Longevity of duodenal and peripheral T-cell and humoral responses to live-attenuated Salmonella Typhi strain Ty21a.
Vaccine
; 36(31): 4725-4733, 2018 07 25.
Article
em En
| MEDLINE
| ID: mdl-29958737
ABSTRACT
BACKGROUND:
We have previously demonstrated that polyfunctional Ty21a-responsive CD4+ and CD8+ T cells are generated at the duodenal mucosa 18â¯days following vaccination with live-attenuated S. Typhi (Ty21a). The longevity of cellular responses has been assessed in peripheral blood, but persistence of duodenal responses is unknown.METHODS:
We vaccinated eight healthy adults with Ty21a. Peripheral blood and duodenal samples were acquired after a median of 1.5â¯years (ranging from 1.1 to 3.7â¯years) following vaccination. Cellular responses were assessed in peripheral blood and at the duodenal mucosa by flow cytometry. Levels of IgG and IgA were also assessed in peripheral blood by enzyme-linked immunosorbent assay.RESULTS:
No T-cell responses were observed at the duodenal mucosa, but CD4+ T-cell responses to Ty21a and FliC were observed in peripheral blood. Peripheral anti-lipopolysaccharide IgG and IgA responses were also observed. Early immunoglobulin responses were not associated with the persistence of long-term cellular immune responses.CONCLUSIONS:
Early T-cell responses which we have previously observed at the duodenal mucosa 18â¯days following oral vaccination with Ty21a could not be detected at a median of 1.5â¯years. Peripheral responses were observed at this time. Immunoglobulin responses observed shortly after vaccination were not associated with cellular immune responses at 1.5â¯years, suggesting that the persistence of cellular immunity is not associated with the strength of the initial humoral response to vaccination.Palavras-chave
Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Salmonella typhi
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Vacinas Tíficas-Paratíficas
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Linfócitos T
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Imunidade nas Mucosas
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Duodeno
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Imunidade Celular
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article