双歧杆菌LTA上调ICAM-1表达及其在LAK抗肿瘤中的作用

目的 探讨双歧杆菌脂磷（ｌｉｐｏｔｅｉｃｈｏｉｃ ａｃｉｄ,ＬＴＡ）作用于ＬｏＶｏ细胞后是否能增强ＬＡＫ对该细胞的识别和杀伤,以及ＩＣＡＭ－１在其中的作用。方法采用ＭＴＴ方法观察了ＬＡＫ对ＬｏＶｏ细胞的识别和杀伤作用,并用流式细胞仪和ＥＬＩＳＡ的方法检测了ＬｏＶｏ细胞表面ＩＣＡＭ－１的表达。结果５０μｇ／ｍｌ ＬＴＡ作用３ｄ,ＬＡＫ对ＬｏＶｏ细胞的粘附率由９．６２％增加到２４．４２％,ＬｏＶｏ细胞

Upregulation of ICAM-1 expression enhances cytotoxic sensitivity of tumor cells to LAK by LTA from bifidobacterium

Objective To investigate whether the recognizing and cytotoxic abilities of LAK can be intensified by bifi-dobacterial lipoteichoic acid(LTA) and the possible role of ICAM-1 in this process. Methods Standard MTT assay was used toevaluate the binding rate and cytotoxic capability of LAK to LoVo cells. Flow cytometric assay and ELISA were used to deter-mine the expression of ICAM-1 on these cells. Results LAK cells bound much easier to LoVo cells with an increase from 9.62% to 24.42% as well as a double increase of the anti-tumor sensitivity of LoVo cells to LAK after challenge with 50 μg/mlLTA of Bifidobacterium bffidum 1101. Compared with the control group,both the percentage of ICAM-1 positive cells and theamount of ICAM-1 expression on LoVo cells were greatly increased directly after the challenge of LTA. Conclusion The pos-sible mechanism of the increase of antitumor activity lies in that Bifidobacterial LTA can intensify the binding and recognizingcapability of LAK to tumor cells by promoting the expression of ICAM-1 on the surface of LoVo cells. The therapeutic effecton intestinal cancer may be enhanced by the combined treatment of bifidobacterial LTA and LAK.