Artigo Acesso aberto Produção Nacional Revisado por pares

Characterization of the memory/activated T cells that mediate the long‐lived host response against tuberculosis after bacillus Calmette–Guérin or DNA vaccination

1999; Wiley; Volume: 97; Issue: 4 Linguagem: Inglês

10.1046/j.1365-2567.1999.00840.x

ISSN

1365-2567

Autores

Célio Lopes Silva, Vânia Luiza Deperon Bonato, Valéria Marçal Felix de Lima, Lúcia Helena Faccioli, Sylvia Cardoso Leão,

Tópico(s)

Immune Response and Inflammation

Resumo

The memory/activated T cells, which mediate the long‐lived host response against tuberculosis, in mice immunized with either bacillus Calmette–Guérin (BCG) or mycobacterium heat‐shock protein 65 (hsp 65) antigen expressed from plasmid DNA (DNA‐hsp 65), were characterized. Protection against Mycobacterium tuberculosis challenge by DNA‐hsp 65 vaccination was associated with the presence of lymph node T‐cell populations in which CD8 + /CD44 hi interferon‐γ (IFN‐γ)‐producing/cytotoxic cells were prominent even after 8 or 15 months of plasmid DNA‐mediated immunizations, whereas after BCG vaccination the majority were CD4 + /CD44 lo IFN‐γ‐producing T cells. When the cells were separated into CD4 + CD8 − and CD8 + CD4 − and then into CD44 hi and CD44 lo types, CD44 lo cells were essentially unable to transfer protection in adoptive transfer experiments, the most protective CD44 hi cells were CD8 + CD4 − and those from DNA‐vaccinated mice were much more protective than those from BCG‐immunized mice. The frequency of protective T cells and the level of protection were increased up to 8 months and decreased after 15 months following DNA or BCG immunizations.

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