ANALYSIS OF DENDRITIC CELL LEUKOCYTE COMMON ANTIGEN

人类白细胞共同抗原（LCA）由一个家族组成， 五种一级结构不同的跨膜糖蛋白 依赖于来自单个基因的mRNA转录物的选择性剪接。 LCA 所有白细胞亚群表达和存在同源LCA 几种动物物种之间的分子表明一个重要的， 白细胞生物学中进化保守的作用，可能与 所有涉及白细胞的疾病 更具体地说， 有证据表明LCA蛋白代表一组细胞表面受体 蛋白酪氨酸磷酸酶活性参与信号传导 转导并在淋巴增殖、分化和 细胞毒 这表明他们的研究可能会增强我们对 细胞增殖和分化调控网络， 证明在临床上与感染、过敏性 和自身免疫性疾病、同种异体移植排斥、肿瘤-宿主相互作用和 肿瘤预防 LCAs的详细结构表征 从淋巴亚群中获得;然而， 关于免疫相关的LCA表达的可用信息 从淋巴组织细胞悬浮液中分离的树突状细胞， 外周血 最近，我们进行了表位定位研究， 这强烈表明人类朗格汉斯细胞表达一种新的形式， LCA。 这就提出了相关的哺乳动物树突细胞 也可以表达新的LCA同种型。 我们建议使用双色 免疫分型、免疫沉淀/SDS-PAGE、北方印迹、PCR 扩增，cDNA测序和S1核酸酶保护分析，以研究 免疫相关树突状细胞表达LCA亚型的结构 人类、小鼠和大鼠的细胞。 这些研究将提供信息 关于各种免疫相关树突状细胞与 彼此和其他抗原呈递细胞， 单核细胞/巨噬细胞。 本研究将为今后的研究奠定基础 致力于提高对树突状细胞特异性的抗LCA单克隆抗体， 细胞，并研究细胞转染的功能效应， 不同的LCA cDNA。 反过来，这将使新的免疫研究- 相关的树突状细胞个体发生/分化，并进一步了解 LCA亚型多样性的功能意义。

The human leukocyte common antigen (LCA) consists of a family of at least five transmembrane glycoproteins whose differences in primary structure depend on alternative splicing of mRNA transcripts from a single gene. LCA expression by all leukocyte subsets and the existence of homologous LCA molecules among several animal species suggest an important, evolutionarily-conserved role in leukocyte biology which may be relevant to the entire spectrum of diseases involving leukocytes. More specifically, evidence exists that LCA proteins represent a set of cell surface receptors with protein tyrosine phosphatase activity that are involved in signal transduction and play a role in lymphoid proliferation, differentiation and cytotoxicity. This suggests that their study may enhance our understanding of cell proliferation and differentiation regulatory networks, and may prove to be clinically relevant to the management of infections, allergic and autoimmune disorders, allograft rejection, tumor-host interactions and tumor prevention. The detailed structural characterization of LCAs obtained from lymphoid subsets has been performed; however, there is little information available concerning LCA expression by immune-associated dendritic cells isolated from lymphoid tissue cell suspensions and peripheral blood. Recently, we have performed epitope mapping studies which strongly suggest that human Langerhans cells express a novel form of LCA. This raises the possibility that related mammalian dendritic cells may also express novel LCA isoforms. We propose to use two-color immunophenotyping, immunoprecipitation/SDS-PAGE, Northern blotting, PCR amplification, cDNA sequencing and S1 nuclease protection analysis to study the structure of LCA isoforms expressed by immune-associated dendritic cells in the human, mouse and rat. These studies will provide information concerning the relatedness of various immune-associated dendritic cells to one another and to other antigen-presenting cells such as monocytes/macrophages. This research will be the foundation for future efforts to raise anti-LCA monoclonal antibodies specific for dendritic cells, and to study the functional effects of cell transfection with different LCA cDNAs. This, in turn, will allow novel studies of immune- associated dendritic cell ontogeny/phylogeny and further our understanding of the functional significance of LCA isoform diversity.