Lambkin Imelda, Pinilla Clemencia, Hamashin Christa, Spindler Lisa, Russell Shannon, Schink Amy, Moya-Castro Rosa, Allicotti Gina, Higgins Lisa, Smith Melanie, Dee Jackie, Wilson Carolyn, Houghten Richard, O'Mahony Daniel
Elan Drug Delivery, Biotechnology Building, Trinity College, Dublin 2, Ireland.
Pharm Res. 2003 Aug;20(8):1258-66. doi: 10.1023/a:1025061317400.
Various lectins bind specifically to oligosaccharides on intestinal cells. Exploiting this specificity, Ulex europaeus agglutinin I (UEA1) has been used as a ligand for targeted oral vaccine delivery to M cells (antigen-presenting cells) in follicle-associated epithelium. In this study we characterized compounds identified from mixture-based positional scanning synthetic combinatorial libraries, which mimic UEA1 and, thus, may have properties applicable to targeted drug delivery.
Two UEA1 mimetics were synthesized and their activity was verified on live cells. The ability of the lead compound, a tetragalloyl D-Lysine amide construct (4-copy gallic acid construct), to deliver dye-loaded polystyrene particles to M cells was assessed in an in situ mouse gut loop model.
The 4-copy gallic acid construct inhibited UEA1 binding to Caco-2 cell membranes with an IC50 of 3 microM, a 650- to 5000-fold increase over the natural UEA1 substrate alpha-L-fucose. The biotin-labeled derivative of this construct demonstrated comparable binding activity as verified on live cells by fluorescence-activated cell sorting. Preclinical studies confirmed its ability to mediate M cell-specific delivery of streptavidin-coated particles in vivo.
Polyphenolic compounds, D-Lysine scaffolds with multiple galloyl groups, can mimic functional activities of UEA1. Properties of such molecules, including low molecular weight, stability, ease of synthesis and low cost, highlight their potential for application in targeted vaccine delivery.
多种凝集素可特异性结合肠道细胞上的寡糖。利用这种特异性，欧洲荆豆凝集素I（UEA1）已被用作配体，用于将靶向口服疫苗递送至滤泡相关上皮中的M细胞（抗原呈递细胞）。在本研究中，我们对从基于混合物的位置扫描合成组合文库中鉴定出的化合物进行了表征，这些化合物模拟UEA1，因此可能具有适用于靶向药物递送的特性。
合成了两种UEA1模拟物，并在活细胞上验证了它们的活性。在原位小鼠肠袢模型中评估了先导化合物四没食子酰-D-赖氨酸酰胺构建体（4拷贝没食子酸构建体）将负载染料的聚苯乙烯颗粒递送至M细胞的能力。
4拷贝没食子酸构建体抑制UEA1与Caco-2细胞膜结合的IC50为3 microM，比天然UEA1底物α-L-岩藻糖高650至5000倍。该构建体的生物素标记衍生物通过荧光激活细胞分选在活细胞上验证显示出可比的结合活性。临床前研究证实了其在体内介导链霉亲和素包被颗粒的M细胞特异性递送的能力。
具有多个没食子酰基的多酚化合物、D-赖氨酸支架可以模拟UEA1的功能活性。这些分子的特性，包括低分子量、稳定性、易于合成和低成本，突出了它们在靶向疫苗递送中的应用潜力。
