NOVEL ANGIOGENIC CYTOKINE INDUCED ENDOTHELIAL ANTIGEN

血管生成或新血管生长是诸如动脉粥样硬化、肿瘤生长和类风湿性关节炎（RA）等病症中的重要过程。 我们以前已经证明白细胞介素-8是一种有效的巨噬细胞衍生的血管生成介质（Koch等，Science 258：1798，1992）。 我们还表明，可溶性内皮细胞粘附分子可溶性E-选择素（sE-选择素）和可溶性血管细胞粘附分子-1在诱导血管生成中可以以与细胞因子类似的方式起作用（Koch等人，Nature 376：517，1995）。 我们证明了sE-选择素介导血管生成的机制是通过其内皮配体sialyl-Lewis（sialyl-Lex）。目前，我们专注于一个新的内皮（EC）分子，4A 11，检测单克隆抗体（mAb）4A 11在我们的实验室生产。 该抗原实际上是内皮特异性的，以及内皮选择性的，主要在正常滑膜、淋巴组织、胸腺和皮肤中的EC上表达，表明在细胞归巢至这些区域中可能起作用。 4A 11抗原在体外可由奎宁诱导，在人RA滑膜组织衬里受累关节和人接触性皮炎毒葛模型中上调。 此外，单克隆抗体4A 11检测的抗原包含在Lewisy-6（Ley）和H-5-2（H-2）中。 Ley属于新的碳水化合物家族，其包括唾液酸-Lex，sE-选择素配体，sE-选择素通过其介导血管生成。 我们最近发现可溶性4A 11抗原介导血管生成。 本提案的目的是确定4A 11抗原介导血管生成和参与细胞粘附的机制，以及4A 11抗原在疾病中的作用。我们建议使用体外和体内血管生成测定来确认4A 11抗原的血管生成活性。 我们将确定4A 11抗原是否介导EC粘附分子和EC或白细胞粘附的上调。 我们将描述这种抗原在疾病中的作用。 由于4A 11抗原的合成受岩藻糖基转移酶的调节，我们将研究在岩藻糖基转移酶缺陷的“敲除”小鼠中是否发生血管生成缺陷。 我们将确定这些小鼠是否减少角膜血管生成，伤口修复，其他血管生成介质的表达，或血管生成性关节炎的反应相比，父母的控制。 这些研究应该扩大我们对这种新的血管生成介质的作用模式的理解，这可能会增加我们的能力，以抑制血管生成的条件下，其特征在于持续的新血管形成。

Angiogenesis, or new blood vessel growth, is an important process in conditions such as atherosclerosis, tumor growth, and rheumatoid arthritis (RA). We have shown previously that interleukin-8 is a potent macrophage-derived mediator of angiogenesis (Koch, et al, Science 258: 1798, 1992). We have also shown that soluble endothelial cell adhesion molecules soluble E-selectin (sE-selectin), and soluble vascular cell adhesion molecule-1 can function in a manner similar to cytokines in inducing angiogenesis (Koch, et al, Nature 376:517, 1995). We demonstrated that the mechanism by which sE-selectin mediates angiogenesis is via its endothelial ligand sialyl-Lewis (sialyl-Lex). Currently, we focus on a novel endothelial (EC) molecule, 4A11, detected by monoclonal antibody (mAb) 4A11 produced in our laboratory. This antigen is virtually endothelial-specific, as well as endothelial selective, being expressed mainly on EC in normal synovium, lymphoid tissues, thymus, and skin, suggesting a possible role in cell homing to these areas. The 4A11 antigen is cytokine-inducible in vitro and is upregulated in human RA synovial tissue lining affected joints and in a human poison ivy model of contact dermatitis. Moreover, the antigen detected by monoclonal antibody 4A11 is contained in both Lewisy-6 (Ley) and H-5-2 (H-2). Ley is within the new family of carbohydrates which includes sialyl-Lex, the sE-selectin ligand through which the sE- selectin mediates angiogenesis. We have recently found that the soluble 4A11 antigen mediates angiogenesis. The aim of this proposal is to determine the mechanism by which the 4A11 antigen mediates angiogenesis and participates in cell adhesion, and the role of the 4A11 antigen in disease. We propose to confirm the angiogenic activity of the 4A11 antigen using in vitro and in vivo angiogenesis assays. We will determine whether the 4A11 antigen mediates upregulation of EC adhesion molecules and EC or leukocyte adhesion. We will characterize the role of this antigen in disease. Since the synthesis of the 4A11 antigen is regulated by fucosyltransferases, we will examine whether a defect in angiogenesis occurs in "knockout" mice deficient in fucosyltransferase. We will determine whether these mice have decreased corneal angiogenesis, wound repair, expression of other angiogenic mediators, or angiogenic arthritic responses compared to parental controls. These studies should broaden our understanding of the mode of action of this novel angiogenic mediator which may increase our ability to curb angiogenesis in conditions characterized by persistent neovascularization.