Campo Vanessa L, Riul Thalita B, Carvalho Ivone, Baruffi Marcelo-Dias
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Av. Café S/N, CEP 14040-903, Ribeirão Preto, SP (Brazil).
Chembiochem. 2014 Jul 7;15(10):1495-507. doi: 10.1002/cbic.201400069. Epub 2014 Jun 11.
This study describes the synthesis of glycopeptides NHAc[βGal]-(Thr)2 -[αGalNAc]-(Thr)2 -[αGlcNAc]-(Thr)2 Gly-OVA (1-OVA) and NHAc[βGal-αGalNAc]-(Thr)3 -[αLacNAc]-(Thr)3 -Gly-OVA (2-OVA) as mimetics of both T. cruzi and tumor mucin glycoproteins. These glycopeptides were obtained by solid-phase synthesis, which involved the prior preparation of the protected glycosyl amino acids αGlcNAc-ThrOH (3), αGalNAc-ThrOH (4), βGal-ThrOH (5), αLacNAc-ThrOH (6), and βGal-αGalNAc-ThrOH (7) through glycosylation reactions. Immunizations of mice with glycopeptides 1-OVA and 2-OVA induced high antibody titers (1:16 000), as verified by ELISA tests, whereas flow cytometry assays showed the capacity of the obtained anti-glycopeptides 1-OVA and 2-OVA antibodies to recognize both T. cruzi and MCF-7 tumor cells. In addition, antisera induced by glycopeptides 1-OVA and 2-OVA were also able to inhibit T. cruzi fibroblast cell invasion (70 %) and to induce antibody-mediated cellular cytotoxicity (ADCC) against MCF-7 cells, with 50 % reduction of cell viability.
本研究描述了糖肽NHAc[βGal]-(Thr)2 -[αGalNAc]-(Thr)2 -[αGlcNAc]-(Thr)2 Gly-OVA (1-OVA)和NHAc[βGal-αGalNAc]-(Thr)3 -[αLacNAc]-(Thr)3 -Gly-OVA (2-OVA)的合成，它们作为克氏锥虫和肿瘤粘蛋白糖蛋白的模拟物。这些糖肽通过固相合成获得，该过程涉及通过糖基化反应预先制备保护的糖基氨基酸αGlcNAc-ThrOH (3)、αGalNAc-ThrOH (4)、βGal-ThrOH (5)、αLacNAc-ThrOH (6)和βGal-αGalNAc-ThrOH (7)。用糖肽1-OVA和2-OVA免疫小鼠诱导了高抗体滴度（1:16 000），这通过ELISA试验得到验证，而流式细胞术分析表明所获得的抗糖肽1-OVA和2-OVA抗体能够识别克氏锥虫和MCF-7肿瘤细胞。此外，由糖肽1-OVA和2-OVA诱导的抗血清也能够抑制克氏锥虫对成纤维细胞的侵袭（70%），并诱导针对MCF-7细胞的抗体介导的细胞毒性（ADCC），使细胞活力降低50%。
