Li Ko-Jen, Lu Ming-Chi, Hsieh Song-Chou, Wu Cheng-Han, Yu Hsin-Su, Tsai Chang-Youh, Yu Chia-Li
Department of Internal Medicine, Buddist Tzu-Chi General Hospital Taipei Branch, Taiwan.
J Leukoc Biol. 2006 Aug;80(2):350-8. doi: 10.1189/jlb.1105668. Epub 2006 Jun 12.
It is conceivable that a membrane component(s) is transferred from antigen-presenting cells to T cells after antigenic stimulation. However, it is not clear whether a certain membrane component(s) is transferred from polymorphonuclear neturophils (PMN) to T cells for immunomodulation. In the presence study, we cocultured two of the three autologous cells-PMN, CD4+ T, and red blood cells (RBC)-homotypically or heterotypically for 1 h. Spontaneous membrane exchange between autologous PMN-PMN and PMN-CD4+ T but not between CD4+ T-CD4+ T or RBC-CD4+ T was observed with a confocal microscope. Loss of membrane exchange between two paraformaldehyde-fixed cells suggests that mutual membrane exchange is via cell-cell contact. Different combinations of cellular enzyme-linked immunosorbent assay for measuring the binding between fixed cells and biotinylated cell lysates showed the same tendency. To identify the molecule(s) mediating PMN-CD4+ T binding, we compared the banding of biotinylated PMN lysates and the banding of plain PMN lysate probed by biotinylated CD4+ T lysate in 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We found that a 75- to 80-kDa surface-expressed molecule on PMN exists constantly to mediate PMN-CD4+ T binding. Peptide analysis disclosed that the molecule had 99.8% identity with lactoferrin (LF). The expression of LF on system lupus erythematosis (SLE)-PMN is less than normal PMN. PMN-CD4+ T coculture increased LF expression on CD4+ T. Normal PMN and human milk-derived LF suppressed interferon-gamma (IFN-gamma) but enhanced interleukin (IL)-10 production of anti-CD3+anti-CD28-activated, normal CD4+ T. In contrast, coculture of SLE-PMN and autologous CD4+ T suppressed IFN-gamma and IL-10 production. These results suggest that the surface-expressed LF released from PMN after contact with autologous CD4+ T modulated its T helper cell type 1 (Th1)/Th2 cytokine production. Decreased LF expression on SLE-PMN abnormally modulates Th1/Th2 production by CD4+ T cells.
可以想象，抗原刺激后，膜成分会从抗原呈递细胞转移至T细胞。然而，尚不清楚是否有特定的膜成分从多形核中性粒细胞（PMN）转移至T细胞以进行免疫调节。在本研究中，我们将三种自体细胞（PMN、CD4⁺ T和红细胞（RBC））中的两种进行同型或异型共培养1小时。用共聚焦显微镜观察到自体PMN-PMN和PMN-CD4⁺ T之间存在自发的膜交换，但CD4⁺ T-CD4⁺ T或RBC-CD4⁺ T之间未观察到。两个经多聚甲醛固定的细胞之间膜交换的丧失表明相互的膜交换是通过细胞间接触进行的。用于测量固定细胞与生物素化细胞裂解物之间结合的细胞酶联免疫吸附测定的不同组合显示出相同的趋势。为了鉴定介导PMN-CD4⁺ T结合的分子，我们在10%十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中比较了生物素化PMN裂解物的条带和经生物素化CD4⁺ T裂解物探测的普通PMN裂解物的条带。我们发现PMN上一种75至80 kDa的表面表达分子持续存在以介导PMN-CD4⁺ T结合。肽分析表明该分子与乳铁蛋白（LF）有99.8%的同源性。系统性红斑狼疮（SLE）-PMN上LF的表达低于正常PMN。PMN-CD4⁺ T共培养增加了CD4⁺ T上LF的表达。正常PMN和人乳来源的LF抑制干扰素-γ（IFN-γ），但增强抗CD3+抗CD28激活的正常CD4⁺ T产生白细胞介素（IL）-10。相反，SLE-PMN与自体CD4⁺ T共培养抑制IFN-γ和IL-10的产生。这些结果表明，与自体CD4⁺ T接触后从PMN释放的表面表达的LF调节其辅助性T细胞1型（Th1）/Th2细胞因子的产生。SLE-PMN上LF表达的降低异常调节CD4⁺ T细胞的Th1/Th2产生。
