CELL ADHESION DISORDERS IN THE EPIDERMIS

我们将确定表皮黏附蛋白的缺陷是如何 基本的 细胞抑制与基底膜(BM)的附着和 附着力- 依赖细胞功能(S)。有了这个目标，我们确定了 粘合剂 BM配基层粘连蛋白5(外膜蛋白)的克隆及序列分析 LAMA3 编码层粘连蛋白5的α3链的基因 与以下内容交互 基底细胞中的两种整合素黏附受体，α6β4 半桥粒(HDs)在体内平衡组织中介导锚定和 使用 整合素α3beta1控制伤口中的细胞迁移。十字 谈一谈 在这两个黏附系统之间平衡两个细胞的需求 锚地 伤口的动态平衡和动态平衡。严重起泡 上皮组织 由HDs的不完全形成和缺陷引起 在……里面 层粘连蛋白5在重型结缔组织病患者中的表达 表皮松解症 大疱病(Jeb)。层粘连蛋白5的表达缺陷，如JEB， 应该 扰乱黏附依赖的上皮细胞功能 起水泡的 上皮细胞。我们希望通过以下方法构建人类Jeb的小鼠模型 利用同源基因靶向阻断LAMA3基因 重组。至 避免胚胎或新生儿死亡，我们将构建一个乳糜液 小白鼠 来自野生型小鼠囊胚和纯合子的ES细胞 基因突变 LAMA3基因或通过调节诱导物下的突变 推动者。由此产生的食糜动物将表达出两种野生的 类型和 有缺陷的BM进入成年期允许研究 粘附性依赖 在(I)调节增殖和分化方面的作用， (Ii) 减少锚定和运动之间的串扰，从而 细胞侵袭增加，(Iii)检测T细胞的系统 与T细胞淋巴瘤和移植物相关的表皮趋向性 宿主 疾病。

We will determine how defects in adhesion proteins of epidermal basal cells inhibit both attachment to the basement membrane (BM) and adhesion- dependent cell function(s). With this goal, we identified the adhesive BM ligand laminin 5 (epiligrin) and sequenced cDNA products of the LAMA3 gene that encode the alpha3 chain of laminin 5. Laminin 5 interacts with two integrin adhesion receptors in basal cells, alpha6beta4 in hemidesmosomes (HDs) to mediate anchorage in homeostatic tissue and with integrin alpha3beta1 to control cell migration in wounds. Cross talk between these two adhesion systems balance needs for both cell anchorage in homeostasis and motility in wounds. Severe blistering of epithelium results from incomplete formation of HDs and is caused by defects in laminin 5 in patients with the gravis form of junctional epidermolysis bullosis (JEB). Defects in expression of laminin 5, as in JEB, should disrupt the adhesion-dependent epithelial functions beyond blistering of the epithelia. We wish to construct a mouse model for human JEB by targeted disruption of the LAMA3 gene using homologous recombination. To avoid embryonic or neonatal lethality we will construct a chymeric mouse from wild type mouse blastocyts and ES cells homozygous for mutations in the LAMA3 gene or by regulation of the mutations under an inducible promoter. The resulting chymeric animals will express both wild type and defective BM into adulthood permitting studies on adhesion-dependent functions on (i) in regulating proliferation and differentiation, (ii) decreased cross talk between anchorage and motility with resulting increased cell invasion, (iii) a system for examining T cell epidermotropism associated with T cell lymphoma and graft verses host disease.