PDF(Pubmed)
Abstract：
Equid alphaherpesviruses 1 (EHV-1) and 4 (EHV-4) are closely related and both endemic in horses worldwide. Both viruses replicate in the upper respiratory tract, but EHV-1 may additionally lead to abortion and equine herpesvirus myeloencephalopathy (EHM). We focused on antibody responses in horses against the receptor-binding glycoprotein D of EHV-1 (gD1), which shares a 77% amino acid identity with its counterpart in EHV-4 (gD4). Both antigens give rise to cross-reacting antibodies, including neutralizing antibodies. However, immunity against EHV-4 is not considered protective against EHM. While a diagnostic ELISA to discriminate between EHV-1 and EHV-4 infections is available based on type-specific fragments of glycoprotein G (gG1 and gG4, respectively), the type-specific antibody reaction against gD1 has not yet been sufficiently addressed. Starting from the N-terminus of gD1, we developed luciferase immunoprecipitation system (LIPS) assays, using gD1-fragments of increasing size as antigens, i.e. gD1_83 (comprising the first 83 amino acids), gD1_160, gD1_180, and gD1_402 (the full-length molecule). These assays were then used to analyse panels of horse sera from Switzerland (n = 60) and Iceland (n = 50), the latter of which is considered EHV-1 free. We detected only one true negative horse serum from Iceland, whereas all other sera in both panels were seropositive for both gG4 (ELISA) and gD1 (LIPS against gD1_402). In contrast, seropositivity against gG1 was rather rare (35% Swiss sera; 14% Icelandic sera). Therefore, a high percentage of antibodies against gD1 could be attributed to cross-reaction and due to EHV-4 infections. In contrast, the gD1_83 fragment was able to identify sera with type-specific antibodies against gD1. Interestingly, those sera stemmed almost exclusively from vaccinated horses. Although it is uncertain that the N-terminal epitopes of gD1 addressed in this communication are linked to better protection, we suggest that in future vaccine developments, type-common antigens should be avoided, while a broad range of type-specific antigens should be favored.
摘要：
马疱疹病毒1（EHV-1）和4（EHV-4）密切相关，并且都在全世界的马中流行。两种病毒都在上呼吸道复制,但EHV-1可能额外导致流产和马疱疹病毒性脊髓脑病（EHM）。我们专注于马针对EHV-1（gD1）的受体结合糖蛋白D的抗体反应，与EHV-4（gD4）中的对应物具有77％的氨基酸同一性。两种抗原都会产生交叉反应抗体，包括中和抗体.然而,对EHV-4的免疫不被认为是对EHM的保护。虽然可以根据糖蛋白G的类型特异性片段（分别为gG1和gG4）来区分EHV-1和EHV-4感染的诊断ELISA，针对gD1的类型特异性抗体反应尚未得到充分解决.从gD1的N端开始，我们开发了荧光素酶免疫沉淀系统（LIPS）测定，使用增加大小的gD1片段作为抗原，即gD1_83（包含前83个氨基酸），gD1_160、gD1_180和gD1_402(全长分子)。然后将这些测定用于分析来自瑞士（n=60）和冰岛（n=50）的马血清。后者被认为是无EHV-1。我们只检测到一种来自冰岛的真阴性马血清，而两组中所有其他血清gG4(ELISA)和gD1(LIPS对gD1_402)均为血清阳性。相比之下,gG1的血清阳性相当罕见（35％瑞士血清；14％冰岛血清）。因此,gD1抗体的高百分比可归因于交叉反应和EHV-4感染.相比之下,gD1_83片段能够鉴定具有针对gD1的类型特异性抗体的血清。有趣的是,那些血清几乎完全源于接种疫苗的马。尽管不确定本通讯中提到的gD1的N末端表位是否与更好的保护相关，我们建议在未来的疫苗开发中，应避免常见类型的抗原，而广泛的类型特异性抗原应该是有利的。
