酯多糖：朋友還是敵人？

Lipopolysaccharide: friend or foe?

酯多醣（內毒素）是革蘭氏陰性菌細胞壁的主要成分。酯多醣長久以來被認為與促進發炎及引起敗血症有密切關聯。然而研究指出某些內毒素亦促進甚或不影響發炎反應。不同來源之內毒素因此顯現不同層次的免疫調控現象。結構變異可能為導致此現象之原因。本評論主要探討內毒素結構變異與不同程度免疫調控之關聯，並指出變化內毒素結構組成可用於預防甚或治療慢性發炎相關疾病。

Lipopolysaccharides (LPS) are lipid-polysaccharide complexes found in the outer membrane of Gram-negative bacteria. They are well known for inducing a strong immune response and may lead to septic shock in animals and humans. The structure and chemical properties of LPS vary among Gram-negative bacteria and some LPS molecules actually inhibit the activity of immune cells. In this mini-review, we summarize the mechanisms underlying the immuno-modulatory properties of LPS isolated from various bacterial species. We also address the possibility of using bacterial or engineered LPS for the treatment of inflammatory diseases.