Nanki T, Lipsky P E
Department of Internal Medicine and Harold C. Simmons Arthritis Research Center, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75235, USA.
Int Immunol. 2000 Dec;12(12):1659-67. doi: 10.1093/intimm/12.12.1659.
Chemokine and chemokine receptor interactions may have important roles in leukocyte migration to specific immune reaction sites. Recently, it has been reported that CXC chemokine receptor (CXCR) 3 and CC chemokine receptor (CCR) 5 were preferentially expressed on T(h)1 cells, and CCR3 and CCR4 were preferentially expressed on T(h)2 cells. To investigate chemokine receptor expression by T(h) subsets in vivo, we analyzed cytokine (IL-2, IL-4 and IFN-gamma) and chemokine receptor (CXCR3, CXCR4, CCR3, CCR4 and CCR5) mRNA expression by individual peripheral CD4(+) memory T cells after short-term stimulation, employing a single-cell RT-PCR method. This ex vivo analysis shows that the frequencies of cells expressing chemokine receptor mRNA were not significantly different between T(h)1 and T(h)2 cells in normal peripheral blood. To assess a potential role of in vivo stimulation, we also analyzed unstimulated rheumatoid arthritis synovial CD4(+) memory T cells. CXCR3, CXCR4, CCR3 and CCR5 expression was detected by individual synovial T cells, but the frequencies of chemokine receptor mRNA were not clearly different between T(h)1 and non-T(h)1 cells defined by expression of IFN-gamma or lymphotoxin-alpha mRNA in all RA patients. These data suggest that chemokine receptor expression does not identify individual memory T cells producing T(h)-defining cytokines and therefore chemokine receptor expression cannot be a marker for T(h)1 or T(h)2 cells in vivo.
趋化因子与趋化因子受体的相互作用可能在白细胞迁移至特定免疫反应部位的过程中发挥重要作用。最近有报道称，CXC趋化因子受体（CXCR）3和CC趋化因子受体（CCR）5在Th1细胞上优先表达，而CCR3和CCR4在Th2细胞上优先表达。为了研究体内Th亚群趋化因子受体的表达情况，我们采用单细胞逆转录-聚合酶链反应（RT-PCR）方法，分析了短期刺激后单个外周血CD4(+)记忆T细胞中细胞因子（白细胞介素-2、白细胞介素-4和干扰素-γ）和趋化因子受体（CXCR3、CXCR4、CCR3、CCR4和CCR5）的mRNA表达。这种体外分析表明，正常外周血中表达趋化因子受体mRNA的细胞频率在Th1细胞和Th2细胞之间没有显著差异。为了评估体内刺激的潜在作用，我们还分析了未经刺激的类风湿性关节炎滑膜CD4(+)记忆T细胞。单个滑膜T细胞检测到CXCR3、CXCR4、CCR3和CCR5的表达，但在所有类风湿性关节炎患者中，根据干扰素-γ或淋巴毒素-α mRNA表达定义的Th1细胞和非Th1细胞之间，趋化因子受体mRNA的频率没有明显差异。这些数据表明，趋化因子受体的表达并不能识别产生Th定义细胞因子的单个记忆T细胞，因此趋化因子受体的表达不能作为体内Th1或Th2细胞的标志物。
