Synthesis of a Single-Molecule L-Rhamnose-Containing Three-Component Vaccine and Evaluation of Antigenicity in the Presence of Anti-L-Rhamnose Antibodies
Synthesis of a Single-Molecule L-Rhamnose-Containing Three-Component Vaccine and Evaluation of Antigenicity in the Presence of Anti-L-Rhamnose Antibodies
复制标题
DOI：
10.1021/ja107029z
复制
发表时间：
2010-12-08
影响因子：
15
通讯作者：
Sucheck, Steven J.
中科院分区：
文献类型：
--
作者：
Sarkar, Sourav;Lombardo, Steven A.;Sucheck, Steven J.
碳水化合物通常被认为免疫原性差。因此，提高碳水化合物免疫原性的新方法对碳水化合物作为疫苗成分的发展具有重要意义。我们假设l -鼠李糖（Rha）片段与碳水化合物抗原结合会通过抗体依赖的抗原摄取机制增强具有抗Rha抗体的小鼠抗原的抗原性。为了探索这一假设，我们合成了一种单分子三组分疫苗，该疫苗含有GalNAc-O-Thr （Tn）肿瘤特异性抗原、来自脑膜炎奈瑟菌外膜蛋白的20个氨基酸辅助性t细胞表位（YAF）和Rha片段。该疫苗采用基于fmoc的固相肽自动合成方法合成，并经NaOMe短暂处理去乙酰化。用TiterMax Gold或Sigma佐剂系统配制的rhaa -ovalbumin （rhaa -ova）免疫和增强雌性BALB/c小鼠组，持续35天，以确定小鼠产生抗rha滴度的最佳条件。Rha-OVA免疫组的抗rha抗体滴度比对照组高100倍。产生抗rha的小鼠用rhaa -YAF-Tn或YAF-Tn刺激。在1/100的血清稀释下，最初接种rhaa - ova和随后接种rhaa - yaf - tn的小鼠血清中抗tn滴度比未接种rhaa - ova的小鼠增加了2倍。用Rha-YAF-Tn或YAF-Tn引物的细胞进行体外t细胞增殖研究，以检查抗rha抗体和化学修饰在抗原摄取和呈递方面可能存在的差异。在Rha抗体存在的情况下，抗原浓度降低10倍会刺激T细胞的增殖。结果强烈表明，由于抗rha抗体的存在，脾脏中的T细胞呈现较高浓度的Rha-YAF-Tn。
Carbohydrates are generally considered to be poorly immunogenic. Therefore, new approaches for enhancing their immunogenicity are important for the development of carbohydrates as vaccine components. We hypothesized that conjugation of an L-rhamnose (Rha) moiety to a carbohydrate antigen would enhance the antigenicity of the antigen in mice possessing anti-Rha antibodies via an antibody-dependent antigen uptake mechanism. To explore this hypothesis, we synthesized a single-molecule three-component vaccine containing the GalNAc-O-Thr (Tn) tumor-specific antigen, a 20 amino acid helper T-cell epitope (YAF) derived from an outer-membrane protein of Neisseria meningitides, and a Rha moiety. The vaccine was synthesized by automated Fmoc-based solid-phase peptide synthesis and deacetylated by brief treatment with NaOMe. Groups of female BALB/c mice were immunized and boosted with Rha-ovalbumin (Rha-OVA) formulated with either TiterMax Gold or Sigma Adjuvant System for a period of 35 days in order to determine optimal conditions for generating anti-Rha titers in mice. Anti-Rha antibody titers were > 100 fold higher in groups of mice immunized with Rha-OVA than in the control groups. Mice producing anti-Rha were challenged with Rha-YAF-Tn or YAF-Tn. Sera collected from the groups initially immunized with Rha-OVA and later challenged with Rha-YAF-Tn showed a 2-fold increase in anti-Tn titer at 1/100 serum dilution relative to mice not immunized with Rha-OVA. An in vitro T-cell proliferation study using cells primed with either Rha-YAF-Tn or YAF-Tn was done to examine possible differences in antigen uptake and presentation due to anti-Rha antibody and chemical modification. Proliferation of T cells was stimulated by a 10-fold lower antigen concentration in the presence of Rha antibodies. The results strongly suggest that T cells present in the spleen were presented with higher concentrations of Rha-YAF-Tn as a result of the presence of the anti-Rha antibodies.