scholarly journals Vaccination with the Leishmania infantum Acidic Ribosomal P0 Protein plus CpG Oligodeoxynucleotides Induces Protection against Cutaneous Leishmaniasis in C57BL/6 Mice but Does Not Prevent Progressive Disease in BALB/c Mice

2005 ◽  
Vol 73 (9) ◽  
pp. 5842-5852 ◽  
Author(s):  
Salvador Iborra ◽  
Javier Carrión ◽  
Charles Anderson ◽  
Carlos Alonso ◽  
David Sacks ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Leishmania Infantum ◽  
Progressive Disease ◽  
Immunological Response ◽  
Parasite Load ◽  
Th2 Response ◽  
Suitable Alternative ◽  
Cpg Oligodeoxynucleotides ◽  
Potential Efficacy ◽  
Ifn Γ

ABSTRACT We have examined the efficacy of the administration in mice of a molecularly defined vaccine based on the Leishmania infantum acidic ribosomal protein P0 (rLiP0). Two different challenge models of murine cutaneous leishmaniasis were used: (i) subcutaneous inoculation of L. major parasites in susceptible BALB/c mice (a model widely used for vaccination analysis) and (ii) the intradermal inoculation of a low infective dose in resistant C57BL/6 mice (a model that more accurately reproduces the L. major infection in natural reservoirs and in human hosts). First, we demonstrated that C57BL/6 mice vaccinated with LiP0-DNA or rLiP0 protein plus CpG oligodeoxynucleotides (ODN) were protected against the development of dermal pathology and showed a reduction in the parasite load. This protection was associated with production of gamma interferon (IFN-γ) in the dermal site. Secondly, we showed that immunization with rLiP0 plus CpG ODN is able to induce only partial protection in BALB/c, since these mice finally developed a progressive disease. Further, we demonstrated that LiP0 vaccination induces a Th1 immunological response in both strains of mice. In both cases, the antibodies against LiP0 were predominantly of the immunoglobulin G2a isotype, which was correlated with an rLiP0-stimulated production of IFN-γ in draining lymph nodes. Finally, we demonstrated that LiP0 vaccination does not prevent the Th2 response induced by L. major infection in BALB/c mice. Taken together, these data indicate that the BALB/c model of cutaneous leishmaniasis may undervalue the potential efficacy of some vaccines based on defined proteins, making C57BL/6 a suitable alternative model to test vaccine candidates.

scholarly journals Parasite load, iNOS and cytokine profiles, and histopathological aspects of Leishmania infantum infection in dogs with different clinical presentations

2019 ◽  
Vol 49 (10) ◽  
Author(s):  
Tassia Cristina Bello de Vasconcelos ◽  
Sávio Freire Bruno ◽  
Luisa Helena Monteiro de Miranda ◽  
Fátima Conceição-Silva ◽  
Vinícius Silva Belo ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Clinical Symptoms ◽  
Immunological Response ◽  
Parasite Load ◽  
Hepatic Tissue ◽  
Inos Mrna ◽  
White Pulp ◽  
Clinical Presentations ◽  
Ifn Γ

ABSTRACT: Visceral leishmaniasis (VL) is a zoonotic disease with a canine urban reservoir in South America. Dogs from an endemic area within Brazil, which were naturally infected with Leishmania infantum, and those presenting severe clinical (SC), mild, or no clinical (MNC) disease, were evaluated. Parasite load, histopathology, and cytokine and iNOS mRNA expressions were assessed in the spleen and liver in order to determine the potential markers for disease susceptibility or resistance. As a result, dogs with both SC and MNC had high parasite loads; IFN-γ was the most expressive cytokine in both organs, along with IL-6 and IL-4 being detected in the spleen and liver, and IL-10 only in liver. The hepatic tissue presented higher medians for IFN-γ and IL-10, and was the main organ to produce cytokines with hepatic IL-10 suggesting a regulatory follow up. Granulomas were detected in both organs; however, when absent in spleen, they were associated with elevated IL-6 levels, thus highlighting the anti-inflammatory role of IL-6. Microscopic lesions in the spleen were predominantly characterized by an extensively disorganized white pulp and splenic response was suggested as sub optimized. Parasite load, tissue damage, and immunological response may vary in the dogs with similar clinical symptoms, which may not be a good parameter for assessing the animal’s susceptibility to VL.

scholarly journals The Leishmania infantum Acidic Ribosomal Protein P0 Administered as a DNA Vaccine Confers Protective Immunity to Leishmania major Infection in BALB/c Mice

2003 ◽  
Vol 71 (11) ◽  
pp. 6562-6572 ◽  
Author(s):  
Salvador Iborra ◽  
Manuel Soto ◽  
Javier Carrión ◽  
Ana Nieto ◽  
Edgar Fernández ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Leishmania Infantum ◽  
Leishmania Major ◽  
Parasite Burden ◽  
Immunological Response ◽  
Humoral Response ◽  
Ifn Γ ◽  
Immunogenic Properties ◽  
Ribosomal Protein P0 ◽  
Acidic Ribosomal Protein

ABSTRACT In this study, we examined the immunogenic properties of the Leishmania infantum acidic ribosomal protein P0 (LiP0) in the BALB/c mouse model. The humoral and cellular responses induced by the administration of the LiP0 antigen, either as soluble recombinant LiP0 (rLiP0) or as a plasmid DNA formulation (pcDNA3-LiP0), were determined. Also, the immunological response associated with a prime-boost strategy, consisting of immunization with pcDNA3-LiP0 followed by a boost with rLiP0, was assayed. Immunization with rLiP0 induced a predominant Th2-like humoral response, but no anti-LiP0 antibodies were induced after immunization with pcDNA3-LiP0, whereas a strong humoral response consisting of a mixed immunoglobulin G2a (IgG2a)-IgG1 isotype profile was induced in mice immunized with the prime-boost regime. For all three immunization protocols, rLiP0-stimulated production of gamma interferon (IFN-γ) in both splenocytes and lymph node cells from immunized mice was observed. However, it was only when mice were immunized with pcDNA3-LiP0 that noticeable protection against L. major infection was achieved, as determined by both lesion development and parasite burden. Immunization of mice with LiP0-DNA primes both CD4+ and CD8+ T cells, which, with the L. major challenge, were boosted to produce significant levels of IL-12-dependent, antigen-specific IFN-γ. Taken together, these data indicate that genetic vaccination with LiP0 induces protective immunological effector mechanisms, yet the immunological response elicited by LiP0 is not sufficient to keep the infection from progressing.

scholarly journals Expression of Regulatory T Cells in Jejunum, Colon, and Cervical and Mesenteric Lymph Nodes of Dogs Naturally Infected with Leishmania infantum

2014 ◽  
Vol 82 (9) ◽  
pp. 3704-3712 ◽  
Author(s):  
Maria M. Figueiredo ◽  
Beatriz Deoti ◽  
Izabela F. Amorim ◽  
Aldair J. W. Pinto ◽  
Andrea Moraes ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Lymph Nodes ◽  
Leishmania Infantum ◽  
Parasite Load ◽  
Mesenteric Lymph Nodes ◽  
Content Type ◽  
Mesenteric Lymph ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACTUsing flow cytometry, we evaluated the frequencies of CD4+and CD8+T cells and Foxp3+regulatory T cells (Tregs) in mononuclear cells in the jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected withLeishmania infantumand in uninfected controls. All infected dogs showed chronic lymphadenitis and enteritis. Despite persistent parasite loads, no erosion or ulcers were evident in the epithelial mucosa. The colon harbored more parasites than the jejunum. Frequencies of total CD4+, total Foxp3, and CD4+Foxp3+cells were higher in the jejunum than in the colon. Despite negative enzyme-linked immunosorbent assay (ELISA) serum results for cytokines, levels of interleukin-10 (IL-10), gamma interferon (IFN-γ), transforming growth factor beta (TGF-β), and tumor necrosis factor alpha (TNF-α) were higher in the jejunum than in the colon for infected dogs. However, IL-4 levels were higher in the colon than in the jejunum for infected dogs. There was no observed correlation between clinical signs and histopathological changes or immunological and parasitological findings in the gastrointestinal tract (GIT) of canines with visceral leishmaniasis. However, distinct segments of the GIT presented different immunological and parasitological responses. The jejunum showed a lower parasite load, with increased frequencies and expression of CD4, Foxp3, and CD8 receptors and IL-10, TGF-β, IFN-γ, and TNF-α cytokines. The colon showed a higher parasite load, with increasing expression of IL-4.Leishmania infantuminfection increased expression of CD4, Foxp3, IL-10, TGF-β, IFN-γ, and TNF-α and reduced CD8 and IL-4 expression in both the jejunum and the colon.

scholarly journals Immunologic Indicators of Clinical Progression during Canine Leishmania infantum Infection

2009 ◽  
Vol 17 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Paola M. Boggiatto ◽  
Amanda E. Ramer-Tait ◽  
Kyle Metz ◽  
Erin E. Kramer ◽  
Katherine Gibson-Corley ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Progressive Disease ◽  
The United States ◽  
Interleukin 10 ◽  
Clinical Disease ◽  
Immunological Parameters ◽  
Peripheral Blood Mononuclear ◽  
Dramatic Rise ◽  
Ifn Γ ◽  
First Time

ABSTRACT In both dogs and humans Leishmania infantum infection is more prevalent than disease, as infection often does not equate with clinical disease. Previous studies additively indicate that advanced clinical visceral leishmaniasis is characterized by increased production of anti-Leishmania antibodies, Leishmania-specific lymphoproliferative unresponsiveness, and decreased production of gamma interferon (IFN-γ) with a concomitant increase of interleukin-10 (IL-10). In order to differentiate infection versus progressive disease for better disease prognostication, we temporally evaluated humoral and cellular immunologic parameters of naturally infected dogs. The work presented here describes for the first time the temporal immune response to natural autochthonous L. infantum infection in foxhounds within the United States. Several key changes in immunological parameters should be considered when differentiating infection versus clinical disease, including a dramatic rise in IgG production, progressive increases in antigen-specific peripheral blood mononuclear cell proliferation, and IFN-γ production. Polysymptomatic disease is precluded by increased IL-10 production and consistent detection of parasite kinetoplast DNA in whole blood. This clinical presentation and the immuno-dysregulation mirror those observed in human patients, indicating that this animal model will be very useful for testing immunomodulatory anti-IL-10 and other therapies.

scholarly journals A cytokine network balance influences the fate of Leishmania (Viannia) braziliensis infection in a cutaneous leishmaniasis hamster model

2020 ◽  
Author(s):  
MB Paiva ◽  
RP Ribeiro-Romão ◽  
L Resende-Vieira ◽  
T Braga-Gomes ◽  
MP Oliveira ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cutaneous Leishmaniasis ◽  
Tissue Damage ◽  
Normal Skin ◽  
Late Phase ◽  
Parasite Load ◽  
Suitable Model ◽  
Cytokine Network ◽  
Th2 Response ◽  
Hamster Model

AbstractThe golden hamster is a suitable model for studying cutaneous leishmaniasis (CL) due to Leishmania (Viannia) braziliensis. Immunopathological mechanismsare wellstablished inthe L. (L.) major-mouse model, in which IL-4 instructs a Th2 response towards progressive infection. In the present study, we evaluatedthe natural history of L. braziliensis infection from its first stagesup to lesion establishment, with the aim ofidentifyingimmunological parameters associated with the disease outcome and parasitismfate. To this end, hamsters infected with 104, 105,or 106 promastigoteswere monitored duringthe first hours (4h, 24h), early (15, 30 days) and late (50 days) post-infection (pi) phases. Cytokines, iNOS and arginasegene expression were quantified in the established lesions by RT-PCR. Compared to the 105 or 106 groups, 104animals presented lower lesions sizes, less tissue damage,and lower IgG levels. Basal gene expression in normal skin was high for TGF-β, and intermediary for TNF, IL-6, and IL-4.At 4hpi, no cytokine induction was observed in the 104 group, while an upregulation of IL-6, IL-10, and IL-4 was observed in the 106 group. At 15dpi, lesion appearance was accompanied byan increasedexpression of all assessed cytokines, markedly in the 105 and 106 groups. Upregulation of all investigated cytokines was observed in the late phase, although less expressive in the 104 group. IFN-γ was the depending variable influencing tissue damage, while IL-6 was associatedto parasite load. The network correlating gene expression and clinical and laboratorial parameters indicated inoculum-independent associations at 15 and 30dpi.A strong positive network correlation was observed in the 104 group, but not in the105 or 106 groups. In conclusion, IL-4, IL-6, IL-10, and TGF-β are linkedto L. braziliensisprogression. However, a balanced cytokine network is the key for an immune response able to reduce the ongoing infection and reduce pathological damage.

scholarly journals Genome-Wide Association Study of Cell-Mediated Response in Dogs Naturally Infected by Leishmania infantum

2016 ◽  
Vol 84 (12) ◽  
pp. 3629-3637 ◽  
Author(s):  
Luís F. S. Batista ◽  
Yuri T. Utsunomiya ◽  
Thaís B. F. Silva ◽  
Raíssa A. Dias ◽  
Thaise Y. Tomokane ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Association Study ◽  
Leishmania Infantum ◽  
Genome Wide Association Study ◽  
Parasite Load ◽  
Genome Wide Association ◽  
Content Type ◽  
Genome Wide ◽  
Tnf Α ◽  
Ifn Γ

A genome-wide association study (GWAS) could unravel the complexity of the cell-mediated immunity (CMI) to canine leishmaniasis (CanL). Therefore, we scanned 110,165 single-nucleotide polymorphisms (SNPs), aiming to identify chromosomal regions associated with the leishmanin skin test (LST), lymphocyte proliferation assay (LPA), and cytokine responses to further understand the role played by CMI in the outcome of naturalLeishmania infantuminfection in 189 dogs. Based on LST and LPA, four CMI profiles were identified (LST−/LPA−, LST+/LPA−, LST−/LPA+, and LST+/LPA+), which were not associated with subclinically infected or diseased dogs. LST+/LPA+dogs showed increased interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) levels and mild parasitism in the lymph nodes, whereas LST−/LPA+dogs, in spite of increased IFN-γ, also showed increased interleukin-10 (IL-10) and transforming growth factor β (TGF-β) levels and the highest parasite load in lymph nodes. Low T cell proliferation under low parasite load suggested thatL. infantumwas not able to induce effective CMI in the early stage of infection. Altogether, genetic markers explained 87%, 16%, 15%, 11%, 0%, and 0% of phenotypic variance in TNF-α, TGF-β, LST, IL-10, IFN-γ, and LPA, respectively. GWAS showed that regions associated with TNF-α include the following genes:IL12RB1,JAK3,CCRL2,CCR2,CCR3, andCXCR6, involved in cytokine and chemokine signaling; regions associated with LST, includingCOMMD5andSHARPIN, involved in regulation of NF-κB signaling; and regions associated with IL-10, includingLTBP1andRASGRP3, involved in T regulatory lymphocytes differentiation. These findings pinpoint chromosomic regions related to the cell-mediated response that potentially affect the clinical complexity and the parasite replication in canineL. infantuminfection.

scholarly journals Hemostatic assessment of dogs associated with hepatic parasite load of Leishmania infantum chagasi

2016 ◽  
Vol 25 (2) ◽  
pp. 244-247
Author(s):  
Mariana de Medeiros Torres ◽  
Arleana do Bom Parto Ferreira de Almeida ◽  
Daphine Ariadne Jesus de Paula ◽  
Adriane Jorge Mendonça ◽  
Luciano Nakazato ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Rank Correlation ◽  
Immunological Response ◽  
Parasite Load ◽  
Serum Biochemistry ◽  
Screening Tests ◽  
Hemorrhagic Diathesis ◽  
Spearman’S Rank Correlation ◽  
Leishmania Infantum Chagasi

Abstract Leishmania infantum chagasi liver parasite load was compared to hemostatic abnormalities, as well as to clinical, laboratorial, and histopathological findings in dogs with visceral leishmaniasis. The liver parasite load of 30 dogs L. infantum chagasi naturally-infected was evaluated by quantitative real- time PCR and the results were compared with serum biochemistry and primary and secondary hemostasis findings. Moreover, hepatic histological lesions were described in these dogs. Prolonged bleeding time, prothrombin time (PT), and activated partial thromboplastin time (APTT), were observed in the group with visceral leishmaniasis. Eleven dogs presented inflammatory liver lesions, with predominance of mild multifocal mononuclear periportal hepatitis. No association between the presence of parasites and abnormalities in screening tests was observed by Spearman’s rank correlation coefficient. The clinical progression in leishmaniasis is associated with the occurrence of hemorrhagic diathesis, which depends not only on the presence of the parasite but also the inflammatory process, compromised immunological response, hepatic and renal failure in symptomatic dogs.

scholarly journals Synergistic Anti-Leishmanial Activities of Morphine and Imiquimod on Leishmania infantum (MCAN/ES/98/LIM-877)

2021 ◽  
Author(s):  
Fatemeh‌‌‌‌ Ghaffarifar ◽  
Masoud Foroutan ◽  
Soheila Molaei ◽  
Eslam Moradi-Asl
Keyword(s):  
Flow Cytometry ◽  
Leishmania Infantum ◽  
Parasite Load ◽  
Therapeutic Effects ◽  
Cytotoxic Effects ◽  
Low Concentrations ◽  
Ifn Γ ◽  
Cytokine Assay

Background: This study was performed to evaluate in vitro and in vivo Leishmanicidal potential of morphine (Mph), imiquimod (IQ), and their combination. Methods: Leishmania infantum promastigote and amastigote assays were performed at the presence of 0.015–150µM Mph, 0.04–416µM IQ, and their combination. The inhibition effects of these drugs on promastigotes were evaluated after 24, 48, and 72h. The cytotoxic effects of the drugs were evaluated by MTT as well as flow cytometry after 72h. We explored the therapeutic effects of Mph and IQ in BALB/c mice at the end of the treatment using parasite load de­termination and cytokine assay. One group of mice received Mph for three weeks before infection. Results: The results of promastigote and amastigote assays showed the cytotoxic effects of the drugs at low concentra­tions. The cytotoxic effects were higher on promastigotes than amastigotes (p< 0.05). There was a negative correlation between drug concentration and amastigote/promastigote viability. Imiquimod alone or combined with Mph showed remarkable cytotoxic effects at all concentrations (p< 0.05). Flow cytometry results revealed apoptosis in the parasite following exposure to the drug combinations. Accordingly, the reduction of parasite loads in the spleen and liver was observed (p< 0.05) with simultaneous increases in IFN-γ and IL-4. We believe that the in vivo leishmanicidal effect was mediated by Mph through IL-4 and by IQ through both IL-4 and IFN-γ. Conclusion: Results pointed out the promising effects of Mph and IQ at low concentrations, especially when combined.  

scholarly journals FML/QuilA-Vaccinated Dogs Naturally Infected with Leishmania infantum: Serum Cytokines, Clinicopathological Profile, and Parasitological Parameters

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Gregório Guilherme Almeida ◽  
Fernanda Morcatti Coura ◽  
Jonata de Melo Barbieri ◽  
Ana Carolina Junqueira Moura ◽  
Fabiola de Oliveira Paes-Leme ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Hematological Parameters ◽  
Parasite Burden ◽  
Parasite Load ◽  
Serum Levels ◽  
Canine Leishmaniasis ◽  
Th2 Response ◽  
Mild Disease ◽  
Clinicopathological Profile ◽  
G Ratio

Dogs are the main reservoir of Leishmania infantum in endemic regions. Canine leishmaniasis, caused by L. infantum, can progress to a chronic disease resulting in death. Vaccines have been developed with a certain degree of success. The pathogenesis of this disease is not completely understood, especially in previously vaccinated dogs. We herein described clinical data, parasite load, serum levels of cytokines, and the reservoir potential in vdogs vaccinated with the fucose-mannose ligand (FML)/QuilA saponin vaccine (Leishmune™) naturally infected (Vi) and compared to vaccinated not infected dogs (Vn). Thirty-four dogs from private owners were divided into two groups: vaccinated/infected and vaccinated/uninfected. Clinical evaluation, hematological and biochemical parameters, and serum levels of cytokines were measured by conventional methods. The parasite burden in the bone marrow was measured by quantitative real-time PCR, and the transmissibility of parasites to sand flies was assessed by xenodiagnosis. Clinical, biochemical, and hematological parameters of vaccinated infected dogs were mostly normal. Vi dogs developed mild disease with low clinical scores. Serum levels of IL-10 were higher in Vi dogs, and a strong correlation was observed in IL-4 levels and the A/G ratio in Vi dogs. These results suggest a role of TH2 response in Vi dogs, although more data is needed to better understand the disease in vaccinated dogs.

Leishmanicidal Activity of Plant Extracts from Sefrou, a Moroccan Focus of Leishmaniasis, against Various Leishmania Parasites in the Promastigote Stage

2018 ◽  
Vol 17 (2) ◽  
pp. 83-89 ◽  
Author(s):  
I. Zeouk ◽  
A. Et-Touys ◽  
M. Balouiri ◽  
H. Fellah ◽  
A. El Ouali Lalami ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Plant Extracts ◽  
Leishmania Infantum ◽  
Leishmania Major ◽  
Local Population ◽  
Public Health Problem ◽  
World Health ◽  
Total Phenolic ◽  
Leishmania Tropica ◽  
Cistus Salviifolius

According to the World Health Organization, leishmaniasis remains a major worldwide public health problem. The province of Sefrou located in the center of Morocco is a focus of cutaneous leishmaniasis. The present study aims at evaluating the antileishmanial potential of Berberis sp.,Crataegus oxyacantha, Cistus salviifolius, Ephedra altissima and Lavandula dentatafrequently used by the local population. Methanolic extracts were tested against the promastigote form ofLeishmania tropica, Leishmania majorandLeishmania infantumusing tetrazolium-based colorimetric (MTT) assay. The total phenol and flavonoids content of all extracts were determined using the Folin–Ciocalteu reagent, aluminum chloride, and potassium acetate solutions respectively. The plant extracts exhibited antileishmanial activity with variability depending on the tested strain and the plant species compared to Glucantime® used as control (IC50 (the half maximal inhibitory concentration) > 1,000 μg/mL). The best inhibition was observed with Berberis sp., againstLeishmania major(IC50 = 394.40 ± 3.02 μg/ml), andEphedra altissima(reported for the first time) againstLeishmania infantum(IC50 = 490.84 ± 3.15 μg/mL).Leishmania tropicahas shown the same sensitivity behavior toward the five extracts (in average IC50 = 540 ± 11.20 μg/mL). The total phenolic content was higher forCrataegus oxyacanthaandCistus salviifolius(140.67 ± 3.17 μg eq Gallic Acid (GA)/ mg of Extract (E) and 133.83 ± 9.03 μg eq GA/mg of E respectively), while flavonoid was higher forCistus salviifoliusandLavandula dentata(57.92 ± 2.46 μg eq Quercetin (Que)/ mg of Extract (E) and 41.53 ± 1.74 μg eq Que/mg of E). All the tested extracts present some promising aspects that may cure cutaneous leishmaniasis in the center of Morocco; further bioguided assays are needed to isolate the fractions and the bioactive molecule.

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