干酪乳杆菌LC2W对两种不同胃癌细胞的黏附作用

选取人胃癌细胞株MKN-45和HGC-27,采用形态学观察和显微计数的方法比较菌液浓度、悬浮液、pH值对干酪乳杆菌LC2W(Lactobacillus casei LC2W)黏附细胞的情况。结果表明,LC2W对两种细胞均具有黏附性,对MKN-45的黏附性更强;这种黏附作用具有菌悬液浓度依赖性。当加入的菌悬液浓度达到一定数量时(109 mL-1),平均每个细胞黏附的乳杆菌数量趋于饱和;悬浮介质对Lb.caseiLC2W的黏附性具有明显的影响,其中悬浮于耗尽培养上清液(SCS)的Lb.casei LC2W表现出最好的黏附性;悬浮介质的pH值对Lb.casei LC2W的黏附性也有影响,pH=4.0时黏附性最好。将不同悬浮介质的pH值调整到pH=7.0后,SCS仍能很好的促进LC2W的黏附作用,表明SCS中存在某种促进黏附的物质。由此推测,Lb.casei LC2W对胃癌细胞的黏附机理可能为黏附素与受体的特异性结合。

Adhesion of Lactobacillus casei LC2W to different gastric cell lines

The adhensive ability of Lactobacillus casei LC2W to two gastric cell lines,i.e.MKN-45 and HGC-27,was tested under several variables(bacterial cell concentration,resuspending medium,the pH value of the resuspending solution) via morphological observation and cell counting under microscope.The results showed Lactobacillus casei LC2W was adhensive to both MKN-45 and HGC-27,especially the former.The adhension of Lactobacillus casei LC2W to the gastric cells was concentration-dependent to the lactobacillus cell resuspension,with the average numbers of bacterial cell adhered to per gastric cell increasing tilled the surface of the gastric cells saturated by the lactobacilli cells,when the lactobacilli cell resuspension reached 109cfu per milliliter.While the resuspending solution as well as the pH value of the solution demonstrated significantly effect on the bacterial's adhensive ability,the spent culture supernatant(SCS) of Lactobacillus casei LC2W and pH value 4 were optimal for the lactobacilli cells to adhere to the gastric cells among the resuspending solutions and the serial pH values tested.The adhensive ability of Lactobacillus casei LC2W to MKN-45 was insignificantly affected when the pH value of the SCS was neutralized to pH =7.0,which suggesting some substances in the SCS could promote the lactobacilli cells to the gastric cells.It was proposed that the adhension of Lactobacillus casei LC2W to the gastric cells was mediated by adhensin,which binding to the specific receptors on the mammal cells.