Millions of people worldwide are affected by leishmaniasis, caused by the parasite. Effective treatment is challenging due to the biological complexity of the parasite, drug toxicity, and increasing resistance to conventional drugs. To combat this disease, the development of specific strategies to target and selectively eliminate the parasite is crucial.
View Article and Find Full Text PDFVaccines (Basel)
February 2023
Background: The adjuvants' optimal dose and the administration route can directly influence the epitope recognition patterns and profiles of innate response. We aimed to establish the effect and the optimal dose of adjuvant systems for proposing a vaccine candidate to be employed with () .
Methods: We evaluated the adjuvants saponin (SAP), monophosphoryl lipid A (MPL) and resiquimod (R-848) isolated and combined as adjuvant systems in a lower dose corresponding to 25%, 33%, and 50% of each adjuvant total dose.
Pathogens
August 2022
The spleen plays a central role in human and canine visceral leishmaniasis, where the activation of the immune response occurs in one of the tissues where reproduces. Therefore, this organ is both a target to understand the mechanisms involved in the parasite control and a parameter for assessing the therapeutic response. In this sense, this study aimed to evaluate the main histological, immunological and parasitological aspects in the spleen of symptomatic dogs naturally infected by treated with the therapeutic vaccine LBMPL.
View Article and Find Full Text PDFMol Immunol
November 2022
Dogs are the most common domestic reservoir of Leishmania infantum, making canine visceral leishmaniasis (CVL) a serious public health issue. Identifying new methodologies that can mimic lymphoid and myeloid competence in naturally infected dogs could lower costs and save time in preliminary screenings of potential immunotherapeutic agents and vaccines against CVL. For that, we established a cell-to-cell communication approach between lymphocytes and myeloid cells from healthy, asymptomatic (infected, without apparent clinical signs) and symptomatic (infected with apparent clinical signs) dogs.
View Article and Find Full Text PDFCell Immunol
October 2022
The development of an immunogenic, effective, and safe vaccine is essential as an alternative for disease control. The present study aimed to evaluate the immunogenicity and efficacy potential of a polyepitope T-cell antigen candidate against visceral leishmaniasis in a murine model. BALB/c mice were immunized with three doses subcutaneously with Poly-T Leish alone or adjuvanted with Saponin plus Monophosphoryl lipid A, with 15-day intervals between doses, and challenged with 10 stationary-phase Leishmania infantum promastigotes via tail vein.
View Article and Find Full Text PDFVaccine
September 2022
In recent years, several advances have been observed in vaccinology especially for neglected tropical diseases (NTDs). One of the tools employed is epitope prediction by immunoinformatic approaches that reduce the time and cost to develop a vaccine. In this scenario, immunoinformatics is being more often used to develop vaccines for NTDs, in particular visceral leishmaniasis (VL) which is proven not to have an effective vaccine yet.
View Article and Find Full Text PDFCurr Res Immunol
November 2021
Visceral leishmaniasis (VL) is a serious and neglected disease present worldwide. Chemotherapy using pentavalent antimony (Sb) is the most practical and inexpensive strategy available for the VL treatment today, however, it has high toxicity. Alternatively, other drugs are used as viable leishmanicidal therapeutic options.
View Article and Find Full Text PDFParasitology
March 2022
The control of human visceral leishmaniasis (VL) is hard since there are no vaccines available as well as the treatment is hampered by toxicity and resistant parasites. Furthermore, as human, and canine VL causes immunosuppression, the combination of drugs with immunostimulatory agents is interesting to upregulate the immunity, reducing side-effects, improving treatment approaches against disease. Herein, we assessed the immunochemotherapy using miltefosine along with a vaccine formulated by Leishmania braziliensis antigens + saponin + monophosphoryl lipid-A (LBSapMPL) in L.
View Article and Find Full Text PDFCytokine
May 2022
The liver plays an important role in human and canine visceral leishmaniasis, then it is considered as target to understand the mechanisms involved in the parasite control and a parameter to assess therapeutic responses. In this sense, our study focuses on evaluating the major alterations in the liver by histological (morphometric parenchyma inflammation/semi-quantitative portal inflammation), immunohistochemical assays (parasitism), and qPCR (parasitism and cytokine gene expression) in Leishmania infantum naturally infected dogs and treated with LBMPL vaccine. Animals were divided in four groups: NI group (n = 5): uninfected and untreated dogs; INT group (n = 7): L.
View Article and Find Full Text PDFMol Immunol
January 2022
This study compared the therapeutic potential of the chemotherapy using meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes (Nano Sb) and immunotherapy with anti-canine IL-10 receptor-blocking monoclonal antibody (Anti IL-10R) on canine visceral leishmaniasis (CVL). Twenty mongrel dogs naturally infected by L. infantum, displaying clinical signs of visceral leishmaniasis were randomly divided in two groups.
View Article and Find Full Text PDFJ Ethnopharmacol
February 2022
Ethnopharmacological Relevance: Coffea arabica is commonly known for its cardiotonic and neurotonic activities, but in some places' folk medicine, like in Arabia and Africa, C. arabica is used to treat headache, migraine, the flu, anemia, oedema, asthenia, asthma, inflammation and wounds.
Aims Of The Study: The aims were to evaluate if the aqueous extracts of Coffea arabica, prepared from beans with different degrees of roasting, and their main chemical constituents could exert an in vivo anti-gouty effect.
Ethnopharmacological Relevance: Ethanolic extract of aerial parts from Lychnophora pinaster Mart. are used in traditional Brazilian medicine for treating pain, rheumatism and inflammation.
Aim Of The Study: Drugs for the treatment of gout present severe adverse effects, justifying the need to search for new therapeutic options.
Mol Immunol
September 2021
An important strategy to reduce the risk of visceral leishmaniasis (VL) in humans is to control the infection and disease progression in dogs, the domestic reservoir of Leishmania infantum parasites. Certain therapeutic strategies that modulate the host immune response show great potential for the treatment of experimental VL, restoring the impaired effector functions or decreasing host excessive responses. It is known that the overproduction of interleukin-10 (IL-10) promotes parasite replication and disease progression in human VL as well as in canine visceral leishmaniasis (CVL).
View Article and Find Full Text PDFVaccine
May 2021
In Brazil, canine visceral leishmaniasis is an important public health problem due to its alarming growth. The high prevalence of infected dogs reinforces the need for a vaccine for use in prophylactic vaccination campaigns. In the present study, we evaluate the immunogenicity and protection of the best dose of Chimera A selected through the screening of cytokines production important in disease.
View Article and Find Full Text PDFFront Bioeng Biotechnol
March 2021
[This corrects the article DOI: 10.3389/fbioe.2020.
View Article and Find Full Text PDFJ Ethnopharmacol
April 2021
Ethnopharmacological Relevance: Lychnophora trichocarpha and Lychnophora passerina are species used in folk medicine to treat inflammation, pain, and rheumatism. Previous studies have demonstrated the anti-inflammatory effect of ethanol extracts of these species and identified that sesquiterpene lactones contribute to this activity.
Aim Of The Study: Gout is an acute inflammatory arthritis caused by the deposition of monosodium urate (MSU) crystals in joints.
Front Bioeng Biotechnol
December 2020
Vaccines (Basel)
November 2020
In this study, we performed a phase I and II clinical trial in dogs to evaluate the toxicity and immunogenicity of LBSap-vaccine prototype, in comparison to Leishmune and Leish-Tec vaccines. Twenty-eight dogs were classified in four groups: (i) control group received 1 mL of sterile 0.9% saline solution; (ii) LBSap group received 600 μg of promastigotes protein and 1 mg of saponin adjuvant; (iii) Leishmune; and (iv) Leish-Tec.
View Article and Find Full Text PDFParasitol Res
December 2020
Leishmania spp. parasites have a complex biological cycle presenting basically two different morphological stages, the amastigote and promastigote forms. In vitro cultivation allows a more complete study of the biological aspects of these parasites, indicating better conditions for infection, immunoassay tests, drug evaluations, and vaccines.
View Article and Find Full Text PDFVisceral leishmaniasis (VL) is a severe disease caused by . Dogs are the parasite's main reservoir, favoring its transmission in the urban environment. The analysis of from infected dogs contributes to the identification of more virulent parasites, thereby supporting basic and applied studies such as vaccinal and therapeutic strategies.
View Article and Find Full Text PDFDrug Deliv Transl Res
December 2020
Near-infrared fluorescent dyes, such as IR780, are promising theranostics, acting as photosensitizers for photodynamic therapy and in vivo tracers in image-guided diagnosis. This work compared the uptake by macrophage-like cells of IR780 either physically associated or covalently attached to poly(D,L-lactide) (PLA) formulated as polymeric nanocapsules (NC) from a blend of PLA homopolymer and PLA-PEG block copolymer. The physicochemical characterization of both NC was conducted using asymmetric flow field-flow fractionation (AF4) analysis with static and dynamic light scattering and atomic force microscopy.
View Article and Find Full Text PDFVaccines (Basel)
May 2020
Many vaccine candidates against visceral leishmaniasis (VL) have been proposed; however, to date, none of them have been efficacious for the human or canine disease. On this basis, the design of leishmaniasis vaccines has been constantly changing, and the use of approaches to select specific epitopes seems to be crucial in this scenario. The ability to predict T cell-specific epitopes makes immunoinformatics an even more necessary approach, as in VL an efficient immune response against the parasite is triggered by T lymphocytes in response to spp.
View Article and Find Full Text PDF