Liang Jing, Han Fucai
The Second Hospital Affiliated to Shanxi Medical University, Taiyuan 030001, China.
Zhongguo Fei Ai Za Zhi. 2009 Jan 20;12(1):59-63. doi: 10.3779/j.issn.1009-3419.2009.01.010.
NKG2D-expressing NK cells and soluble major histocompatibility complex class I-related chain A (sMICA) is one of aroused general interests in tumor research area recently. The aim of the study is to investigate the levels of NKG2D-expressing NK cells and sMICA in peripheral blood of advanced lung cancer which are remarkably related to clinical significance and analyse the role of NKG2D-expressing NK cells and sMICA in immune surveillance.
Flow cytometry was used to determine the percentage of NKG2D-expressing NK cells, T cell subsets, NK cells, and ELISA was used to mesure the levels of sMICA in peripheral blood of 115 advanced lung cancer patients and 50 healthy controls.
Compared with control group, the levels of sMICA, CD8+T cells, NK cells increased, while the levels of NKG2D-expressing NK cells, CD3+ T cells, CD4+ T cells, CD4+ T/CD8+ T in experimental group decreased. NKG2D-expressing NK cells had a perfect negative correlation with sMICA (r =-0.319, P <0.05). NKG2D-expressing NK cells had positive correlation with CD4+ T cells, CD4+ T/CD8+ T and negative correlation with CD8+ T cells (P <0.05), sMICA had negative correlation with CD4+ T cells, CD4+ T/CD8+ T and positive correlation with CD8+ T cells (P <0.05), they had no significant correlation with CD3+ T cells, NK cells respectively (P <0.05).
Accumulation of sMICA in serum may lead to the down-modulation of NKG2D-expressing NK which has been proposed to be a novel mechanism used by cancer cells to evade the tumor immunosurveillance. They may be potential indicators investigating immune functions and helpful in the evaluation of their happening and proceeding.
表达NKG2D的自然杀伤（NK）细胞和可溶性主要组织相容性复合体I类相关链A（sMICA）是近年来肿瘤研究领域引起广泛关注的热点之一。本研究旨在探讨晚期肺癌患者外周血中表达NKG2D的NK细胞和sMICA水平及其与临床意义的相关性，并分析其在免疫监视中的作用。
采用流式细胞术检测115例晚期肺癌患者和50例健康对照外周血中表达NKG2D的NK细胞、T细胞亚群、NK细胞百分比，采用酶联免疫吸附试验（ELISA）检测sMICA水平。
与对照组相比，实验组sMICA、CD8⁺T细胞、NK细胞水平升高，而表达NKG2D的NK细胞、CD3⁺T细胞、CD4⁺T细胞、CD4⁺T/CD8⁺T水平降低。表达NKG2D的NK细胞与sMICA呈显著负相关（r = -0.319，P <0.05）。表达NKG2D的NK细胞与CD4⁺T细胞、CD4⁺T/CD8⁺T呈正相关，与CD8⁺T细胞呈负相关（P <0.05）；sMICA与CD4⁺T细胞、CD4⁺T/CD8⁺T呈负相关，与CD8⁺T细胞呈正相关（P <0.05），它们与CD3⁺T细胞、NK细胞分别无显著相关性（P <0.05）。
血清中sMICA的蓄积可能导致表达NKG2D的NK细胞下调，这可能是癌细胞逃避肿瘤免疫监视的一种新机制。它们可能是研究免疫功能的潜在指标，有助于评估其发生和进展。
