Browsing by Author "Fujiwara, Ricardo Toshio"

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    Antigenicity of a whole parasite vaccine as promising candidate against canine leishmaniasis.
    (2008) Giunchetti, Rodolfo Cordeiro; Reis, Alexandre Barbosa; Lemos, Denise da Silveira; Martins Filho, Olindo Assis; Oliveira, Rodrigo Corrêa de; Bethony, Jeffrey Michael; Vale, André Macedo; Quetz, Josiane da Silva; Bueno, Lilian Lacerda; Silva, João Carlos França da; Nascimento, Evaldo do; Mayrink, Wilson; Fujiwara, Ricardo Toshio
    Human visceral leishmaniasis, one of the most important zoonoses, is caused by the protozoaLeishmania chagasi(syn. L. infantum ) and is present as a fatal disease common in South America and Europe where dogs and wild canids are the main reservoirs. A vaccine against visceral leishmaniasis would be an important tool in the control of this disease in dogs. Although the current strategies for vac-cination against leishmaniasis are based on the use of recombinant antigens, killed vaccines are still attractive in terms of stability of their biochemical composition and antigenicity, cost, and safety. Here we evaluate the immunogenicity of a whole parasite vaccine as a prom-ising candidate against canine leishmaniasis, demonstrated by cellular reactivity, changes in the cellular profile of the peripheral blood and by the differential production of immunoglobulins. Our results showed that immunization elicited mainly a strong cellular reactivity and increase in T-lymphocytes, particularly the subpopulation CD8 + that would be related to the control of tissue parasitism. In addi-tion, a higher production of anti- Leishmania total IgG, characterized by mixed isotypes profile (IgG1 and IgG2), was demonstrated.
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    Avaliação da dose-resposta e da associação de adjuvantes na potência de vacinas quiméricas contra leishmaniose visceral : estudo de fase I em camundongos BALB/c.
    (2020) Ostolin, Thais Lopes Valentim Di Paschoale; Reis, Alexandre Barbosa; Brito, Rory Cristiane Fortes de; Reis, Alexandre Barbosa; Brito, Rory Cristiane Fortes de; Fujiwara, Ricardo Toshio; Borges, William de Castro
    No Brasil, a leishmaniose visceral canina (LVC) encontra-se em expansão sendo um sério problema de saúde pública. A alta prevalência de cães infectados reforça a necessidade de uma vacina para ser empregada em campanhas de vacinação de forma profilática. Nesse trabalho foram avaliadas duas quimeras desenhadas a partir do mapeamento de epítopos de células T pertencentes a proteínas de Leishmania infantum descritas na literatura como candidatas vacinais. O objetivo do estudo foi avaliar a dose-resposta e o efeito da associação de adjuvantes na eficácia de vacinas quiméricas contra a leishmaniose visceral em camundongos BALB/c. Os animais foram divididos em 14 grupos Salina, Saponina e Monofosforil lipídio A (SM) e quimeras A e B, nas doses de 5, 10 e 20 g, associados ou não aos adjuvantes. Esses foram imunizados com 3 doses, com intervalo de 15 dias entre as doses, e desafiados com 1x107 promastigotas de L. infantum. Foi avaliada a atividade proliferativa de linfócitos T totais (CD3+ ) e suas subpopulações (CD3+CD4+ e CD3+CD8+ ) e a produção de citocinas intracitoplasmáticas (IL-2, IFN-, TNF-, IL-4 e IL-10) após estímulo com antígeno solúvel de L. infantum (ASLi) por citometria de fluxo. Além disso, foi determinada a produção de óxido nítrico (NO) em sobrenadante de cultura de esplenócitos estimulados com ASLi e produção de imunoglobulinas murinas anti-Leishmania (IgG total, IgG1 e IgG2) no soro dos camundongos por ELISA. A quantificação da carga parasitária foi feita no baço por PCR em tempo real (qPCR). Ambas quimeras nas três doses avaliadas, apresentaram aumento da proliferação de linfócitos T e suas subpopulações quando comparadas ao grupo Salina. Quando associadas aos adjuvantes, o mesmo comportamento foi observado sendo o aumento em comparação aos grupos Salina e SM. Observou-se aumento de células T CD4+ e CD8+ produtoras de IFN-, TNF- e IL-2, enquanto houve redução de IL-4 e IL-10, tanto em A quanto em B nas três doses. Cabe ressaltar, que em B na dose de 5 g associada a SM houve aumento na produção de IFN- e IL-2 e redução de IL-4 e IL-10 pelos linfócitos TCD4+ em comparação ao grupo Salina. Os resultados da reatividade anti-Leishmania, mostraram que as proteínas quiméricas A e B aumentaram a produção de IgG total e IgG2 nas três doses avaliadas. Quando associadas a SM, apenas a proteína quimérica A, mostrou-se reativa. Em relação ao subclasse IgG1, houve aumento nas doses de 5 g e 10 g. E para IgG2 houve diferença significativa das doses de 5 e 10 g com a dose de 20 g. Quando quantificamos a carga parasitária foi observado que as proteínas quiméricas sozinhas não foram capazes de reduzir a carga no baço dos animais. Em contrapartida, quando foram associadas ao sistema SM, houve redução da carga parasitária no baço em todas as doses avaliadas para ambas quimeras. Observou-se aumento na produção de NO em todos grupos que foram imunizados com as quimeras associadas ao sistema SM. Os resultados obtidos foram promissores, demonstrando que mesmo em doses reduzidas as quimeras foram capazes de desencadear uma resposta imunológica satisfatória. Os resultados mostram que as duas quimeras sozinhas e ou associadas ao sistema de adjuvantes foram imunogênicas mesmo em doses reduzidas. Além disso, esse estudo contribuirá para o desenvolvimento de novas vacinas contra a LV.
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    Cell recruitment and cytokines in skin mice sensitized with the vaccine adjuvants : saponin, incomplete Freund's adjuvant, and monophosphoryl Lipid A.
    (2012) Souza, Juliana Vitoriano de; Moreira, Nádia das Dores; Carvalho, Andréa Teixeira de; Carneiro, Cláudia Martins; Mathias, Fernando Augusto Siqueira; Vieira, Paula Melo de Abreu; Giunchetti, Rodolfo Cordeiro; Moura, Sandra Aparecida Lima de; Fujiwara, Ricardo Toshio; Melo, Maria Norma; Reis, Alexandre Barbosa
    Vaccine adjuvants are substances associated with antigens that are fundamental to the formation of an intense, durable, and fast immune response. In this context, the use of vaccine adjuvants to generate an effective cellular immune response is crucial for the design and development of vaccines against visceral leishmaniasis. The objective of this study was to evaluate innate inflammatory response induced by the vaccine adjuvants saponin (SAP), incomplete Freund’s adjuvant (IFA), and monophosphoryl lipid A (MPL). After a single dose of adjuvant was injected into the skin of mice, we analyzed inflammatory reaction, selective cell migration, and cytokine production at the injection site, and inflammatory cell influx in the peripheral blood. We found that all vaccine adjuvants were able to promote cell recruitment to the site without tissue damage. In addition, they induced selective migration of neutrophils, macrophages, and lymphocytes. The influx of neutrophils was notable at 12 h in all groups, but at other time points it was most evident after inoculation with SAP. With regard to cytokines, the SAP led to production of interleukin (IL)-2, IL-6, and IL-4. IFA promoted production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, IL-17, IL-4, and IL-10. We also observed that MPL induced high production of IL-2, TNF-α, and IFN-γ, in addition to IL-6, IL-17, and IL-10. In peripheral blood, values of certain cell populations in the local response changed after stimulation. Our data demonstrate that the three vaccine adjuvants stimulate the early events of innate immune response at the injection site, suggesting their ability to increase the immunogenicity of co-administered antigens. Moreover, this work provides relevant information about elements of innate and acquired immune response induced by vaccine adjuvants administered alone.
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    Comparative genomics of canine-isolated Leishmania (Leishmania) amazonensis from an endemic focus of visceral leishmaniasis in Governador Valadares, southeastern Brazil.
    (2017) Valdivia Rodríguez, Hugo Oswaldo; Almeida, Laila Viana de; Roatt, Bruno Mendes; Cunha, João Luís Reis; Pereira, Agnes Antônia Sampaio; Gontijo, Célia Maria Ferreira; Fujiwara, Ricardo Toshio; Reis, Alexandre Barbosa; Sanders, Mandy J.; Cotton, James A.; Bartholomeu, Daniella Castanheira
    Leishmaniasis is a highly diverse group of diseases caused by kinetoplastid of the genus Leishmania. These parasites are taxonomically diverse, with human pathogenic species separated into two subgenera according to their development site inside the alimentary tract of the sand fly insect vector. The disease encompasses a variable spectrum of clinical manifestations with tegumentary or visceral symptoms. Among the causative species in Brazil, Leishmania (Leishmania) amazonensis is an important etiological agent of human cutaneous leishmaniasis that accounts for more than 8% of all cases in endemic regions. L. (L.) amazonensis is generally found in the north and northeast regions of Brazil. Here, we report the first isolation of L. (L.) amazonensis from dogs with clinical manifestations of visceral leishmaniasis in Governador Valadares, an endemic focus in the southeastern Brazilian State of Minas Gerais where L. (L.) infantum is also endemic. These isolates were characterized in terms of SNPs, chromosome and gene copy number variations, confirming that they are closely related to a previously sequenced isolate obtained in 1973 from the typical Northern range of this species. The results presented in this article will increase our knowledge of L. (L.) amazonensis-specific adaptations to infection, parasite survival and the transmission of this Amazonian species in a new endemic area of Brazil.
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    Cytokine and nitric oxide patterns in dogs immunized with LBSap vaccine, before and after experimental challenge with Leishmania chagasi plus saliva of Lutzomyia longipalpis.
    (2013) Resende, Lucilene Aparecida; Roatt, Bruno Mendes; Soares, Rodrigo Dian de Oliveira Aguiar; Viana, Kelvinson Fernandes; Mendonça, Ludmila Zanandreis de; Lanna, Mariana Ferreira; Lemos, Denise da Silveira; Oliveira, Rodrigo Corrêa de; Martins Filho, Olindo Assis; Fujiwara, Ricardo Toshio; Carneiro, Cláudia Martins; Reis, Alexandre Barbosa; Giunchetti, Rodolfo Cordeiro
    In the studies presented here, dogs were vaccinated against Leishmania (Leishmania) cha-gasi challenge infection using a preparation of Leishmania braziliensis promastigote proteinsand saponin as adjuvant (LBSap). Vaccination with LBSap induced a prominent type 1immune response that was characterized by increased levels of interleukin (IL-) 12 andinterferon gamma (IFN- _) production by peripheral blood mononuclear cells (PBMC) uponstimulation with soluble vaccine antigen. Importantly, results showed that this type ofresponsiveness was sustained after challenge infection; at day 90 and 885 after L. chagasichallenge infection, PBMCs from LBSap vaccinated dogs produced more IL-12, IFN- _ andconcomitant nitric oxide (NO) when stimulated with Leishmania antigens as comparedto PBMCs from respective control groups (saponin, LB- treated, or non-treated controldogs). Moreover, transforming growth factor (TGF)- _ decreased in the supernatant of SLcA-stimulated PBMCs in the LBSap group at 90 days. Bone marrow parasitological analysisrevealed decreased frequency of parasitism in the presence of vaccine antigen. It is con-cluded that vaccination of dogs with LBSap vaccine induced a long-lasting type 1 immuneresponse against L. chagasi challenge infection.
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    Effect on cellular recruitment and the innate immune response by combining saponin, monophosphoryl lipid-A and incomplete freund’s adjuvant with Leishmania (Viannia) braziliensis antigens for a vaccine formulation.
    (2019) Souza, Juliana Vitoriano de; Mathias, Fernando Augusto Siqueira; Moreira, Nádia das Dores; Soares, Rodrigo Dian de Oliveira Aguiar; Vieira, Paula Melo de Abreu; Carvalho, Andréa Teixeira de; Carneiro, Cláudia Martins; Giunchetti, Rodolfo Cordeiro; Brito, Rory Cristiane Fortes de; Fujiwara, Ricardo Toshio; Roatt, Bruno Mendes; Melo, Maria Norma; Reis, Alexandre Barbosa
    The poor immunogenicity displayed by some antigens has encouraged the development of strategies to improve the immune response and safety of vaccine candidates, resulting in an intense search for substances that potentiate vaccine response. Adjuvants have these properties helping vaccine candidates to induce a strong, durable, and fast immune response. In this study, we evaluated the specific immune response of adjuvants alone, Saponin (SAP), Incomplete Freund’s Adjuvant (IFA) and Monophosphoryl lipid-A SE (MPL-SE ) and in combination with total antigen of L. braziliensis (LB): LBSAP, LBIFA and LBMPL. The specific immune response induced by these compositions demonstrated that they were powerfully immunogenic, increasing cellular infiltration in the skin. Draining lymph nodes cultures showed that LBIFA and LBMPL have higher ability to increase the capacity of APCs to present antigens, with increased frequency of CD11c+ CD86+ cells. SAP, MPL, LBSAP, LBIFA and LBMPL could activate lymphocytes increasing expression of CD69 and CD25. LBSAP group was an excellent inducer of pro-inflammatory cytokines at 24 h. At 48 h, higher cytokines production was observed in IFA, LBIFA, MPL and LBMPL groups. Our data demonstrate that LBSAP and LBMPL are potential formulations to be tested in other experimental models. Also, the data obtained could expand the knowledge about immune response after sensitization and also contribute to the development of safe, immunogenic and effective vaccines.
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    Epitope mapping of the HSP83.1 protein of Leishmania braziliensis discloses novel targets for immunodiagnosis of tegumentary and visceral clinical forms of leishmaniasis.
    (2014) Souza, Daniel Menezes; Mendes, Tiago Antônio de Oliveira; Gomes, Matheus de Souza; Cunha, João Luís Reis; Nagem, Ronaldo Alves Pinto; Carneiro, Cláudia Martins; Coelho, Eduardo Antônio Ferraz; Galvão, Lúcia Maria da Cunha; Fujiwara, Ricardo Toshio; Bartholomeu, Daniella Castanheira
    Gold standard serological diagnostic methods focus on antigens that elicit a strong humoral immune response that is specific to a certain pathogen. In this study, we used bioinformatics approaches to identify linear B-cell epitopes that are conserved among Leishmania species but are divergent from the host species Homo sapiens and Canis familiaris and from Trypanosoma cruzi, the parasite that causes Chagas disease, to select potential targets for the immunodiagnosis of leishmaniasis. Using these criteria, we selected heat shock protein 83.1 of Leishmania braziliensis for this study. We predicted three linear B-cell epitopes in its sequence. These peptides and the recombinant heat shock protein 83.1 (rHSP83.1) were tested in enzyme-linked immunosorbent assays (ELISAs) against serum samples from patients with tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL) and from dogs infected with Leishmania infantum (canine VL [CVL]). Our data show that rHSP83.1 is a promising target in the diagnosis of TL. We also identified specific epitopes derived from HSP83.1 that can be used in the diagnosis of human TL (peptide 3), both human and canine VL (peptides 1 and 3), and all TL, VL, and CVL clinical manifestations (peptide 3). Receiver operating characteristic (ROC) curves confirmed the superior performance of rHSP83.1 and peptides 1 and 3 compared to that of the soluble L. braziliensis antigen and the reference test kit for the diagnosis of CVL in Brazil (EIE-LVC kit; Bio-Manguinhos, Fiocruz). Our study thus provides proof-of-principle evidence of the feasibility of using bioinformatics to identify novel targets for the immunodiagnosis of parasitic diseases using proteins that are highly conserved throughout evolution.
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    Hookworm products ameliorate dextran sodium sulfate-induced colitis in BALB/c mice.
    (2011) Cançado, Guilherme Grossi Lopes; Fiuza, Jacqueline Araújo; Paiva, Nívia Carolina Nogueira de; Lemos, Lucas de Carvalho Dhom; Ricci, Natasha Delaqua; Guimarães, Pedro Henrique Gazzinelli; Martins, Virgílio Gandra; Bartholomeu, Daniella Castanheira; Corrêa, Deborah Aparecida Negrão; Carneiro, Cláudia Martins; Fujiwara, Ricardo Toshio
    Background: Several lines of evidence have shown that helminthiasis can significantly reduce disease severity in animal models of intestinal inflammation, airway inflammation/hyperreactivity, diabetes, and multiple sclerosis. Identification and characterization of helminth-derived immunomodulatory molecules that contribute to anticolitis effects could lead to new therapeutic approaches in inflammatory bowel diseases (IBDs) without the need for helminth infection. We evaluated the therapeutic potential of adult human hookworm, Ancylostoma ceylanicum, crude (Aw) and excreted/secreted (ES) products on dextran sulfate sodium (DSS)-induced colitis in BALB/c mice. Methods: Colitis was induced by 5% DSS oral administration for 7 days. Clinical disease severity was monitored daily during concomitant intraperitoneal treatment with helminth-derived products. Additionally, several pathways of immunological modulation induced by A. ceylanicum products (MPO, EPO, Th1, Th2, and Th17 cytokine responses) in the inflamed intestinal microenvironment were assessed. Finally, the histopathological profile of the colon was characterized. Results: Hookworm products are able to modulate the potent proinflammatory response induced by DSS, mainly through the downregulation of Th1 and Th17 cytokines. These proteins also reduce clinical and colonic microscopic inflammation scores as well as EPO and MPO activity. Conclusions: Ancylostoma ceylanicum Aw and ES mediators have an important therapeutic potential in experimental colitis in mice, which may provide a more socially acceptable form of therapy for patients with IBDs as opposed to using living worms. Our results support the urgency of further isolation and recombinant expression of active hookworm products responsible for the beneficial effects on colitis.
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    Immunogenicity in dogs of three recombinant antigens (TSA, LeiF and LmSTI1) potential vaccine for canine visceral leishmaniasis.
    (2005) Fujiwara, Ricardo Toshio; Vale, André Macedo; Silva, João Carlos França da; Costa, Roberto Teodoro da; Quetz, Josiane da Silva; Martins Filho, Olindo Assis; Reis, Alexandre Barbosa; Oliveira, Rodrigo Corrêa de; Coelho, George Luiz Lins Machado; Bueno, Lilian Lacerda; Bethony, Jeffrey Michael; Frank, Glen; Nascimento, Evaldo do; Genaro, Odair; Mayrink, Wilson; Reed, Steven G.; Campos Neto, Antonio
    Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway. Because of the high degree of conservation, these antigens might be useful vaccine candidates for VL as well. In the present study, using the dog model of the visceral disease, we evaluated the immunogenicity of these three antigens formulated with two different adjuvants, MPL-SE® and AdjuPrime®. The results were compared with a whole parasite vaccine formulated with BCG as the adjuvant. In order to investigate if sensitization with the recombinant antigens would result in recognition of the corresponding native parasite antigens upon infection, the animals were exposed for four weeks after the termination of the immunization protocol with the recombinant antigens to a low number of L. chagasi promastigotes, an etiological agent of VL. Immune response was evaluated by quantitative ELISA in the animal sera before and after exposure to the viable parasites. Both antigen specific IgG1 and IgG2 antibody levels were measured. Immunization of dogs with the recombinant antigens formulated in either MPL-SE® or AdjuPrime® resulted in high antibody levels particularly to LmSTI1. In addition, this immunization although to low levels, resulted in the development of antibody response to the whole parasite lysate. Importantly, experimental exposure with low numbers of culture forms of L. chagasi promastigotes caused a clear boost in the immune response to both the recombinant antigens and the corresponding native molecules. The boost response was predominantly of the IgG2 isotype in animals primed with the recombinant antigens plus MPL-SE®. In contrast, animals primed with the recombinant antigens formulated in AdjuPrime® as well as animals vaccinated with crude antigen preparation responded with mixed IgG1/IgG2 isotypes. These results point to the possible use of this antigen cocktail formulated with the adjuvant MPL-SE® in efficacy field trials against canine VL.
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    In vitro activity evaluation of seven Brazilian Asteraceae against cancer cells and Leishmania amazonensis.
    (2019) Silva, Ana Cláudia Nogueira da; Nascimento, Renato Malveira Carreiro do; Rodrigues, Débora Caroline do Nascimento; Ferreira, Paulo Michel Pinheiro; Pessoa, Claudia do Ó; Lima, Daisy Jereissati Barbosa; Moraes Filho, Manoel Odorico de; Almeida, Raquel Martins de; Ferreira, Sebastião Rodrigo; Fujiwara, Ricardo Toshio; Nascimento, Andréa Mendes do
    Natural products are a very productive leading source of compounds for the development of medicines. The aim of this research was to investigate the in vitro antiproliferative and antileishmanial activities of 21 extracts from 7 Asteraceae species. Dried aerial parts of Asteraceae plant species were extracted using organic solvents in order of increasing polarities. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, and nine extracts (43%) displayed moderate to high in vitro antiproliferative activity against human cancer cell lines HCT-116, OVCAR-8 and SF-295. Two crude extracts displaying antiproliferative activity were fractionated and yielded a fraction rich in lupeol acetate, a fraction rich in lupeol and 5,7,3′,4′-tetrahydroxyflavone-7-O-β-D-glucopyranoside. The antileishmanial activity was evaluated by amastigotes growth inhibition test in Leishmania amazonensis, and three extracts showed promising activity. Phytochemical screening of all plant extracts was also made for terpenoids, flavonoids, tannins, alkaloids and saponins.
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    Leishmania eukaryotic elongation Factor-1 beta protein is immunogenic and induces parasitological protection in mice against Leishmania infantum infection.
    (2021) Santos, Thaís Teodoro de Oliveira; Machado, Amanda Sanchez; Ramos, Fernanda Fonseca; Silva, João Augusto Oliveira da; Lage, Daniela Pagliara; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Cardoso, Mariana Santos; Siqueira, Williane Fernanda; Martins, Vívian Tamietti; Ribeiro, Fernanda Ludolf; Reis, Thiago Alves Rosa dos; Carvalho, Lívia Mendes; Freitas, Camila Simões de; Bandeira, Raquel Soares; Silva, Alessandra M.; Oliveira, Jamil Silvano de; Moreira, Ricardo Luiz Fontes; Fujiwara, Ricardo Toshio; Roatt, Bruno Mendes; Chávez Fumagalli, Miguel Angel; Humbert, Maria Victoria; Teixeira, Antônio Lúcio; Coelho, Eduardo Antônio Ferraz
    Treatment for visceral leishmaniasis (VL) is hampered mainly by the toxicity and/or high cost of antileishmanial drugs. What is more, variability on sensitivity and/or specificity of diagnostic tests hinders effective disease management. In this context, prophylactic vaccination should be considered as a strategy to prevent disease. In the present study, immunogenicity of the Leishmania eukaryotic Elongation Factor-1 beta (EF1b) protein, classified as a Leishmania virulence factor, was evaluated in vitro and in vivo and tested, for the first time, as a vaccine candidate against Leishmania infantum infection. The antigen was administered as DNA vaccine or as recombinant protein (rEF1b) delivered in saponin. BALB/c mice immunization with a DNA plasmid and recombinant protein plus saponin induced development of specific Th1-type immunity, characterized by high levels of IFN-γ, IL-12, GM-CSF, both T cell subtypes and antileishmanial IgG2a isotype antibodies, before and after infection. This immunological response to the vaccines was corroborated further by parasitological analysis of the vaccinated and then challenged mice, which showed significant reductions in the parasite load in their liver, spleen, bone marrow and draining lymph nodes, when compared to the controls. Vaccination using rEF1b/saponin induced a more robust Th1 response and parasitological protection when compared to the DNA vaccine. Furthermore, in vitro analysis of lymphoproliferation, IFN-γ and IL-10 levels in human PBMC cultures showed as well development of a specific Th1-type response. In conclusion, data suggest that EF1b could be a promising vaccine candidate to protect against L. infantum infection.
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    Multicomponent LBSap vaccine displays immunological and parasitological profiles similar to those of Leish-Tec® and Leishmune® vaccines against visceral leishmaniasis.
    (2016) Mendonça, Ludmila Zanandreis de; Resende, Lucilene Aparecida; Lanna, Mariana Ferreira; Soares, Rodrigo Dian de Oliveira Aguiar; Roatt, Bruno Mendes; Castro, Renata Alves de Oliveira e; Batista, Maurício Azevedo; Lemos, Denise da Silveira; Estanislau, Juliana de Assis Silva Gomes; Fujiwara, Ricardo Toshio; Rezende, Simone Aparecida; Martins Filho, Olindo Assis; Oliveira, Rodrigo Corrêa de; Dutra, Walderez Ornelas; Reis, Alexandre Barbosa; Giunchetti, Rodolfo Cordeiro
    Background: In past years, many researchers have sought canine visceral leishmaniasis (CVL) prevention through the characterization of Leishmania antigens as vaccine candidates. Despite these efforts, there is still no efficient vaccine for CVL control. Methods: In the present study, we performed a pre-clinical vaccine trial using BALB/c mice to compare the effects of the multicomponent LBSap vaccine with those of Leish-Tec® and Leishmune®. Blood was collected to determine the frequency of peripheral blood cells and to evaluate hematologic and immunophenotypic parameters. Liver and spleen samples were collected for parasitological quantification, and spleen samples were used to access the cytokine profile. Results: When measuring total IgG and IgG1 anti-Leishmania levels after the third vaccination and L. infantum challenge, it was evident that all vaccines were able to induce humoral immune response. Regarding the innate immune response, increased levels of NK CD3-CD49+ cells were the hallmark of all vaccinated groups, whereas only the Leish-Tec® group displayed a high frequency of CD14+ monocytes after L. infantum challenge. Moreover, CD3+CD4+ T cells were the main circulating lymphocytes induced after L. infantum challenge with all evaluated vaccines. Importantly, after L. infantum challenge, splenocytes from the Leishmune® vaccine produced high levels of IL-2, whereas a prominent type 1 immune response was the hallmark of the LBSap vaccine, which presented high levels of IL-2, IL-6, TNF-α, and IFN-γ. The efficacy analysis using real-time polymerase chain reaction demonstrated a reduction in the parasitism in the spleen (Leishmune®: 64 %; LBSap: 42 %; and Leish-Tec®: 36 %) and liver (Leishmune®: 71 %; LBSap: 62 %; and Leish-Tec®: 48 %). Conclusions: The dataset led to the conclusion that the LBSap vaccination was able to induce immune and efficacy profiles comparable with those of commercial vaccines, thus demonstrating its potential as a promising vaccine candidate for visceral leishmaniasis control.