The specific interaction of helper T cells and antigen-presenting B cells. IV. Membrane and cytoskeletal reorganizations in the bound T cell as a function of antigen dose.
The specific interaction of helper T cells and antigen-presenting B cells. IV. Membrane and cytoskeletal reorganizations in the bound T cell as a function of antigen dose.
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DOI：
10.1084/jem.170.5.1697
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发表时间：
1989-11-01
期刊：
影响因子：
--
通讯作者：
Singer SJ
中科院分区：
文献类型：
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作者：
Kupfer A;Singer SJ
用免疫荧光双标记法测定了克隆Th细胞与抗原（Ag）特异性B细胞型APC（B-APC）1：1细胞偶联后LFA-1和CD 4的表面分布、细胞骨架蛋白talin和微管组织中心（MTOC）的胞内分布。Th细胞在IAd的背景下被导向Ag OVA的肽片段。B-APC是转染的A20 B杂交瘤细胞A20-HL，在其表面上具有对半抗原TNP特异性的表面IG，并用不同浓度的DNP-OVA脉冲。在足够高剂量的DNP-OVA（大于100 ng/ml）下，在基本上所有的对中，LFA-1、CD 4和talin各自集中在Th细胞膜上，在此其与B-APC接触，并且Th细胞内的MTOC重新定向以面对接触区域。在较低剂量的DNP-OVA（50和10 ng/ml之间），在所有的夫妇，LFA-1和塔林集中在Th/B-APC接触区，但CD 4聚集的程度，MTOC重新定位，和Th细胞增殖都随着Ag剂量的降低而降低。在没有Ag的情况下，没有观察到这些效应。这些和其他数据表明，两个不同的信号被特异性结合到其B-APC的Th细胞接收。第一个信号，在低Ag剂量，刺激LFA-1和塔林在Th细胞的连接，和一个特定的LFA-1介导的细胞间粘附;第二个信号，在较高的Ag剂量，需要诱导Th细胞增殖，与Th-MTOC重新取向和CD 4聚集相关。
We have used double-immunofluorescence labeling to determine the surface distributions of LFA-1 and CD4, and the intracellular distributions of the cytoskeletal protein talin and of the microtubule organizing center (MTOC) of cloned Th cells in 1:1 cell couples with antigen (Ag)-specific APC of the B cell type (B-APC). The Th cell was directed to a peptide fragment of the Ag OVA in the context of IAd. The B-APC was the transfected A20 B hybridoma cell A20-HL, bearing on its surface a surface Ig specific for the hapten TNP, and pulsed with different concentrations of DNP-OVA. At sufficiently high doses of DNP- OVA (greater than 100 ng/ml), in essentially all couples, LFA-1, CD4, and talin were each concentrated at the Th cell membrane where it was in contact with the B-APC, and the MTOC inside the Th cell was reoriented to face the contact region. At lower doses of DNP-OVA (between 50 and 10 ng/ml), in all couples, LFA-1 and talin were concentrated at the Th/B-APC contact region, but the extent of CD4 clustering, MTOC reorientation, and Th cell proliferation all decreased with decreasing Ag dose. With no Ag, none of these effects was observed. These and other data indicate that two distinct signals are received by the Th cell that is specifically bound to its B-APC. The first signal, at low Ag doses, stimulates a linkage of LFA-1 and talin in the Th cell, and a specific LFA-1-mediated intercellular adhesion; the second signal, at higher Ag doses, is required to induce Th cell proliferation, with which the Th-MTOC reorientation and CD4 clustering are correlated.