Treatment with synthetic lipophilic tyrosyl ester controls Leishmania major infection by reducing parasite load in BALB/c mice

Parasitology ◽  
2016 ◽  
Vol 143 (12) ◽  
pp. 1615-1621 ◽  
Author(s):  
RABIAA M. SGHAIER ◽  
IMEN AISSA ◽  
HANÈNE ATTIA ◽  
AYMEN BALI ◽  
PABLO A. LEON MARTINEZ ◽  
...  

SUMMARYSynthesized lipophilic tyrosyl ester derivatives with increasing lipophilicity were effective against Leishmania (L.) major and Leishmania infantum species in vitro. These findings prompted us to test in vivo leishmanicidal properties of these molecules and their potential effect on the modulation of immune responses. The experimental BALB/c model of cutaneous leishmaniasis was used in this study. Mice were infected with L. major parasites and treated with three in vitro active tyrosyl esters derivatives.Among these tested tyrosylcaprate (TyC) compounds, only TyC10 exhibited an in vivo anti-leishmanial activity, when injected sub-cutaneously (s.c.). TyC10 treatment of L. major-infected BALB/c mice resulted in a decrease of lesion development and parasite load. TyC10 s.c. treatment of non-infected mice induced an imbalance in interferon γ/interleukin 4 (IFN-γ/IL-4) ratio cytokines towards a Th1 response. Our results indicate that TyC10 s.c. treatment improves lesions’ healing and parasite clearance and may act on the cytokine balance towards a Th1 protective response by decreasing IL-4 and increasing IFN-γ transcripts. TyC10 is worthy of further investigation to uncover its mechanism of action that could lead to consider this molecule as a potential drug candidate.

2020 ◽  
Vol 477 (10) ◽  
pp. 2007-2026
Author(s):  
Ritika Kabra ◽  
Prajakta Ingale ◽  
Shailza Singh

The emergence of drug resistance is a major concern for combating against Cutaneous Leishmaniasis, a neglected tropical disease affecting 98 countries including India. Miltefosine is the only oral drug available for the disease and Miltefosine transporter proteins play a pivotal role in the emergence of drug-resistant Leishmania major. The cause of resistance is less accumulation of drug inside the parasite either by less uptake of the drug due to a decrease in the activity of P4ATPase–CDC50 complex or by increased efflux of the drug by P-glycoprotein (P-gp, an ABC transporter). In this paper, we are trying to allosterically modulate the behavior of resistant parasite (L. major) towards its sensitivity for the existing drug (Miltefosine, a phosphatidylcholine analog). We have used computational approaches to deal with the conservedness of the proteins and apparently its three-dimensional structure prediction through ab initio modeling. Long scale membrane-embedded molecular dynamics simulations were carried out to study the structural interaction and stability. Parasite-specific motifs of these proteins were identified based on the machine learning technique, against which a peptide library was designed. The protein–peptide docking shows good binding energy of peptides Pg5F, Pg8F and PC2 with specific binding to the motifs. These peptides were tested both in vitro and in vivo, where Pg5F in combination with PC2 showed 50–60% inhibition in resistant L. major's promastigote and amastigote forms and 80–90% decrease in parasite load in mice. We posit a model system wherein the data provide sufficient impetus for being novel therapeutics in order to counteract the drug resistance phenotype in Leishmania parasites.


2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Gordana Panic ◽  
Marie-Thérèse Ruf ◽  
Jennifer Keiser

ABSTRACT To date, there is only one drug in use, praziquantel, to treat more than 250 million people afflicted with schistosomiasis, a debilitating parasitic disease. The aryl hydantoin Ro 13-3978 is a promising drug candidate with in vivo activity superior to that of praziquantel against both adult and juvenile Schistosoma mansoni organisms. Given the drug's contrasting low activity in vitro and the timing of its onset of action in vivo, it was postulated that immune-assisted parasite clearance could contribute to the drug's in vivo activity. We undertook histopathological studies to investigate this hypothesis. Infected mice were treated with an effective dose of Ro 13-3978 (100 mg/kg of body weight) and were dissected before and after the drug's in vivo onset of action. The veins and livers were excised, paraffin-embedded, and sectioned, and macrophages (IBA-1), neutrophils (Neutro), B cells (CD45R), and T cells (CD3) were stained by immunohistochemistry. For comparison, samples from infected untreated mice and mice treated with effective doses of praziquantel (400 mg/kg), oxamniquine (200 mg/kg), and mefloquine (200 mg/kg) were examined. At 24 h after treatment with Ro 13-3978, significant macrophage recruitment to the veins was observed, along with a modest increase in circulating B cells, and at 48 h, neutrophils and T cells are also present. Treatment with praziquantel and oxamniquine showed similar patterns of recruitment but with comparatively higher cellular levels, whereas mefloquine treatment resulted in minimal cell recruitment until 3 days posttreatment. Our study sheds light on the immediate immune responses to antischistosomal treatment in mice and provides further insight into immune effector mechanisms of schistosome clearance.


1997 ◽  
Vol 185 (12) ◽  
pp. 2101-2110 ◽  
Author(s):  
Amy Hagenbaugh ◽  
Sherven Sharma ◽  
Steven M. Dubinett ◽  
Sherry H.-Y. Wei ◽  
Richard Aranda ◽  
...  

Interleukin (IL)-10 is a pleiotropic cytokine which inhibits a broad array of immune parameters including T helper cell type 1 (Th1) cytokine production, antigen presentation, and antigenspecific T cell proliferation. To understand the consequences of altered expression of IL-10 in immune models of autoimmune disease, the response to infectious agents, and the response to tumors, we developed transgenic mice expressing IL-10 under the control of the IL-2 promoter. Upon in vitro stimulation, spleen cells from unimmunized transgenic mice secrete higher levels of IL-10 and lower amounts of IFN-γ than do controls, although no gross abnormalities were detected in lymphocyte populations or serum Ig levels. Transfer of normally pathogenic CD4+ CD45RBhigh splenic T cells from IL-10 transgenic mice did not cause colitis in recipient severe combined immunodeficiency mice. Furthermore, co-transfer of these transgenic cells with CD4+ CD45RBhigh T cells from control mice prevented disease. Transgenic mice retained their resistance to Leishmania major infection, indicating that their cell-mediated immune responses were not globally suppressed. Lastly, in comparison to controls, IL-10 transgenic mice were unable to limit the growth of immunogenic tumors. Administration of blocking IL-10 mAbs restored in vivo antitumor responses in the transgenic mice. These results demonstrate that a single alteration in the T cell cytokine profile can lead to dramatic changes in immune responses in a manner that is stimulus dependent. These mice will be useful in defining differences in inflammatory conditions and cellular immunity mediated by IL-10.


Parasitology ◽  
2018 ◽  
Vol 146 (3) ◽  
pp. 322-332 ◽  
Author(s):  
Gerusa B. Carvalho ◽  
Lourena E. Costa ◽  
Daniela P. Lage ◽  
Fernanda F. Ramos ◽  
Thaís T. O. Santos ◽  
...  

AbstractIn the current study, phage-exposed mimotopes as targets against tegumentary leishmaniasis (TL) were selected by means of bio-panning cycles employing sera of TL patients and healthy subjects, besides the immune stimulation of peripheral blood mononuclear cells (PBMCs) collected from untreated and treated TL patients and healthy subjects. The clones were evaluated regarding their specific interferon-γ (IFN-γ) and interleukin-4 (IL-4) production in the in vitro cultures, and selectivity and specificity values were calculated, and those presenting the best results were selected for the in vivo experiments. Two clones, namely A4 and A8, were identified and used in immunization protocols from BALB/c mice to protect against Leishmania amazonensis infection. Results showed a polarized Th1 response generated after vaccination, being based on significantly higher levels of IFN-γ, IL-2, IL-12, tumour necrosis factor-α (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF); which were associated with lower production of specific IL-4, IL-10 and immunoglobulin G1 (IgG1) antibodies. Vaccinated mice presented significant reductions in the parasite load in the infected tissue and distinct organs, when compared with controls. In conclusion, we presented a strategy to identify new mimotopes able to induce Th1 response in PBMCs from TL patients and healthy subjects, and that were successfully used to protect against L. amazonensis infection.


2002 ◽  
Vol 70 (10) ◽  
pp. 5715-5720 ◽  
Author(s):  
Jian Li ◽  
Udaikumar M. Padigel ◽  
Phillip Scott ◽  
Jay P. Farrell

ABSTRACT Following infection of susceptible BALB/c mice with Leishmania major, early production of interleukin-4 (IL-4) is associated with the development of a nonprotective Th2 response and the development of progressive disease. Treatment of mice with IL-12 at the time of infection can promote the activation of a protective Th1 response; however, IL-12 treatment of mice with established infections has little effect on the progress of lesion development. This may be due to a down-regulation of the IL-12 receptor β2 chain (IL-12Rβ2) that accompanies the expansion of IL-4-producing Th2 cells. We have examined whether prostaglandins function to regulate in vivo responsiveness to IL-12. Mice treated with indomethacin are responsive to treatment with exogenous IL-12 through at least the first 2 weeks of infection and, unlike control mice treated with IL-12, develop an enhanced Th1-type response associated with increased enhanced resistance to infection. Cells from indomethacin-treated mice also exhibit enhanced production of gamma interferon (IFN-γ) following in vitro stimulation with IL-12. Although in vivo indomethacin treatment did not appear to influence IL-12 production in infected mice, cells from indomethacin-treated mice did express higher levels of IL-12Rβ2, suggesting that prostaglandins may play a role in the loss of IL-12 responsiveness observed during nonhealing L. major infections.


2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Maryam Iman ◽  
Zhaohua Huang ◽  
Seyedeh Hoda Alavizadeh ◽  
Francis C. Szoka ◽  
Mahmoud R. Jaafari

ABSTRACT 1,2-Distigmasterylhemisuccinoyl-sn-glycero-3-phosphocholine (DSHemsPC) is a new lipid in which two molecules of stigmasterol (an inexpensive plant sterol) are covalently linked via a succinic acid to glycerophosphocholine. Our previous study revealed that liposome (Lip)-intercalated amphotericin B (AMB) prepared from DSHemsPC (DSHemsPC-AMB-Lip) possesses excellent colloidal properties and in vitro antifungal and antileishmanial activities similar to those of the liposomal AMB preparation AmBisome. The aim of this study was to determine the biodistribution and evaluate the antileishmanial effects of DSHemsPC-AMB-Lip in Leishmania major-infected BALB/c mice. The serum profile and tissue concentrations of AMB were similar in DSHemsPC-AMB-Lip- and AmBisome-treated mice after intravenous (i.v.) injection. Multiple i.v. doses of the micellar formulation of AMB (Fungizone; 1 mg/kg of body weight), DSHemsPC-AMB-Lip (5 mg/kg), and AmBisome (5 mg/kg) were used in L. major-infected BALB/c mouse models of early and established lesions. In a model of the early lesions of cutaneous leishmaniasis (CL), the results indicated that the level of footpad inflammation was significantly (P < 0.001) lower in mice treated with DSHemsPC-AMB-Lip and AmBisome than mice treated with empty liposomes or 5% dextrose. The splenic and footpad parasite load was also significantly (P < 0.001) lower in these groups of mice than in control mice that received 5% DW or free liposome. The in vivo activity of DSHemsPC-AMB-Lip was comparable to that of AmBisome, and both provided improved results compared to those achieved with Fungizone at the designated doses. The results suggest that systemic DSHemsPC-AMB-Lip administration may be useful for the treatment of leishmaniasis, and because it costs less to produce DSHemsPC-AMB-Lip than AmBisome, DSHemsPC-AMB-Lip merits further investigation.


2021 ◽  
Vol 9 (10) ◽  
pp. 2113
Author(s):  
Aishah Albalawi

This experimental investigation was designed to assess the in vitro and in vivo antileishmanial effects of Z. spina-christi methanolic extract (ZSCME) and also aims to assess some of the antileishmanial mechanisms such as the NO production, apoptosis, and plasma membrane permeability. We assessed the in vitro leishmanicidal effects of ZSCME (10–200 µg/mL) against intracellular amastigote stage of the Leishmania major (MRHO/IR/75/ER) and, then, in vivo examined male BALB/c mice infected by L. major. In addition, the rate of infectivity, Caspase 3 activity, nitric oxide (NO) production, the plasma membrane permeability, and the cytotoxic effects of ZSCME were studied. The primary phytochemical analysis of ZSCME revealed the existence of high amounts of flavonoids, tannins, glycosides, alkaloids, and saponin in this plant. The findings exhibited that ZSCME meaningfully (p < 0.001) reduced the viability of amastigotes of L. major, whereas it prompted the creation and release of NO, apoptosis, and the plasma membrane permeability (p < 0.05) and indicated no cytotoxicity in macrophage cells. The in vivo results also demonstrated that ZSCME significantly decreased the parasite load and the diameter of the lesions in the infected mice. Our results demonstrate the promising in vitro and in vivo antileishmanial effects of ZSCME against of L. major. Although the findings of the present study showed some possible antileishmanial mechanisms of ZSCME, such as stimulating NO production, apoptosis, and increasing plasma membrane permeability, additional investigations are required to confirm these results.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Gert-Jan Wijnant ◽  
Katrien Van Bocxlaer ◽  
Vanessa Yardley ◽  
Sudaxshina Murdan ◽  
Simon L. Croft

ABSTRACT The 4-aminoquinoline chloroquine (CQ) is clinically used in combination with doxycycline to cure chronic Q fever, as it enhances the activity of the antibiotic against the causative bacterium Coxiella burnetii residing within macrophage phagolysosomes. As there is a similar cellular host-pathogen biology for Leishmania parasites, this study aimed to determine whether such an approach could also be the basis for a new, improved treatment for cutaneous leishmaniasis (CL). We have evaluated the in vitro and in vivo activities of combinations of CQ with the standard drugs paromomycin (PM), miltefosine, and amphotericin B against Leishmania major and Leishmania mexicana. In 72-h intracellular antileishmanial assays, outcomes were variable for different drugs. Significantly, the addition of 10 μM CQ to PM reduced 50% effective concentrations (EC50s) by over 5-fold against L. major and against normally insensitive L. mexicana parasites. In murine models of L. major and L. mexicana CL, daily coadministration of 50 mg/kg of body weight PM and 25 mg/kg CQ for 10 days resulted in a significant reduction in lesion size but not in parasite load compared to those for mice given the same doses of PM alone. Overall, our data indicate that PM-CQ combination therapy is unlikely to be a potential candidate for further preclinical development.


Author(s):  
Mostafa GHOLAMREZAEI ◽  
Soheila ROUHANI ◽  
Mehdi MOHEBALI ◽  
Samira MOHAMMADI-YEGANEH ◽  
Mostafa HAJI MOLLA HOSEINI ◽  
...  

Background: We aimed to investigate the effect of miR-15a mimic and inhibitor of miR-155 expression on apoptosis induction in macrophages infected with Iranian strain of Leishmania major in-vitro and in-vivo. Methods: RAW 264.7 cells were infected with L. major promastigotes (MRHO/IR/75/ER), and then were treated with miRNAs. For in-vivo experiment, BALB/c mice were inoculated with L. major promastigotes, and then they were treated with miRNAs. For evaluation of miRNA therapeutic effect, in-vitro and in-vivo studies were performed using quantitative Real-time PCR, Flow cytometry, lesion size measurement, and Limiting Dilution Assay (LDA). This study was performed in Shahid Beheshti University of Medical Sciences in 2019. Results: In-vitro results of flow cytometry showed that using miR-15a mimic, miR-155 inhibitor or both of them increased apoptosis of macrophages. In in-vivo, size of lesion increased during experiment in control groups (P<0.05) while application of both miR-155 inhibitor and miR-15a mimic inhibited the increase in the size of lesions within 6 wk of experiment (P=0.85). LDA results showed that microRNA therapy could significantly decrease parasite load in mimic or inhibitor receiving groups compared to the control group (P<0.05). Conclusion: miR-155 inhibitor and miR-15a mimic in L. major infected macrophages can induce apoptosis and reduce parasite burden. Therefore, miRNA-based therapy can be proposed as new treatment for cutaneous leishmaniasis.


2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Felipe Rodriguez ◽  
Sarah F. John ◽  
Eva Iniguez ◽  
Sebastian Montalvo ◽  
Karina Michael ◽  
...  

ABSTRACT Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL, and current drug regimens present several drawbacks, such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase 1 of L. major (MetAP1Lm), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activities of eight novel MetAP1 inhibitors (OJT001 to OJT008) were investigated. Three compounds, OJT006, OJT007, and OJT008, demonstrated potent antiproliferative effects in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect in transgenic L. major promastigotes overexpressing MetAP1Lm was diminished by almost 10-fold in comparison to the effect in wild-type promastigotes. Furthermore, the in vivo activities of OJT006, OJT007, and OJT008 were investigated in L. major-infected BALB/c mice. In comparison to the footpad parasite load in the control group, OJT008 decreased the footpad parasite load significantly, by 86%, and exhibited no toxicity in treated mice. We propose MetAP1 inhibitor OJT008 as a potential chemotherapeutic candidate against CL infection caused by L. major infection.


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