Interaction of host and bacterium in acute infection

1.支原体感染诱导的抗菌肽分析24 h后取小鼠支气管肺泡灌洗液（BALF）。支气管肺泡灌洗液中渗出细胞数量增加，24 h达到峰值，72 h恢复至背景水平。90%的渗出液细胞为多形核白细胞（PMN）。免疫组化染色显示，细胞质中含有抗菌肽CRAMP，CRAMP是cathelicidin家族的成员。pneumoniae，hBD-2 mRNA被诱导表达。此外，在体外实验系统中，hBD-2显示出对M.肺炎2.从M.肺炎支原体A脂蛋白是从肺炎支原体分离的FOF 1型ATP酶的一个亚基B。发现脂蛋白是具有两个棕榈酸酯的双酰化蛋白质。脂蛋白传递的细胞信号依赖于TLR 1、TLR 2和TLR 6。类似地，分离出具有可比能力的三酰化脂蛋白。有趣的是，这些蛋白质的信号传导是TLR 1和TLR 2依赖的. FAM 20是FOF 1型ATP酶a亚基B的一种部分合成的脂肽，可诱导TLR 4-KO小鼠和野生型小鼠腹腔渗出液细胞（PEC）产生TNF-α，但对TLR 2-KO小鼠无此作用，表明这种产生明显依赖于TLR 2。小鼠BALF中TNF-α、IL-6等炎性细胞因子分泌明显。FAM 20诱导炎性细胞因子产生的能力略高于三酰化脂肽。类似地，在BALF中产生趋化因子。特别地，MIP-2早在刺激后数小时就产生。

1. Analysis of anti-microbial peptides induced by mycoplasma infectionMice were intranasally infected with M. pneumoniae and 24 h later the bronchoalveolar lavage fluid (BALF) of the mice were obtained. Number of exudate cells in the BALF was increased with a peak at 24 h and back to the background level at 72 h. 90% of exudate cells was found to be polymorphonuclear leukocyte (PMN). The cells contained antimicrobial peptide CRAMP, a member of cathelicidin family, in cytoplasm, based on immunostaining.When a human airway epithelial cell EBC-1 was treated with heat-inactivated M. pneumoniae, hBD-2 mRNA was induced. Moreover, in vitro in an experimental system, hBD-2 showed antimicrobial activity against M. pneumoniae.2. Purification of lipoproteins, responsible for induction of inflammation, derived from M. pneumoniaeA lipoprotein, a subunit b of FOF1-type ATPase, was isolated from M pneumoniae. The lipoprotein was found to be a diacylated protein with two palmitates. The cell signaling delivered by the lipoprotein was dependent on TLR1, TLR2, and TLR6. Similarly, triacylated lipoproteins with comparable ability were isolated. Interestingly, the signaling by these proteins was TLR1-and TLR2-dependent.3. In vivo induction of inflammation by synthetic lipopeptidesFAM20, a partially synthetic lipopeptide of the a subunit b of FOF1-type ATPase induced the production of TNF-α in peritoneal exudate cells (PEC) of TLR4-KO mice and wild mice, but not TLR2-KO mice, indicating that the production was clearly TLR2-dependent.Subsequently, two different synthetic lipopeptides were administered intranasally to mice. In BALF of the mice, inflammatory cytokines such as TNF-α and IL-6 were markedly secreted. The ability of FAM20 to induce the production of inflammatory cytokines was somewhat higher than that of triacylated lipopeptides. Similarly, chemokines were produced in the BALF. In particular, MIP-2 was produced as early as several hours after stimulation.