Resposta imune a antígenos recombinantes de Leishmania e imuno-modulação na leishmaniose tegumentar

A leishmaniose de modo geral vem sendo amplamente estudada e diversas questões relacionadas aos aspectos imunológicos têm sido abordadas como caracterização e modulação da resposta imune. A linha de pesquisa abordada nesta tese visa caracterizar a resposta imune a antígenos recombinantes de Leishmania em pacientes com leishmaniose visceral e leishmaniose tegumentar e, avaliar aspectos relacionados à modulação da resposta imune na leishmaniose tegumentar. No primeiro artigo, tendo em vista a dificuldade do diagnóstico precoce e correto da leishmaniose visceral, avaliamos a capacidade de três antígenos recombinantes (rH2A, KMP11 e Proteína “Q”) de Leishmania serem utilizados em teste sorológico e realizar o diagnóstico diferencial entre infecção subclínica por L. chagasi e doença. A sensibilidade e a especificidade do teste sorológico para diagnóstico da leishmaniose visceral foi de 100% para os três antígenos recombinantes estudados e em relação ao diagnóstico diferencial o KMP11 foi o antígeno que apresentou melhor capacidade de ser utilizado para distinguir entre a doença ativa e a infecção por L. chagasi. Prosseguindo o estudo com antígenos recombinantes de Leishmania, no segundo artigo, mas visando avaliar aspectos relacionados à modulação da resposta imune em pacientes com leishmaniose cutânea e leishmaniose mucosa, células mononucleares do sangue periférico destes pacientes foram estimuladas com antígeno solúvel de Leishmania e adicionados os antígenos recombinantes LACK e KMP11 – antígenos indutores de IL-10. Os resultados encontrados mostraram que na leishmaniose cutânea, ambos os antígenos foram capazes de suprimir a resposta de IFN- através da produção de IL-10, mas na leishmaniose mucosa essa supressão não foi observada, mesmo havendo produção de IL-10 pelos antígenos recombinantes. Visando aprofundar o conhecimento da resposta imune em pacientes com leishmaniose cutânea e com leishmaniose mucosa, no terceiro artigo, avaliamos o papel de moléculas co-estimulatórias, marcadores de ativação de células T na modulação da resposta imune, além de determinar a capacidade de citocinas (IL-2, IL-12, IL-15) e de CTLA-4 em modular a produção de IFN-. Observamos que a intensidade da resposta Th1 na leishmaniose mucosa está associada com o aumento do número de células T efetoras ativadas. E que, a modulação não apropriada dessas células e a manutenção de uma resposta inflamatória persistente leva ao dano tecidual observado na leishmaniose mucosa. Portanto, os resultados aqui apresentados contribuíram nas questões relacionadas aos aspectos imunológicos em grupos de pacientes com leishmaniose visceral, leishmaniose cutânea e leishmaniose mucosa no que se refere ao diagnóstico sorológico e modulação da resposta imune.CAPES; NIH – grant AI-3063

Comparative analysis of the tissue inflammatory response in human cutaneous and disseminated leishmaniasis

Cutaneous leishmaniasis (CL) is the most frequent clinical form of tegumentary leishmaniasis and is characterised by a single or a few ulcerated skin lesions that may disseminate into multiple ulcers and papules, which characterise disseminated leishmaniasis (DL). In this study, cells were quantified using immunohistochemistry and haematoxylin and eosin staining (CD4+, CD68+, CD20+, plasma cells and neutrophils) and histopathology was used to determine the level of inflammation in biopsies from patients with early CL, late CL and DL (ulcers and papules). The histopathology showed differences in the epidermis between the papules and ulcers from DL. An analysis of the cells present in the tissues showed similarities between the ulcers from localised CL (LCL) and DL. The papules had fewer CD4+ T cells than the DL ulcers. Although both CD4+ cells and macrophages contribute to inflammation in early CL, macrophages are the primary cell type associated with inflammation intensity in late ulcers. The higher frequency of CD20+ cells and plasma cells in lesions demonstrates the importance of B cells in the pathogenesis of leishmaniasis. The number of neutrophils was the same in all of the analysed groups. A comparison between the ulcers from LCL and DL and the early ulcers and papules shows that few differences between these two clinical forms can be distinguished by observing only the tissue

CD8+ T cells in situ in different clinical forms of human cutaneous leishmaniasis.

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2014-06-04T12:35:44Z No. of bitstreams: 1 Dantas ML CD8+ T cells in situ ....pdf: 2478160 bytes, checksum: ff70ece107c21adcef550b94d28d6b52 (MD5)Made available in DSpace on 2014-06-04T12:35:44Z (GMT). No. of bitstreams: 1 Dantas ML CD8+ T cells in situ ....pdf: 2478160 bytes, checksum: ff70ece107c21adcef550b94d28d6b52 (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório Avançado de Saúde Pública. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório Avançado de Saúde Pública. Salvador, BA, BrasilHospital Universitário Professor Edgard Santos. Universidade Federal da Bahia. Serviço de Imunologia. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais Conselho Nacional de Desenvolvimento Científico e Tecnológico. Salvador, BA, BrasilHospital Universitário Professor Edgard Santos. Universidade Federal da Bahia. Serviço de Imunologia. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais Conselho Nacional de Desenvolvimento Científico e Tecnológico. Salvador, BA, BrasilHospital Universitário Professor Edgard Santos. Universidade Federal da Bahia. Serviço de Imunologia. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais Conselho Nacional de Desenvolvimento Científico e Tecnológico. Salvador, BA, BrasilHospital Universitário Professor Edgard Santos. Universidade Federal da Bahia. Serviço de Imunologia. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais Conselho Nacional de Desenvolvimento Científico e Tecnológico. Salvador, BA, BrasilHospital Universitário Professor Edgard Santos. Universidade Federal da Bahia. Serviço de Imunologia. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais Conselho Nacional de Desenvolvimento Científico e Tecnológico. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório Avançado de Saúde Pública. Salvador, BA, BrasilIntroduction: Leishmania braziliensis infection induces a large spectrum of lesions that clinically manifest as nodules or papules that progress to ulcers. Although it is already known that T helper cells predominate in the lesions, cytotoxic T cells have also been reported to be present, and their role in leishmaniasis immunopathogenesis is not well known. This study investigated the amounts of CD8+ and granzyme B+ cells in different clinical forms of human cutaneous leishmaniasis (CL). Methods: Forty tissue fragments from early (E-CL) and late CL (L-CL) lesions and from disseminated leishmaniasis (DL) - papules and ulcers - were characterized. The infl amed area per fragment was calculated, and the CD8 and granzyme B expression levels in the infi ltrates were quantifi ed by counting positive cells in 15 fi elds. The localization of CD8 and granzyme B was graded subjectively. Results: Infl ammation was higher in L-CL and DL ulcers. CD8 expression was increased in late ulcerated lesions compared to recent lesions. The increase in CD8+ cells also correlated with the duration of the lesion. Papules had a higher frequency of granzyme B+ cells than E-CL lesions, although the frequency was similar to those for late and DL ulcers. CD8+ cells were mostly found in the papillary dermis. Conclusions: CD8+ T and granzyme B+ cells are present in the infl ammatory infi ltrates of CL and DL and may participate in the immunopathogenesis of Leishmania infection

Revista da Sociedade Brasileira de Medicina Tropical

p. 728-734Introduction: Leishmania braziliensis infection induces a large spectrum of lesions that clinically manifest as nodules or papules that progress to ulcers. Although it is already known that T helper cells predominate in the lesions, cytotoxic T cells have also been reported to be present, and their role in leishmaniasis immunopathogenesis is not well known. This study investigated the amounts of CD8+ and granzyme B+ cells in different clinical forms of human cutaneous leishmaniasis (CL). Methods: Forty tissue fragments from early (E-CL) and late CL (L-CL) lesions and from disseminated leishmaniasis (DL) - papules and ulcers - were characterized. The inflamed area per fragment was calculated, and the CD8 and granzyme B expression levels in the infiltrates were quantified by counting positive cells in 15 fields. The localization of CD8 and granzyme B was graded subjectively. Results: Inflammation was higher in L-CL and DL ulcers. CD8 expression was increased in late ulcerated lesions compared to recent lesions. The increase in CD8+ cells also correlated with the duration of the lesion. Papules had a higher frequency of granzyme B+ cells than E-CL lesions, although the frequency was similar to those for late and DL ulcers. CD8+ cells were mostly found in the papillary dermis. Conclusions: CD8+ T and granzyme B+ cells are present in the inflammatory infiltrates of CL and DL and may participate in the immunopathogenesis of Leishmania infection

Comparative analysis of the tissue inflammatory response in human cutaneous and disseminated leishmaniasis

Cutaneous leishmaniasis (CL) is the most frequent clinical form of tegumentary leishmaniasis and is characterised by a single or a few ulcerated skin lesions that may disseminate into multiple ulcers and papules, which characterise disseminated leishmaniasis (DL). In this study, cells were quantified using immunohistochemistry and haematoxylin and eosin staining (CD4+, CD68+, CD20+, plasma cells and neutrophils) and histopathology was used to determine the level of inflammation in biopsies from patients with early CL, late CL and DL (ulcers and papules). The histopathology showed differences in the epidermis between the papules and ulcers from DL. An analysis of the cells present in the tissues showed similarities between the ulcers from localised CL (LCL) and DL. The papules had fewer CD4+ T cells than the DL ulcers. Although both CD4+ cells and macrophages contribute to inflammation in early CL, macrophages are the primary cell type associated with inflammation intensity in late ulcers. The higher frequency of CD20+ cells and plasma cells in lesions demonstrates the importance of B cells in the pathogenesis of leishmaniasis. The number of neutrophils was the same in all of the analysed groups. A comparison between the ulcers from LCL and DL and the early ulcers and papules shows that few differences between these two clinical forms can be distinguished by observing only the tissue