Activation of murine peritoneal macrophages by Streptococcus pneumoniae type II capsular polysaccharide: involvement of CD14-dependent pathway.
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.
Um
S H
SH
Division of Immunopharmacology, College of Pharmacy, Sungkyunkwan University, Suwon city, Kyunggi-do, 440-746 South Korea.
Son
E W
EW
Kim
B O
BO
Moon
E Y
EY
Rhee
D K
DK
Pyo
S
S
D000818:Animals; D016667:Bacterial Capsules / Q000737:chemistry*; D018950:Lipopolysaccharide Receptors / Q000502:physiology*; D008262:Macrophage Activation / Q000187:drug effects*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000502:physiology; D011135:Polysaccharides, Bacterial / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000472:pathogenicity*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
D018950:Lipopolysaccharide Receptors; D011135:Polysaccharides, Bacterial; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide