Hamamoto Kumiko, Shimizu Takashi, Kida Yutaka, Kuwano Koichi
Department of Bacteriology, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan.
Kurume Med J. 2003;50(3-4):99-107. doi: 10.2739/kurumemedj.50.99.
Cationic peptides are known to play critical roles in innate immunity. The peptides exert not only antimicrobial activity but also suppress the activity of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) by binding to them. We have previously reported that L-peptide, a small linear cationic peptide derived from human granulysin displays broad-spectrum antimicrobial activity. In this study, the in vitro interactions of L-peptide with LPS and LTA were examined. LPS and LTA were found to inhibit the antimicrobial activity of the L-peptide in a dose-dependent manner, and they were shown to bind with the L-peptide. On the other hand, L-peptide failed to inhibit LPS- or LTA-induced cytokine production by macrophages or to block the binding of LPS to the cell surface. Thus, there seems to be a hierarchy that places LPS and LTA above L-peptide in the interactions of L-peptide with LPS and LTA.
已知阳离子肽在先天免疫中发挥关键作用。这些肽不仅具有抗菌活性，还能通过与脂多糖（LPS）和脂磷壁酸（LTA）结合来抑制它们的活性。我们之前报道过，L-肽是一种源自人颗粒溶素的小型线性阳离子肽，具有广谱抗菌活性。在本研究中，检测了L-肽与LPS和LTA的体外相互作用。发现LPS和LTA以剂量依赖性方式抑制L-肽的抗菌活性，并且它们显示出与L-肽结合。另一方面，L-肽未能抑制巨噬细胞中LPS或LTA诱导的细胞因子产生，也未能阻断LPS与细胞表面的结合。因此，在L-肽与LPS和LTA的相互作用中，似乎存在一种等级关系，将LPS和LTA置于L-肽之上。
