THE A(1,3)FUCOSYLTRANSFERASE GENES AND SELECTIN LIGAND EXPRESSION

选择依赖的粘附事件在免疫介导的病原体处置中为白细胞贩运提供了重要的贡献。选择素依赖的粘附也可能有助于将自然杀伤细胞（NK）和其他免疫细胞递送到肿瘤，从而促进NK细胞依赖的体内癌细胞消除。选择素-选择素拮抗剂偶联也可能控制骨髓细胞的生长和分化，因为选择素配体缺陷与异常骨髓细胞增殖有关。α(1,3)聚焦转移酶Fuc-TIV和Fuc-TVII催化聚焦化事件，对活性选择配体的形成至关重要。这些酶因此处于控制白细胞运输事件和髓细胞增殖过程的位置。为了更全面地了解这两种酶如何促进(i)选择素对抗受体的合成、活性和结构，（ii）髓细胞增殖，（iii）白细胞运输，提出了四个特定的目标。特异性目标#1将定义高内皮小静脉和白细胞中由Fuc-TIV和Fuc-TVII催化合成的聚糖的结构。这项工作将使用放射性标记的单糖，以及在选择素配体的集中化和相应的选择素配体活性缺陷方面存在结构性或条件性缺陷的突变小鼠菌株（与Minora Fukuda博士合作，项目一）。特异性Aim #II将定义在髓系分化过程中f - tvii的表达模式，以及E-和p -选择素配体的活性，开始了解在缺乏选择素配体活性的情况下在髓系谱系中观察到的异常增殖，使用已安装绿色荧光蛋白基因的小鼠鉴定骨髓源性髓系祖细胞，并在f - tvii位点的控制下表达。特异性Aim #III将探索Fuc TVII与β (1,4) GalNAc转移酶之间的合成相互作用，这种相互作用可能会改变T淋巴细胞谱系中选择素配体的结构和活性。本研究将在β (1,4)GalNAc基因座缺失的小鼠，以及在β (1,4)GalNAc基因座的控制下安装蓝色荧光蛋白基因的小鼠中完成。聚糖结构分析将补充这些研究（与Minoru Fukuda博士合作，项目一）。特异性Aim #IV将确定选择素配体和其他粘附分子在NK细胞体外和体内杀死癌细胞、体内运输到肿瘤以及体内抑制肿瘤生长的能力中的作用。

Selectin-dependent adhesive events provide essential contributions to leukocyte trafficking in immune-mediated disposition of pathogens. Selectin-dependent adhesion may also contribute to delivery of natural killer (NK) cells and other immune cells to tumors, and may thereby facilitate NK cell-dependent elimination of cancer cells in vivo. The selectin-selectin counter-receptor couple may also control cell growth and differentiation in the marrow, since selectin ligand deficiencies are associated with aberrant myeloid cell proliferation. The alpha (1,3) fucosyltransferases Fuc-TIV and Fuc-TVII catalyze fucosylation events essential to the elaboration of active selecting ligands. These enzymes are thus in a position to control leukocyte trafficking events, and myeloid proliferation processes. To more completely understand the molecular of how these two enzymes contribute to (i) selectin counter-receptor synthesis, activity, and structure, (ii) myeloid cell proliferation, and (iii) leukocyte trafficking, four specific aims are proposed. Specific Aim #1 will define the structures of the glycans whose synthesis is catalyzed by Fuc-TIV and Fuc-TVII, in high endothelial venules, and in leukocytes. This work will use radiolabeled monosaccharides, and strains of mutant mice with constitutive or conditional defects in fucosylation of selectin ligands and corresponding defects in selectin ligand activity (collaboration with Dr. Minora Fukuda, Project I). Specific Aim #II will define the expression patterns of Fuc-TVII, and E- and P-selectin ligand activities, during myeloid differentiation, to begin to understand the aberrant proliferation observed in the myeloid lineage in the absence of selectin ligand activity Fuc TVII-expressing, marrow-derived myeloid progenitors will be identified using mice where the green fluorescence protein gene has been installed within, and is expressed under the control of the Fuc-TVII locus. Specific Aim #III will explore a synthetic interaction between Fuc TVII and a beta (1,4) GalNAc transferase that may modify selectin ligand structure and activity in the T lymphocyte lineage. These studies will be completed using mice deleted for the beta (1,4)GalNAc locus, and using mice where the blue fluorescence protein gene has been installed within, and is expressed control the control of the beta (1,4)GalNAc locus. Glycan structural analyses will complement these studies (collaboration with Dr. Minoru Fukuda, Project I). Specific Aim #IV will determine the role of selectin ligands, and other adhesion molecules, in the ability of NK cells to kill cancer cell in vitro and in vivo, to traffic to tumors in vivo, and to suppress tumor growth in vivo.