HETEROGENEITY IN P-GLYCOPROTEIN (MULTIDRUG-RESISTANCE) ACTIVITY AMONG MURINE PERIPHERAL T-CELLS - CORRELATION WITH SURFACE PHENOTYPE AND EFFECTOR FUNCTION
HETEROGENEITY IN P-GLYCOPROTEIN (MULTIDRUG-RESISTANCE) ACTIVITY AMONG MURINE PERIPHERAL T-CELLS - CORRELATION WITH SURFACE PHENOTYPE AND EFFECTOR FUNCTION
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DOI：
10.1002/eji.1830241208
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发表时间：
1994-12-01
影响因子：
5.4
通讯作者：
MACDONALD, HR
中科院分区：
文献类型：
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作者：
BOMMHARDT, U;CEROTTINI, JC;MACDONALD, HR
P - 糖蛋白（P - gly）是一种跨膜外排泵，负责肿瘤细胞的多药耐药性。利用荧光染料罗丹明123（Rh123）可以通过微量荧光法方便地评估P - gly的功能活性，罗丹明123是P - gly转运体的一种人工底物。在此我们利用Rh123外排试验评估小鼠外周T淋巴细胞亚群中的P - gly活性。我们的数据表明，几乎所有的CD8(+)细胞都能有效地外排Rh123，而只有一部分CD4(+)细胞表现出P - gly活性。CD4(+)细胞中P - gly活性与一组表面标志物表达的相关性显示，具有“活化/记忆”表型（CD45RB(-)、CD44(hi)、CD62L(-)、CD25(+)、CD69(+)）的细胞仅存在于能够外排Rh123的组分中。相比之下，“初始”表型的CD4(+)细胞（CD45RB(+)、CD44(lo)、CD62L(+)、CD25(-)、CD69(-)）根据P - gly活性可进一步细分为两个主要亚群。在对分选细胞群的功能研究中，当受到多种多克隆刺激激活时，“初始”CD4(+)细胞中能够外排Rh123的亚群比保留Rh123的对应亚群增殖更强烈，并且分泌更高水平的白细胞介素（IL）- 2。此外，该亚群在刺激时可产生可检测水平的干扰素（IFN）-γ，但不产生IL - 4或IL - 10。正如预期的那样，保留Rh123的“初始”亚群在刺激后仅产生IL - 2，而“记忆”亚群除了产生低水平的IL - 2外，还产生IFN -γ、IL - 4和IL - 10。总之，我们的数据表明，P - gly活性是一个新的参数，可用于区分一部分基于表面表型会被视为初始的“预活化”CD4(+)细胞。
P-glycoprotein (P-gly) is the transmembrane efflux pump responsible for multidrug resistance in tumor cells. Functional P-gly activity can be conveniently assessed microfluorometrically using the fluorescent dye rhodamine 123 (Rh123), which is an artificial substrate for the P-gly transporter. Here we assess P-gly activity in subsets of mouse peripheral Tlymphocytes using the Rh123 efflux assay. Our data indicate that virtually all CD8(+) cells extrude Rh123 efficiently, whereas only a subset of CD4(+) cells exhibit P-gly activity. Correlation of P-gly activity in CD4(+) cells with the expression of a panel of surface markers revealed that cells bearing an ''activated/memory'' phenotype (CD45RB(-), CD44(hi), CD 62L(-), CD25(+), CD69(+)) were exclusively found in the fraction that can extrude Rh123. In contrast ''naive'' phenotype CD4(+) cells (CD45RB(+), CD44(lo), CD62L(+), CD25(-), CD69(-)) could be further subdivided into two major subsets based on P-gly activity. In functional studies of sorted cell populations the Rh123-extruding subset of ''naive'' CD4(+) cells proliferated more strongly and secreted higher levels of interleukin (IL)-2 than its Rh123-retaining counterpart when activated by a variety of polyclonal stimuli. Furthermore, this subset produced detectable levels of interferon (IFN)-gamma upon stimulation but no IL-4 or IL-10. As expected, the Rh123-retaining ''naive'' subset produced only IL-2 after stimulation,whereas the ''memory'' subset produced IFN-gamma, IL-4 and IL-10 in addition to low levels of IL-2. Collectively, our data indicate that P-gly activity is a novel parameter that can be used to distinguish a subset of ''preactivated'' CD4(+) cells that would be considered as naive on the basis of their surface phenotype.