Bovine herpesvirus (BoHV) types 1 and 5 are two closely related alpha-herpesviruses of cattle with neuroinvasive potential. BoHV-5 causes non-suppurative meningoencephalitis in calve whereas encephalitis caused by BoHV-1 has been occasionally reported. As an initial step to understand the biology of both BoHV types in neural cells, undifferentiated SH-SY5Y human neuroblastoma cells were infected with BoHV-1 strains Cooper and Los Angeles (LA), BoHV-5 strain 97/613 and A663, a BoHV-5/BoHV-1 natural recombinant. Cytopathic effect (CPE) in these cells was evident earlier for BoHV-5 strain 97/613 and CPE progression was slower for BoHV-1, particularly for Cooper strain. Virus antigen was detected as early as 8 h post-infection (hpi) for all strains, with the exception of BoHV-1 Cooper for which antigen expression was detectable by 24 hpi. All strains released detectable infectious virus in the extracellular medium by 8 hpi, confirming that undifferentiated SH-SY5Y cells are fully permissive to BoHV infection. Significantly different extracellular virus titers among the different strains were detected by 24 hpi, with BoHV-5 97/613 reaching the maximal virus production. The lowest extracellular titer was recorded for BoHV-1 Cooper at all the evaluated time-points. BoHV-1 Cooper, BoHV-1 LA and BoHV-5 97/613 had a steady increase in intracellular virus production. The evaluation of lysis plaques formation revealed that BoHV-5 A663 produced the largest plaques followed by BoHV-5 97/613. Both BoHV-1 strains produced smaller plaques when compared with BoHV-5. Despite a slower replicative cycle, strain A663 is more efficient in cell to cell dissemination. Thus, it is evident that BoHV-5 strains have growth advantages in undifferentiated neural cells compared with BoHV-1. This in vitro model might be useful to analyze the neuropathogenic potential of bovine alphaherpesviruses.

牛疱疹病毒（BoHV）1型和5型是具有神经入侵潜能的两种紧密相关的牛α疱疹病毒。BoHV-5引起小牛非化脓性脑膜脑炎，而BoHV-1引起的脑炎偶有报道。作为了解神经细胞中两种BoHV类型生物学的第一步，未分化的SH-SY5Y人成神经细胞瘤细胞感染了BoHV-1菌株Cooper和Los Angeles（LA），BoHV-5菌株97/613和A663，即BoHV -5 / BoHV-1天然重组体。在这些细胞中，BoHV-5菌株97/613的细胞病​​变效应（CPE）较早，而BoHV-1尤其是Cooper菌株的CPE进展较慢。早在所有菌株的感染后8 h（hpi）就检测到病毒抗原，但BoHV-1 Cooper除外，其24 hpi可检测到抗原。所有菌株在8 hpi之前都会在细胞外培养基中释放出可检测的传染性病毒，从而证实未分化的SH-SY5Y细胞完全允许BoHV感染。24 hpi检测到不同菌株之间的细胞外病毒滴度明显不同，BoHV-5 97/613达到了最大的病毒产量。在所有评估的时间点记录了BoHV-1 Cooper的最低细胞外滴度。BoHV-1 Cooper，BoHV-1 LA和BoHV-5 97/613的细胞内病毒产量稳定增加。裂解噬菌斑形成的评估表明，BoHV-5 A663产生的噬菌斑最大，其次是BoHV-5 97/613。与BoHV-5相比，两种BoHV-1菌株均产生较小的噬菌斑。尽管复制周期较慢，但菌株A663在细胞间传播方面更为有效。从而，显然，与BoHV-1相比，BoHV-5菌株在未分化的神经细胞中具有生长优势。这个体外模型可能有助于分析牛α疱疹病毒的神经致病性。