Purpose

Acyclovir is most commonly used for treating ocular Herpes Keratitis, a leading cause of infectious blindness. However, emerging resistance to Acyclovir resulting from mutations in the thymidine kinase gene of Herpes Simplex Virus −1 (HSV-1), has prompted the need for new therapeutics directed against a different viral protein. One novel target is the HSV-1 Processivity Factor which is essential for tethering HSV-1 Polymerase to the viral genome to enable long-chain DNA synthesis.

Methods

A series of peptides, based on the crystal structure of the C-terminus of HSV-1 Polymerase, were constructed with hydrocarbon staples to retain their alpha-helical conformation. The stapled peptides were tested for blocking both HSV-1 DNA synthesis and infection. The most effective peptide was further optimized by replacing its negative N-terminus with two hydrophobic valine residues. This di-valine stapled peptide was tested for inhibiting HSV-1 infection of human primary corneal epithelial cells.

Results

The stapled peptides blocked HSV-1 DNA synthesis and HSV-1 infection. The unstapled control peptide had no inhibitory effects. Specificity of the stapled peptides was confirmed by their inabilities to block infection by an unrelated virus. Significantly, the optimized di-valine stapled peptide effectively blocked HSV-1 infection in human primary corneal epithelial cells with selectivity index of 11.6.

Conclusions

Hydrocarbon stapled peptides that simulate the α-helix from the C-terminus of HSV-1 DNA polymerase can specifically block DNA synthesis and infection of HSV-1 in human primary corneal epithelial cells. These stapled peptides provide a foundation for developing a topical therapeutic for treating human ocular Herpes Keratitis.

中文翻译：

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人类原代角膜上皮细胞中的单纯疱疹病毒-1感染被一种针对持续DNA合成的钉合肽阻断

目的

阿昔洛韦最常用于治疗眼部疱疹性角膜炎，这是感染性失明的主要原因。然而，由于单纯疱疹病毒-1 (HSV-1) 胸苷激酶基因突变而出现对阿昔洛韦的耐药性，这促使需要针对不同病毒蛋白的新疗法。一个新的靶标是 HSV-1 加工因子，它对于将 HSV-1 聚合酶束缚到病毒基因组以实现长链 DNA 合成至关重要。

方法

基于 HSV-1 聚合酶 C 末端的晶体结构，用碳氢化合物构建了一系列肽，以保留其 α 螺旋构象。测试了钉合肽阻断 HSV-1 DNA 合成和感染的能力。通过用两个疏水性缬氨酸残基替换其负 N 端，进一步优化了最有效的肽。这种双缬氨酸钉合肽经过测试可抑制人原代角膜上皮细胞的 HSV-1 感染。

结果

钉合肽阻断 HSV-1 DNA 合成和 HSV-1 感染。未钉合的对照肽没有抑制作用。钉合肽的特异性通过其无法阻止不相关病毒的感染而得到证实。值得注意的是，优化后的双缬氨酸钉合肽可有效阻断人原代角膜上皮细胞中的HSV-1感染，选择性指数为11.6。

结论

模拟 HSV-1 DNA 聚合酶 C 端 α 螺旋的碳氢钉合肽可以特异性阻断人原代角膜上皮细胞中的 DNA 合成和 HSV-1 感染。这些钉合肽为开发治疗人眼疱疹性角膜炎的局部治疗剂奠定了基础。