scholarly journals Antileishmanial Effects of Synthetic EhPIb Analogs Derived from the Entamoeba histolytica Lipopeptidephosphoglycan

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Helena Fehling ◽  
Siew Ling Choy ◽  
Frederic Ting ◽  
Dirk Landschulze ◽  
Hannah Bernin ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Entamoeba Histolytica ◽  
Murine Model ◽  
Leishmania Major ◽  
Interleukin 4 ◽  
Intestinal Protozoan ◽  
Cutaneous Lesions ◽  
Content Type ◽  
Arginase 1

ABSTRACT With an estimated number of new cases annually of approximately 1.4 million, leishmaniasis belongs to the most important parasitic diseases in the world. Nevertheless, existing drugs against leishmaniasis in general have several drawbacks that urgently necessitate new drug development. A glycolipid molecule of the intestinal protozoan parasite Entamoeba histolytica and its synthetic analogs previously showed considerable immunotherapeutic effects against Leishmania major infection. Here, we designed and synthesized a series of new immunostimulatory compounds derived from the phosphatidylinositol b anchor of Entamoeba histolytica (EhPIb) subunit of the native compound and investigated their antileishmanial activity in vitro and in vivo in a murine model of cutaneous leishmaniasis. The new synthetic EhPIb analogs showed almost no toxicity in vitro. Treatment with the analogs significantly decreased the parasite load in murine and human macrophages in vitro. In addition, topical application of the EhPIb analog Eh-1 significantly reduced cutaneous lesions in the murine model, correlating with an increase in the production of selected Th1 cytokines. In addition, we could show in in vitro experiments that treatment with Eh-1 led to a decrease in mRNA expression of arginase-1 (Arg1) and interleukin 4 (IL-4), which are required by the parasites to circumvent their elimination by the immune response. The use of the host-targeting synthetic EhPIb compounds, either alone or in combination therapy with antiparasitic drugs, shows promise for treating cutaneous leishmaniasis and therefore might improve the current unsatisfactory status of chemotherapy against this infectious disease.

scholarly journals Zinc(II)-Dipicolylamine Coordination Complexes as Targeting and Chemotherapeutic Agents for Leishmania major

2016 ◽  
Vol 60 (5) ◽  
pp. 2932-2940 ◽  
Author(s):  
Douglas R. Rice ◽  
Paola Vacchina ◽  
Brianna Norris-Mullins ◽  
Miguel A. Morales ◽  
Bradley D. Smith
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Mammalian Cells ◽  
Leishmania Major ◽  
Parasite Burden ◽  
Coordination Complexes ◽  
Chemotherapeutic Agents ◽  
Selective Toxicity ◽  
Content Type

ABSTRACTCutaneous leishmaniasis is a neglected tropical disease that causes painful lesions and severe disfigurement. Modern treatment relies on a few chemotherapeutics with serious limitations, and there is a need for more effective alternatives. This study describes the selective targeting of zinc(II)-dipicolylamine (ZnDPA) coordination complexes towardLeishmania major, one of the species responsible for cutaneous leishmaniasis. Fluorescence microscopy ofL. majorpromastigotes treated with a fluorescently labeled ZnDPA probe indicated rapid accumulation of the probe within the axenic promastigote cytosol. The antileishmanial activities of eight ZnDPA complexes were measured using anin vitroassay. All tested complexes exhibited selective toxicity againstL. majoraxenic promastigotes, with 50% effective concentration values in the range of 12.7 to 0.3 μM. Similar toxicity was observed against intracellular amastigotes, but there was almost no effect on the viability of mammalian cells, including mouse peritoneal macrophages.In vivotreatment efficacy studies used fluorescence imaging to noninvasively monitor changes in the red fluorescence produced by an infection of mCherry-L. majorin a mouse model. A ZnDPA treatment regimen reduced the parasite burden nearly as well as the reference care agent, potassium antimony(III) tartrate, and with less necrosis in the local host tissue. The results demonstrate that ZnDPA coordination complexes are a promising new class of antileishmanial agents with potential for clinical translation.

scholarly journals Transgenic Expression of CXCR3 on T Cells Enhances Susceptibility to Cutaneous Leishmania major Infection by Inhibiting Monocyte Maturation and Promoting a Th2 Response

2014 ◽  
Vol 83 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Steve Oghumu ◽  
James C. Stock ◽  
Sanjay Varikuti ◽  
Ran Dong ◽  
Cesar Terrazas ◽  
...  
Keyword(s):  
T Cells ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Critical Role ◽  
Sand Fly ◽  
Interleukin 4 ◽  
Th2 Response ◽  
Content Type ◽  
Transgenic Expression ◽  
Inflammatory Monocytes

Cutaneous leishmaniasis, caused mainly byLeishmania major, an obligate intracellular parasite, is a disfiguring disease characterized by large skin lesions and is transmitted by a sand fly vector. We previously showed that the chemokine receptor CXCR3 plays a critical role in mediating resistance to cutaneous leishmaniasis caused byLeishmania major. Furthermore, T cells fromL. major-susceptible BALB/c but notL. major-resistant C57BL/6 mice fail to efficiently upregulate CXCR3 upon activation. We therefore examined whether transgenic expression of CXCR3 on T cells would enhance resistance toL. majorinfection in susceptible BALB/c mice. We generated BALB/c and C57BL/6 transgenic mice, which constitutively overexpressed CXCR3 under a CD2 promoter, and then examined the outcomes withL. majorinfection. Contrary to our hypothesis, transgenic expression of CXCR3 (CXCR3Tg) on T cells of BALB/c mice resulted in increased lesion sizes and parasite burdens compared to wild-type (WT) littermates afterL. majorinfection. Restimulated lymph node cells fromL. major-infected BALB/c-CXCR3Tgmice produced more interleukin-4 (IL-4) and IL-10 and less gamma interferon (IFN-γ). Cells in draining lymph nodes from BALB/c-CXCR3Tgmice showed enhanced Th2 and reduced Th1 cell accumulation associated with increased neutrophils and inflammatory monocytes. However, monocytes displayed an immature phenotype which correlated with increased parasite burdens. Interestingly, transgenic expression of CXCR3 on T cells did not impact the outcome ofL. majorinfection in C57BL/6 mice, which mounted a predominantly Th1 response and spontaneously resolved their infection similar to WT littermates. Our findings demonstrate that transgenic expression of CXCR3 on T cells increases susceptibility of BALB/c mice toL. major.

scholarly journals Deletion of Interleukin-4 Receptor Alpha-Responsive Keratinocytes in BALB/c Mice Does Not Alter Susceptibility to Cutaneous Leishmaniasis

2018 ◽  
Vol 86 (12) ◽  
Author(s):  
Melissa Govender ◽  
Ramona Hurdayal ◽  
Berenice Martinez-Salazar ◽  
Kaya Gqada ◽  
Shandre Pillay ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Parasite Burden ◽  
Interleukin 4 ◽  
High Dose ◽  
Littermate Control ◽  
Content Type ◽  
Receptor Alpha ◽  
Th2 Immune Response

ABSTRACTThe skin microenvironment at the site of infection plays a role in the early events that determine protective T helper 1/type 1 immune responses during cutaneous leishmaniasis (CL) infection. During CL in nonhealing BALB/c mice, early interleukin-4 (IL-4) can instruct dendritic cells for protective Th1 immunity. Additionally, keratinocytes, which are the principal cell type in the skin epidermis, have been shown to secrete IL-4 early afterLeishmania majorinfection. Here, we investigated whether IL-4/IL-13 signaling via the common IL-4 receptor alpha chain (IL-4Rα) on keratinocytes contributes to susceptibility during experimental CL. To address this, keratinocyte-specific IL-4Rα-deficient (KRT14creIL-4Rα−/lox) mice on a BALB/c genetic background were generated by gene targeting and site-specific recombination (Cre/loxP) under the control of the keratinocyte-specifickrt14locus. Following high-dose infection withL. majorIL-81 and LV39 promastigotes subcutaneously in the footpad, footpad swelling, parasite burden, IFN-γ/IL-4/IL-13 cytokine production, and type 1 and type 2 antibody responses were similar between KRT14creIL-4Rα−/loxand littermate control IL-4Rα−/loxBALB/c mice. An intradermal infection with low-doseL. majorIL-81 and LV39 promastigotes in the ear showed results in infected KRT14creIL-4Rα−/loxBALB/c mice similar to those of littermate control IL-4Rα−/loxBALB/c mice, with the exception of a significant decrease observed in parasite burden only at the site of LV39 infection in the ear. Collectively, our results show that autocrine and paracrine signaling of IL-4/IL-13 through the IL-4Rα chain on keratinocytes does not influence the establishment of a nonhealing Th2 immune response in BALB/c mice duringL. majorinfection.

scholarly journals Development of anEx VivoLymph Node Explant Model for Identification of Novel Molecules Active against Leishmania major

2013 ◽  
Vol 58 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Alex G. Peniche ◽  
Yaneth Osorio ◽  
Adam R. Renslo ◽  
Doug E. Frantz ◽  
Peter C. Melby ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Drug Efficacy ◽  
Peritoneal Macrophages ◽  
Effective Concentration ◽  
Content Type ◽  
Drug Candidates ◽  
New Drug ◽  
Vector Borne

ABSTRACTLeishmaniasis is a vector-borne zoonotic infection affecting people in tropical and subtropical regions of the world. Current treatments for cutaneous leishmaniasis are difficult to administer, toxic, expensive, and limited in effectiveness and availability. Here we describe the development and application of a medium-throughput screening approach to identify new drug candidates for cutaneous leishmaniasis using anex vivolymph nodeexplantculture (ELEC) derived from the draining lymph nodes ofLeishmania major-infected mice. The ELEC supported intracellular amastigote proliferation and contained lymph node cell populations (and their secreted products) that enabled the testing of compounds within a system that mimicked the immunopathological environment of the infected host, which is known to profoundly influence parasite replication, killing, and drug efficacy. The activity of known antileishmanial drugs in the ELEC system was similar to the activity measured in peritoneal macrophages infectedin vitrowithL. major. Using the ELEC system, we screened a collection of 334 compounds, some of which we had demonstrated previously to be active againstL. donovani, and identified 119 hits, 85% of which were confirmed to be active by determination of the 50% effective concentration (EC50). We found 24 compounds (7%) that had aninvitrotherapeuticindex (IVTI; 50% cytotoxic/effective concentration [CC50]/EC50) > 100; 19 of the compounds had an EC50below 1 μM. According to PubChem searchs, 17 of those compounds had not previously been reported to be active againstLeishmania. We expect that this novel method will help to accelerate discovery of new drug candidates for treatment of cutaneous leishmaniasis.

scholarly journals Efficacy of Paromomycin-Chloroquine Combination Therapy in Experimental Cutaneous Leishmaniasis

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Gert-Jan Wijnant ◽  
Katrien Van Bocxlaer ◽  
Vanessa Yardley ◽  
Sudaxshina Murdan ◽  
Simon L. Croft
Keyword(s):  
Combination Therapy ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Q Fever ◽  
Parasite Load ◽  
Potential Candidate ◽  
Preclinical Development ◽  
Content Type

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.

Ex vivoevidence for PGE2and LTB4involvement in cutaneous leishmaniasis: relation with infection status and cytokine production

Parasitology ◽  
1996 ◽  
Vol 112 (1) ◽  
pp. 13-19 ◽  
Author(s):  
S. Milano ◽  
F. Arcoleo ◽  
M. Dieli ◽  
R. D'agostino ◽  
G. De Nucci ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Ex Vivo ◽  
Early Stage ◽  
Inflammatory Cells ◽  
Interferon Γ ◽  
Interleukin 4 ◽  
Prostaglandin E ◽  
Ifn Γ

SUMMARYEx vivoculture of spleen cells from BALB/c mice infected with 2 × 106Leishmania major(L.major) promastigotes were cultured with ConcanavalinA (ConA) or leishmanial antigen (L. Ag) and tested for prostaglandin E2(PGE2) and for leukotriene B4(LTB4), in order to study their involvement in the evolution of cutaneous leishmaniasis and the connexion with lymphokine-mediated responses. The data were compared with those obtained in BALB/c mice protected againstL. majorby sublethal irradiation (550 rad; cured mice). In the unprotected BALB/c mice the levels of PGE2that were responsible for the depression of interferon-γ (IFN-γ) and tumour necrosis factor-α (TNFα) Th1-associated cytokines and for the relative increase in the interleukin-4 (IL-4) became higher and higher as the lesion progressed. On the contrary, the cured mice produced levels of PGE2similar to normal uninfected controls, high levels of TNFα and IFN-γ and low levels of IL-4. Elevated levels of LTB4were detected in the early stage of infection in the unprotected mice compared to cured ones, a sign of more intense inflammation and a stimulus for the recruitment of inflammatory cells. The observation that exogenous LTB4was able to enhance in vitro both Th1cytokines in cured mice and Th2cytokines in unprotected ones suggests that LTB4could act in the recruitment of the T cells already committed to Th1or Th2phenotype.

scholarly journals Topical Treatment for Cutaneous Leishmaniasis: Dermato-Pharmacokinetic Lead Optimization of Benzoxaboroles

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Katrien Van Bocxlaer ◽  
Eric Gaukel ◽  
Deirdre Hauser ◽  
Seong Hee Park ◽  
Sara Schock ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Skin Permeation ◽  
Mouse Skin ◽  
Topical Administration ◽  
Lesion Size ◽  
Drug Formulation ◽  
Content Type

ABSTRACTCutaneous leishmaniasis (CL) is caused by several species of the protozoan parasiteLeishmania, affecting an estimated 10 million people worldwide. Previously reported strategies for the development of topical CL treatments have focused primarily on drug permeation and formulation optimization as the means to increase treatment efficacy. Our approach aims to identify compounds with antileishmanial activity and properties consistent with topical administration. Of the test compounds, five benzoxaboroles showed potent activity (50% effective concentration [EC50] < 5 μM) against intracellular amastigotes of at least oneLeishmaniaspecies and acceptable activity (20 μM < EC50< 30 μM) against two more species. Benzoxaborole compounds were further prioritized on the basis of thein vitroevaluation of progression criteria related to skin permeation, such as the partition coefficient and solubility. An MDCKII-hMDR1 cell assay showed overall good permeability and no significant interaction with the P-glycoprotein transporter for all substrates except LSH002 and LSH031. The benzoxaboroles were degraded, to some extent, by skin enzymes but had stability superior to that ofpara-hydroxybenzoate compounds, which are known skin esterase substrates. Evaluation of permeation through reconstructed human epidermis showed LSH002 to be the most permeant, followed by LSH003 and LSH001. Skin disposition studies following finite drug formulation application to mouse skin demonstrated the highest permeation for LSH001, followed by LSH003 and LSH002, with a significantly larger amount of LSH001 than the other compounds being retained in skin. Finally, the efficacy of the leads (LSH001, LSH002, and LSH003) againstLeishmania majorwas testedin vivo. LSH001 suppressed lesion growth upon topical application, and LSH003 reduced the lesion size following oral administration.

scholarly journals Gallic and Ellagic Acids Are Promising Adjuvants to Conventional Amphotericin B for the Treatment of Cutaneous Leishmaniasis

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Michel Muálem de Moraes Alves ◽  
Daniel Dias Rufino Arcanjo ◽  
Kayo Alves Figueiredo ◽  
Jéssica Sara de Sousa Macêdo Oliveira ◽  
Felipe José Costa Viana ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Amphotericin B ◽  
Leishmania Major ◽  
Negative Control ◽  
Control Group ◽  
Histopathological Analysis ◽  
Activated Macrophages ◽  
Content Type

ABSTRACT In this study, we demonstrated the potential associative effect of combining conventional amphotericin B (Amph B) with gallic acid (GA) and with ellagic acid (EA) in topical formulations for the treatment of cutaneous leishmaniasis in BALB/c mice. Preliminary stability tests of the formulations and in vitro drug release studies with Amph B, GA, Amph B plus GA, EA, and Amph B plus EA were carried out, as well as assessment of the in vivo treatment of BALB/c mice infected with Leishmania major. After 40 days of infection, the animals were divided into 6 groups and treated twice a day for 21 days with a gel containing Amph B, GA, Amph B plus GA, EA, or Amph B plus EA, and the negative-control group was treated with the vehicle. In the animals that received treatment, there was reduction of the lesion size and reduction of the parasitic load. Histopathological analysis of the treatments with GA, EA, and combinations with Amph B showed circumscribed lesions with the presence of fibroblasts, granulation tissue, and collagen deposition, as well as the presence of activated macrophages. The formulations containing GA and EA activated macrophages in all evaluated parameters, resulting in the activation of cells of the innate immune response, which can generate healing and protection. GA and EA produced an associative effect with Amph B, which makes them promising for use with conventional Amph B in the treatment of cutaneous leishmaniasis.

Evaluating the Effect of Cinnarizine on Promastigotes and Amastigotes forms of Leishmania major

2020 ◽  
Vol 20 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Lima Asgharpour Sarouey ◽  
Parvaneh Rahimi-Moghaddam ◽  
Fatemeh Tabatabaie ◽  
Khadijeh Khanaliha
Keyword(s):  
Flow Cytometry ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Major ◽  
Inhibitory Effect ◽  
Control Group ◽  
Secondary Infections ◽  
Ic50 Values ◽  
J774 Cells ◽  
Mtt Assays

: As an important global disease, cutaneous leishmaniasis is associated with complications such as secondary infections and atrophic scars. The first line treatment with antimonials is expensive and reported to have serious side effects and enhance resistance development. The main objective of this study was to evaluate the effect of Cinnarizine on standard strains of Leishmania major because of paucity of information on this subject. Methods: In this experimental study, four concentrations of the drug (5, 10, 15 and 20 μg/ml) were added to Leishmania major cultures at 24, 48 and 72 hours intervals. MTT assays were performed to determine parasite viability and drug toxicity. Leishmania major promastigotes were augmented to the in vitro cultured macrophages (J774 cells) and then incubated for 72 hours. Half maximal inhibitory concentration (IC50) was ascertained by counting parasites. The inhibitory effect of the drug was compared with that of Glucantime. Flow-cytometry was performed to investigate apoptosis. Each test was repeated thrice. Results: The IC50 values of Cinnarizine after 72 hours were calculated to be 34.76 μg/ml and 23.73 μg/ml for promastigotes and amastigotes, respectively. The results of MTT assays showed 48 % promastigote viability after 72 hour-exposure to Cinnarizine at 20 μg/ml concentration. Programmed cell death in promastigote- and amastigote-infected macrophages was quantified to be 13.66 % and 98.7 %, respectively. Flow- cytometry analysis indicated that Cinnarizine induced early and late apoptosis in parasites. All treatments produced results which differed significantly from control group (P<0.05). Conclusion: Cinnarizine showed low toxicity with anti-leishmanial and apoptosis effects on both promastigote and intracellular amastigote forms. Therefore, we may suggest further assessment on animal models of this drug as candidates for cutaneous leishmaniasis therapy.

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