Navegando por Palavras-chave "vacinas"

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    Cytotoxic T cell adjuvant effects of three Salmonella enterica flagellins
    (Sociedade Brasileira de Microbiologia, 2008-03-01) Braga, Catarina J.m.; Massis, Liliana M.; Alencar, Bruna C.g. [UNIFESP]; Rodrigues, Mauricio Martins [UNIFESP]; Sbrogio-Almeida, M.e.; Ferreira, Luís Carlos de Souza; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Instituto Butantan Divisião de Produção e Desenvolvimento Tecnológico
    Bacterial flagellins are important virulence-associated factors and strong inducers of inflammatory responses in mammalian hosts. Flagellins have also been investigated as potential vaccine adjuvants, either for induction of humoral or cellular immune responses, to different target antigens. In this study we investigated the adjuvant properties of three Salmonella enterica flagellins types (FliCd, FliCi and FljB) to an ovalbumin-derived CD8+ T cell-restricted epitope (OVA257264). Although mice immunized with the three tested flagellins elicited antigen-specific activated CD8+ T cells, only animals immunized with FliCi and FliCd flagellins admixed with ovalbumin mounted specific in vivo cytotoxic responses to peptide-pulsed target cells. The present results indicate that Salmonella flagellins are endowed with type-specific adjuvant effects toward murine CD8+ T cells, a feature that may impact their use as adjuvants for prophylatic or therapeutic vaccines.
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    Importance of CD8 T cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines
    (Academia Brasileira de Ciências, 2003-12-01) Rodrigues, Mauricio Martins [UNIFESP]; Boscardin, Silvia Beatriz [UNIFESP]; Vasconcelos, Jose Ronnie Carvalho de [UNIFESP]; Hiyane, Meire Ioshie [UNIFESP]; Salay, Gerson [UNIFESP]; Soares, Irene S.; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Obligatory intracellular parasites such as Plasmodium sp, Trypanosoma cruzi, Toxoplasma gondii and Leishmania sp are responsible for the infection of hundreds of millions of individuals every year. These parasites can deliver antigens to the host cell cytoplasm that are presented through MHC class I molecules to protective CD8 T cells. The in vivo priming conditions of specific CD8 T cells during natural infection are largely unknown and remain as an area that has been poorly explored. The antiparasitic mechanisms mediated by CD8 T cells include both interferon-g-dependent and -independent pathways. The fact that CD8 T cells are potent inhibitors of parasitic development prompted many investigators to explore whether induction of these T cells can be a feasible strategy for the development of effective subunit vaccines against these parasitic diseases. Studies performed on experimental models supported the hypothesis that CD8 T cells induced by recombinant viral vectors or DNA vaccines could serve as the basis for human vaccination. Regimens of immunization consisting of two different vectors (heterologous prime-boost) are much more efficient in terms of expansion of protective CD8 T lymphocytes than immunization with a single vector. The results obtained using experimental models have led to clinical vaccination trials that are currently underway.