Gerner Wilhelm, Käser Tobias, Saalmüller Armin
Institute of Immunology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Dev Comp Immunol. 2009 Mar;33(3):310-20. doi: 10.1016/j.dci.2008.06.003. Epub 2008 Jul 2.
Natural killer (NK) cells represent an important cell population of the innate immune system with the ability to attack spontaneously pathogen-infected and malignant body cells as well as to produce immune-regulatory cytokines. T lymphocytes belong to the adaptive immune system and perform a wide array of functions in immune regulation, inflammation and protective immune responses. In this review we summarize the current knowledge about the phenotype and functional characteristics of these two cell populations in swine. Porcine NK cells can be distinguished from T cells by the complex phenotype perforin+ CD3(-)CD4(-)CD5(-)CD6(-)CD8alpha+CD8beta(-)CD11b+CD16+. Investigations so far show that these cells have the capacity to lyse virus-infected target cells and respond to various regulatory cytokines. Such cytokines can induce interferon-gamma (IFN-gamma) production in porcine NK cells, as well as the up-regulation of effector/activation molecules like perforin and CD25. Porcine T cells can be divided into a number of subpopulations, including a prominent fraction of T cells expressing T-cell receptors (TCR) with gammadelta-chains. Like TCR-alphabeta T cells, these TCR-gammadelta T cells can express CD8alpha and MHC class II, two molecules which in swine seem to be correlated with an activation status of T cells. Functional properties of these cells seem to include cytolytic activity as well as antigen presentation; however, both aspects require further investigation. Like in other species, TCR-alphabeta T cells in swine comprise MHC class-I restricted cytolytic T cells, T-helper cells and recently identified regulatory T cells. We summarize data on the phenotype and function of these cells including memory cell formation. Current knowledge suggests that MHC class-I restricted cytolytic T cells can be identified by the expression of CD8alphabeta heterodimers. T-helper cells express CD4 as well as other activation-related markers, including CD8alpha, MHC class II and CD45RC. Porcine regulatory T cells have a phenotype similar to that of mouse and humans: CD4+CD25+Foxp3+. First results indicate that these cells can suppress proliferation of other T cells and produce IL-10. Finally, the abundant expression of swine-specific activation markers CD8alpha and MHC class II on T cells and NK cells is discussed in more detail.
自然杀伤（NK）细胞是先天性免疫系统的重要细胞群体，能够自发攻击病原体感染的细胞和恶性体细胞，并产生免疫调节细胞因子。T淋巴细胞属于适应性免疫系统，在免疫调节、炎症和保护性免疫反应中发挥多种功能。在这篇综述中，我们总结了目前关于猪体内这两种细胞群体的表型和功能特征的知识。猪NK细胞可通过复杂的表型穿孔素+CD3(-)CD4(-)CD5(-)CD6(-)CD8α+CD8β(-)CD11b+CD16+与T细胞区分开来。目前的研究表明，这些细胞具有裂解病毒感染靶细胞的能力，并能对各种调节性细胞因子作出反应。此类细胞因子可诱导猪NK细胞产生干扰素-γ（IFN-γ），以及上调穿孔素和CD25等效应/激活分子。猪T细胞可分为多个亚群，包括表达γδ链T细胞受体（TCR）的大量T细胞。与TCRαβ T细胞一样，这些TCRγδ T细胞可表达CD8α和MHC II类分子，在猪中这两种分子似乎与T细胞的激活状态相关。这些细胞的功能特性似乎包括细胞溶解活性以及抗原呈递；然而，这两个方面都需要进一步研究。与其他物种一样，猪的TCRαβ T细胞包括MHC I类限制性细胞毒性T细胞、辅助性T细胞以及最近发现的调节性T细胞。我们总结了关于这些细胞的表型和功能的数据，包括记忆细胞的形成。目前的知识表明，MHC I类限制性细胞毒性T细胞可通过CD8αβ异二聚体的表达来识别。辅助性T细胞表达CD4以及其他与激活相关的标志物，包括CD8α、MHC II类分子和CD45RC。猪调节性T细胞的表型与小鼠和人类相似：CD4+CD25+Foxp3+。初步结果表明，这些细胞可抑制其他T细胞的增殖并产生IL-10。最后，我们更详细地讨论了猪特异性激活标志物CD8α和MHC II类分子在T细胞和NK细胞上的大量表达。
