LBMPL Vaccine Therapy Induces Progressive Organization of the Spleen Microarchitecture, Improved Th1 Adaptative Immune Response and Control of Parasitism in <i>Leishmania infantum</i> Naturally Infected Dogs
Bruno Mendes Roatt,
Jamille Mirelle de Oliveira Cardoso,
Levi Eduardo Soares Reis,
Gabriel José Lucas Moreira,
Letícia Captein Gonçalves,
Flávia de Souza Marques,
Nádia das Dores Moreira,
Paula Melo de Abreu Vieira,
Rodrigo Dian de Oliveira Aguiar-Soares,
Rodolfo Cordeiro Giunchetti,
Alexandre Barbosa Reis
Affiliations
Bruno Mendes Roatt
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Jamille Mirelle de Oliveira Cardoso
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Levi Eduardo Soares Reis
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Gabriel José Lucas Moreira
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Letícia Captein Gonçalves
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Flávia de Souza Marques
Laboratório de Morfopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Nádia das Dores Moreira
Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 21941-902, Rio de Janeiro, Brazil
Paula Melo de Abreu Vieira
Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Rodrigo Dian de Oliveira Aguiar-Soares
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
Rodolfo Cordeiro Giunchetti
Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-013, Minas Gerais, Brazil
Alexandre Barbosa Reis
Laboratório de Imunopatologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto 35400-000, Minas Gerais, Brazil
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 Leishmania infantum 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 L. infantum treated with the therapeutic vaccine LBMPL. For this, dogs were divided into four groups: dogs uninfected and untreated (NI group); L. infantum-infected dogs that were not treated (INT group); L. infantum-infected dogs that received treatment only with monophosphoryl lipid A adjuvant (MPL group); and L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis promastigote proteins associated with MPL adjuvant (LBMPL group). Ninety days after the therapeutics protocol, the dogs were euthanized and the spleen was collected for the proposed evaluations. Our results demonstrated a reduction of hyperplasia of red pulp and follicular area of white pulp, increased mRNA expression of IFN-γ, TNF-α, IL-12 and iNOS, and decreased IL-10 and TGF-β1, and intense reduction of splenic parasitism in dogs treated with the LBMPL vaccine. These results possibly suggest that the pro-inflammatory environment promoted the progressive organization of the splenic architecture favoring the cellular activation, with consequent parasite control. Along with previously obtained data, our results propose the LBMPL vaccine as a possible treatment strategy for canine visceral leishmaniasis (CVL).
