Deletion of a Predicted beta-Sheet Domain within the Amino Terminus of Herpes Simplex Virus Glycoprotein K Conserved among Alphaherpesviruses Prevents Virus Entry into Neuronal Axons

作者：Jambunathan Nithya; Charles Anu Susan; Subramanian Ramesh; Saied Ahmad A; Naderi Misagh; Rider Paul; Brylinski Michal; Chouljenko Vladimir N; Kousoulas Konstantin G^*

来源：Journal of Virology, 2016, 90(5): 2230-2239.

DOI：10.1128/JVI.02468-15

We have shown previously that herpes simplex virus 1 (HSV-1) lacking expression of the entire glycoprotein K (gK) or expressing gK with a 38-amino-acid deletion (gK Delta 31-68 mutation) failed to infect ganglionic neurons after ocular infection of mice. We constructed a new model for the predicted three-dimensional structure of gK, revealing that the gK Delta 31-68 mutation spans a well-defined beta-sheet structure within the amino terminus of gK, which is conserved among alphaherpesviruses. The HSV1(McKrae) gK Delta 31-68 virus was tested for the ability to enter into ganglionic neuronal axons in cell culture of explanted rat ganglia using a novel virus entry proximity ligation assay (VEPLA). In this assay, cell surface-bound virions were detected by the colocalization of gD and its cognate receptor nectin-1 on infected neuronal surfaces. Capsids that have entered into the cytoplasm were detected by the colocalization of the virion tegument protein UL37, with dynein required for loading of virion capsids onto microtubules for retrograde transport to the nucleus. HSV-1(McKrae) gK Delta 31-68 attached to cell surfaces of Vero cells and ganglionic axons in cell culture as efficiently as wild-type HSV-1(McKrae). However, unlike the wild-type virus, the mutant virus failed to enter into the axoplasm of ganglionic neurons. This work suggests that the amino terminus of gK is a critical determinant for entry into neuronal axons and may serve similar conserved functions for other alphaherpesviruses.
IMPORTANCE
Alphaherpesviruses, unlike beta-and gammaherpesviruses, have the unique ability to infect and establish latency in neurons. Glycoprotein K (gK) and the membrane protein UL20 are conserved among all alphaherpesviruses. We show here that a predicted beta-sheet domain, which is conserved among alphaherpesviruses, functions in HSV-1 entry into neuronal axons, suggesting that it may serve similar functions for other herpesviruses. These results are in agreement with our previous observations that deletion of this gK domain prevents the virus from successfully infecting ganglionic neurons after ocular infection of mice.

• 出版日期2016-3