Leishmania DNA and other samples had no Leishmania DNA. The mean age of patients was 46 ± 18.77 years; disease duration was 7 ± 6.73 months ranging from 1-24 months. Most of the lesions were located on face and upper limb. Totally, 5 out of 7 samples were Leishmania major and 2 out of 7 samples were L. tropica. Tuberculoid granuloma was present in L. tropica samples and 3 of L. major samples. Other light microscopic changes were as follow: 42 suppurative granuloma, and epidermal changes including atrophy, pseudoepitheliomatous hyperplasia, and parakeratosis with dermal changes including, plasma cell, involvement of papillary and reticular dermis, and distribution of granuloma to hypodermis.

Our results addressed PCR-based diagnosis of chronic cutaneous leishmaniasis, which is resulted from L. major and L. tropica.

This study was designed considering the challenges of leishmaniasis treatment and the benefits of carriers of drug delivery systems to review plant bioactive ingredients in delivery systems and nanocarriers for the treatment of leishmaniasis.

The methodology of this review investigation followed the 06-PRISMA recommendations. The searches were carried out up to January 30, 2022, in the central English databases SCOPUS, WEB OF SCIENCE, EMBASE, PUBMED, and GOOGLE SCHOLAR using the search terms “ç”, “leishmaniasis”, “herbal medicines”, “drug delivery”, “nanocarriers”, “herbal compounds”, and “secondary metabolites”.

Out of 5731 articles, 19 publications, including 12 in vivo (63.15%), 3 in vitro (15.8%), and 4 in vitro/ in vivo (21.1%) up to 2022, fulfilled the criteria presence for argument in the current systematic study. Plant bioactive ingredients were curcumin, betulinic acid, artemisinin, 4-nitrobenzaldehyde thiosemicarbazone, andrographolide, pentalinonsterol, ursolic acid, amarogentin, carvacrol, 14-deoxy-11-oxo-andrographolide, quercetin, beta-lapachone, cedrol, 2ˊ,6ˊ-dihydroxy-4ˊ-methoxychalcone, and oleanolic acid.

The high potential of plant bioactive ingredients in delivery systems due to the load on the nanocarrier for the treatment of leishmaniasis through some main mechanisms of action, e.g. changes in the fluidity and the structure of the cell wall, creation of reactive oxygen species (ROS) and mitochondrial dysfunction, inhibition of DNA topoisomerase I enzyme, minimal cytotoxicity, stimulation of cell cycle disruption, stimulation of apoptosis, enhancement of the immune system. However, further investigations, especially in the clinical setting, are required to confirm these findings.

Amastin is a surface glycoprotein in Leishmania species and one of the most important vaccine candidates due to its involvement in pathogenesis and being an essential virulence factor for parasite replication within the mammalian host cells. There are more than 60 copies of Amastin gene per genome of the parasite.

Following phylogenetic analysis, a selected Amastin sequence was optimized and cloned with signal peptide in Escherichia coli. The recombinant protein was evaluated by SDG-PAGE and a specific antibody by Western blotting.

Among the Amastin sequences within different chromosomes of Leishmania major, the main type known as delta Amastin (primary distributed on chromosome 34) could be expressed in E. coli host and was confirmed by SDG-PAGE and Western blotting.

Due to its copy number and evolutionary conservation and its role in pathogenesis, δ-Amastin is considered as an important vaccine candidate against leishmaniasis which could be expressed as a recombinant protein in E. coli.

Protein complexes are involved in many vital biological processes. Therefore, researchers need these protein complexes for biochemical and biophysical studies. Several methods exist for expressing multi-subunit proteins in eukaryotic cells, such as 2A sequences, IRES, or intein. Nevertheless, each of these elements has several disadvantages that limit their usage. In this article, we suggest a new system for expressing multi-subunit proteins, which have several advantages over existing methods meanwhile it, lacks most of their disadvantages. Leishmania is a unicellular eukaryote and member of the Trypanosomatidae family. In the expression system of Leishmania, pre-long RNAs that contain several protein sequences transcribe. Then these long RNAs separate into mature mRNAs in the process named trans splicing. For producing multi-subunit protein, Leishmania transformed with a vector containing the sequences of all subunits. Therefore, those subunits translate and form the complex under eukaryotic cell conditions. The sequence of each protein must separate by the spatial sequence needed for trans splicing. Based on a Leishmania expression pattern, not only is it possible to produce the complexes with the correct structures and post-translational modifications, but also it is possible to overcome previous method problems.

Cutaneous leishmaniasis (CL) is a self-curing skin infection distributed in tropics and subtropics. Up to one million cases of CL appeared in endemic areas a year. Leishmanization (artificially controlled infections) was widely used to control cutaneous leishmaniasis in the past. Basal cell carcinoma (BCC) is the most common epithelial neoplasm of the skin. Cases of BCC developing in a leishmanial scar have been documented. We present the first case of confirmed basal cell carcinoma arising in 2020 in an 81-old physician working in Moscow (Russian Federation) in a leishmanial scar.  It was 50 years after the primary lesion due to a successful leishmanization, widely used to control cutaneous leishmaniasis in the past.