Activation of murine peritoneal macrophages by Streptococcus pneumoniae type II capsular polysaccharide: involvement of CD14-dependent pathway.
Scand J Immunol
; 52(1): 39-45, 2000 Jul.
Article
em En
| MEDLINE
| ID: mdl-10886782
ABSTRACT
In this study we examined the ability of capsular polysaccharide type 2 (PS) from Streptococcus pnemoniae to induce secretory and cellular responses in peritoneal macrophages. Tumour cytotoxicity induced by preincubation with PS was demonstrated to be concentration-dependent. PS-induced tumouricidal activity was partially abrogated by anti-tumour necrosis factor (TNF)-alpha and inhibitor of nitric oxide, whereas anti-interferon (IFN)-alpha/beta antibody and the scavengers of reactive oxygen intermediates had no effect. In addition, supernatants from macrophages treated with PS contained TNF-alpha, and their iNOS-enzymatic activity was significantly increased. Thus, the tumouricidal activity induced by PS appeared to be mediated by the production of TNF-alpha and nitrite. Treatment of macrophages with PS increased the expression of CD14, the receptor for lipolysaccharide (LPS)/LPS-binding protein. Moreover, blocking antibody to CD14 abrogated partially TNF-alpha and nitrite induction by PS, suggesting that the PS-induced CD14 upregulation was correlated with secretion of TNF-alpha and nitrite. Taken together, these results demonstrate that PS may induce macrophage-secretory and cellular activities, in part, possibly via CD14-dependent pathway.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polissacarídeos Bacterianos
/
Streptococcus pneumoniae
/
Cápsulas Bacterianas
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Macrófagos Peritoneais
/
Receptores de Lipopolissacarídeos
/
Ativação de Macrófagos
Limite:
Animals
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article