Mechanism of growth stimulatory effect of vascular endothelial cells by Bartonella henselae.

我们对亨塞巴尔通体刺激血管内皮细胞生长作用的机制进行了研究，得到以下结果：1。B、henselae与人脐静脉内皮细胞（HUVECs）的相互作用：将B.henselae ATCC 49882 （10^7 CFU/ml）与HUVECs共培养，MTT法测定HUVECs的生长情况。与活亨selae共培养的HUVECs增殖呈接种-细菌剂量依赖性，且对血管内皮细胞有特异性的刺激作用。在兔和狗的内皮细胞中也观察到类似的生长促进作用。促进生长的有效成分及机制：紫外光照射或热处理杀死的鸡翅虫使其刺激活性消失，表明这种作用是由活菌的某种作用发挥的，而不仅仅是细菌细胞的存在。为了研究直接接触对大肠杆菌感染的影响，采用Millicell-CM膜过滤法分离了活的亨赛贝氏杆菌。在此条件下，仍能观察到HUVECs的促增殖作用。然而，HUVECs的形态变化与乙肝病毒感染细胞相比不明显。此外，我们还分离出了一株不能附着和进入内皮细胞的无毛的henselae菌株。非梳毛菌株具有与梳毛菌株相同的促HUVECs增殖能力。我们的研究结果表明，蜜蜂可能产生一些血管生成因子(s)并分泌。目前正在进行进一步的研究，以纯化和表征这种血管生成因子。体内实验：将母鸡b .接种于胚胎卵、小鼠和豚鼠的绒毛膜尿囊膜（皮下或皮内接种），动物未见血管生成损伤。

We studied on the mechanism of growth stimulatory effect of vascular endothelial cells by Bartonella henselae, and obtained the following results ;1. Interaction between B, henselae and human umbilical vein endothelial cells (HUVECs) : B.henselae ATCC 49882 (10^7 CFU/ml) was cocultivated with HUVECs, and the growth of HUVECs was estimated by MTT assay. The proliferation of HUVECs cocultivated with live B.henselae was enhanced in inoculated-bacterial dose dependent manner, and the stimulatory effect was specific for vascular endothelial cells. Similar growth enhancement effect was also observed in endothelial cells from rabbits or dogs.2. Active component and mechanism of growth enhancement : B.henselae killed by UV irradiation or heat treatment abolished its stimulatory activity, suggesting that the effect was exhibited by some action of live bacteria, not only by the existence of bacterial cells. To investigate the role of direct contact, live B.henselae were separated from HUVECs by membrane filter (Millicell-CM). Even under this condition, the HUVECs proliferation stimulating effect was observed. However, the morphological changes of HUVECs were not apparent compared to B.henselae infected cells. Furthermore, we isolated a nonpiliated B.henselae strain which was unable to attach to and entry into endothelial cells. The nonpiliated strain possessed the ability to stimulate the proliferation of HUVECs same as piliated strain. Our results suggested that B.henselae might produce some angiogenic factor(s) and secrete it. Further study is currently under way to purify and characterize this angiogenic factor.3. In vivo study : B.henselae was inoculated into chorioallantoic membrane of embryonated eggs, mice and guinea pigs (subcutaneous or intradermal routs), however, no angiogenic lesion was observed in the animals.