Avaliação do potencial protetor da imunização intranasal com vesículas extracelulares de Leishmania (Leishmania) amazonensis em camundongos BALB/c
Data
2024-09-13
Autores
Morais, Aline Correia Costa de 
Orientadores
Batista, Patricia Xander
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Vesículas extracelulares (EVs) são partículas liberadas por células procarióticas e eucarióticas. A principal função das EVs é a comunicação célula-célula, uma vez que essas partículas carregam várias moléculas, como proteínas, lipídios, DNA e RNA. Parasitas do gênero Leishmania liberam EVs com propriedades imunomoduladoras capazes de estimular a produção de citocinas por macrófagos e monócitos e que modulam o curso da infecção experimental. Leishmania spp. é o agente etiológico da leishmaniose, doença endêmica em vários países. O tratamento para leishmaniose é longo e utiliza drogas com potencial tóxico, e vacinas para humanos ainda não estão disponíveis. Nosso grupo mostrou que EVs liberadas por Leishmania (Leishmania) amazonensis têm potencial protetor em protocolos de imunização intraperitoneal em camundongos BALB/c. No entanto, estudos adicionais são necessários para melhorar a proteção mediada por imunização com EVs de L. (L.) amazonensis. Neste estudo foram avaliados os efeitos da imunização intranasal com EVs liberadas por promastigotas de L. (L.) amazonensis com diferentes perfis de virulência (LT-P, com perfil atenuado de virulência; e IVD-P com perfil virulento) assim como os aspectos induzidos pós imunização. Camundongos BALB/c foram imunizados pela via intranasal quinzenalmente com 4 µg de EVs LT-P ou IVD-P. Após 15 dias da segunda imunização, os animais foram desafiados subcutaneamente na pata traseira com promastigotas de L. (L.) amazonensis. O efeito da imunização em camundongos BALB/c foi avaliado pelo tamanho das lesões, carga parasitária (diluição limitante) e análise histológica das lesões. As citocinas foram avaliadas por CBA (Cytometric Bead Array) no sobrenadante de cultura de esplenócitos reestimulados in vitro com EVs. Nossos resultados mostraram que o grupo imunizado com EVs provenientes de parasitas com perfil LT-P apresentou menor lesão e menor carga parasitária em relação ao grupo imunizado com EVs obtidas de parasitas com perfil IVD-P e grupo de animais não imunizados. Em relação ao perfil de citocinas, o grupo de animais imunizado com EVs provenientes de LT-P apresentou maior produção de IFN-a em relação aos grupos imunizados com EVs de IVD-P e não imunizados. A imunização prévia pela via intranasal com EVs de LT-P levou a diminuição do tamanho da lesão e carga parasitária nos animais desafiados com o parasita. Ainda, este grupo apresentou aumento da produção de citocina do perfil Th1 (IFN-a). Nossos resultados mostraram que a imunização intranasal com EVs é promissora e pode desencadear resposta protetora para infecção com L. (L.) amazonensis.
Extracellular vesicles (EVs) are particles released by prokaryotic and eukaryotic cells. The main function of EVs is cell-to-cell communication, since these particles carry proteins, lipids, DNA, and RNA. Leishmania spp. (aetiologic agent of leishmaniasis) release EVs with immunomodulatory properties capable of stimulating the production of cytokines by macrophages and monocytes and modulating the course of experimental infection. Treatment for leishmaniasis is long and uses drugs with toxic potential, and vaccines for humans are not yet available. Our group showed that EVs released by Leishmania (Leishmania) amazonensis showed a protective potential in intraperitoneal immunization protocols in BALB/c mice. However, further studies are needed to improve immunization-mediated protection with EVs of L. (L.) amazonensis. In this study, the effects of intranasal immunization with EVs released by L. (L.) amazonensis promastigotes with different virulence profiles (LT-P, with attenuated virulence profile; and IVD-P with virulent profile) as well as the immunological aspects induced after immunization were evaluated. BALB/c mice were immunized intranasally twice with 4 μg of EVs from LT-P or IVD-P. After 15 days of the second immunization, the animals were challenged subcutaneously on the hind leg with L. (L.) amazonensis promastigotes. The effect of immunization in BALB/c mice was evaluated by lesion size, parasite load (limiting dilution) and histological analysis of the lesions. Cytokines were evaluated by CBA (Cytometric Bead Array) in the culture supernatant of splenocytes restimulated in vitro with EVs. Our results showed that the group immunized with EVs from parasites with LT-P profile presented lower lesion and lower parasite load in relation to the group immunized with EVs obtained from parasites with IVD-P profile and group of non-immunized animals. Regarding the cytokine profile, the group of animals immunized with EVs from LT-P presented higher production of IFN-a in relation to the groups immunized with EVs of IVD-P and not immunized mice. Previous intranasal immunization with LT-P EVs led to a decrease in lesion size and parasite load in animals challenged with the parasite. In addition, this group showed increased cytokine production of the Th1 profile (IFN-a). Our results showed that intranasal immunization with EVs is promising and may trigger a protective response to L. (L.) amazonensis infection.
Extracellular vesicles (EVs) are particles released by prokaryotic and eukaryotic cells. The main function of EVs is cell-to-cell communication, since these particles carry proteins, lipids, DNA, and RNA. Leishmania spp. (aetiologic agent of leishmaniasis) release EVs with immunomodulatory properties capable of stimulating the production of cytokines by macrophages and monocytes and modulating the course of experimental infection. Treatment for leishmaniasis is long and uses drugs with toxic potential, and vaccines for humans are not yet available. Our group showed that EVs released by Leishmania (Leishmania) amazonensis showed a protective potential in intraperitoneal immunization protocols in BALB/c mice. However, further studies are needed to improve immunization-mediated protection with EVs of L. (L.) amazonensis. In this study, the effects of intranasal immunization with EVs released by L. (L.) amazonensis promastigotes with different virulence profiles (LT-P, with attenuated virulence profile; and IVD-P with virulent profile) as well as the immunological aspects induced after immunization were evaluated. BALB/c mice were immunized intranasally twice with 4 μg of EVs from LT-P or IVD-P. After 15 days of the second immunization, the animals were challenged subcutaneously on the hind leg with L. (L.) amazonensis promastigotes. The effect of immunization in BALB/c mice was evaluated by lesion size, parasite load (limiting dilution) and histological analysis of the lesions. Cytokines were evaluated by CBA (Cytometric Bead Array) in the culture supernatant of splenocytes restimulated in vitro with EVs. Our results showed that the group immunized with EVs from parasites with LT-P profile presented lower lesion and lower parasite load in relation to the group immunized with EVs obtained from parasites with IVD-P profile and group of non-immunized animals. Regarding the cytokine profile, the group of animals immunized with EVs from LT-P presented higher production of IFN-a in relation to the groups immunized with EVs of IVD-P and not immunized mice. Previous intranasal immunization with LT-P EVs led to a decrease in lesion size and parasite load in animals challenged with the parasite. In addition, this group showed increased cytokine production of the Th1 profile (IFN-a). Our results showed that intranasal immunization with EVs is promising and may trigger a protective response to L. (L.) amazonensis infection.