Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah 84112-5820, United States.
Mol Pharm. 2011 Dec 5;8(6):2465-75. doi: 10.1021/mp2002957. Epub 2011 Sep 26.
Lectins derived from plant and microbial sources constitute a vital class of entry inhibitors that target the oligomannose residues on the HIV envelope gp120. Despite their potency and specificity, success of lectin-based entry inhibitors may be impeded by high manufacturing costs, formulation and potential mitogenicity. Therefore, there exists a gap in the HIV microbicides pipeline that underscores the need for mass producible, synthetic, broad-spectrum, and biocomptabile inhibitors of HIV entry. Here, we present the development of a polymeric synthetic lectin, based on benzoboroxole (BzB), which exhibits weak affinity (∼25 M(-1)) for nonreducing sugars, similar to those found on the HIV envelope. High molecular weight BzB-functionalized polymers demonstrated antiviral activity that increased with an increase in ligand density and molecular weight of the polymer construct, revealing that polyvalency improves activity. Polymers showed significant increase in activity from 25 to 75 mol % BzB functionalization with EC(50) of 15 μM and 15 nM, respectively. A further increase in mole functionalization to 90% resulted in an increase of the EC(50) (59 ± 5 nM). An increase in molecular weight of the polymer at 50 mol % BzB functionalization showed a gradual but significant increase in antiviral activity, with the highest activity seen with the 382 kDa polymer (EC(50) of 1.1 ± 0.5 nM in CEM cells and 11 ± 3 nM in TZM-bl cells). Supplementing the polymer backbone with 10 mol % sulfonic acid not only increased the aqueous solubility of the polymers by at least 50-fold but also demonstrated a synergistic increase in anti-HIV activity (4.0 ± 1.5 nM in TZM-bl cells), possibly due to electrostatic interactions between the negatively charged polymer backbone and the positively charged V3-loop in the gp120. The benzoboroxole-sulfonic acid copolymers showed no decrease in activity in the presence of a seminal concentration of fructose (p > 0.05). Additionally, the copolymers exhibit minimal, if any, effect on the cellular viability, barrier properties, or cytokine levels in human reconstructed ectocervical tissue after 3 days of repeated exposure and did not show pronounced activity against a variety of other RNA and DNA viruses.
从植物和微生物来源中提取的凝集素构成了一类重要的进入抑制剂，这些抑制剂的作用靶点是 HIV 包膜 gp120 上的寡甘露糖残基。尽管这些抑制剂具有很强的效力和特异性，但由于生产成本高、制剂和潜在的有丝分裂原性，基于凝集素的进入抑制剂的成功可能会受到阻碍。因此，HIV 微抑制剂管道中存在一个空白，这突显了需要大量生产、合成、广谱和生物相容的 HIV 进入抑制剂。在这里，我们提出了一种基于苯并硼杂环（BzB）的聚合合成凝集素的开发，该凝集素对非还原糖的亲和力较弱（∼25 M（-1）），类似于 HIV 包膜上的那些糖。高分子量的 BzB 功能化聚合物表现出抗病毒活性，随着配体密度和聚合物构建物分子量的增加而增加，表明多价性可提高活性。聚合物的活性从 25%增加到 75%的 BzB 功能化，EC（50）分别为 15 μM 和 15 nM。摩尔功能化进一步增加到 90%，导致 EC（50）增加（59±5 nM）。在 50% BzB 功能化的聚合物中增加分子量会导致抗病毒活性逐渐但显著增加，在分子量最高的 382 kDa 聚合物中观察到最高活性（CEM 细胞中的 EC（50）为 1.1±0.5 nM，TZM-bl 细胞中的 EC（50）为 11±3 nM）。在聚合物主链中添加 10 mol%磺酸不仅将聚合物的水溶性提高了至少 50 倍，而且还表现出协同增加抗 HIV 活性（TZM-bl 细胞中的 4.0±1.5 nM），这可能是由于聚合物主链带负电荷与 gp120 中的正电荷 V3 环之间的静电相互作用。在存在精液浓度的果糖的情况下，苯并硼杂环-磺酸共聚物的活性没有降低（p>0.05）。此外，在重复暴露 3 天后，这些共聚物对人重建的外宫颈组织的细胞活力、屏障特性或细胞因子水平几乎没有影响，如果有影响的话，也没有表现出对多种其他 RNA 和 DNA 病毒的明显活性。
