Abstract
Purpose :
To investigate the cellular receptors and molecular mechanisms of herpes simplex virus type 1 (HSV-1) entry into corneal nerves.
Methods :
Immunofluorescence was performed to determine the distribution and expression of HSV-1 entry receptors in corneal nerves of healthy mice, including nectin-1, herpes virus entry medium (HVEM), non-muscle myosin heavy chain IIA (NMHC-IIA), NMHC-IIB, and myelin-associated glycoprotein (MAG). Quantitative real-time Polymerase Chain Reaction (qPCR) were used to further analyze the expression of HSV-1 receptors in trigeminal ganglion (TG) from healthy and Herpes Simplex Keratitis (HSK) mice. Enzymatic digestion and density gradient centrifugation was used to isolate TG to single TG neurons. Antibody antagonism and siRNA techniques were employed to investigate the functional receptors mediating HSV-1 entry into cultured TG neurons from mice in vitro. Subconjunctival injection of specific antibodies was then performed to further explore the roles of functional receptors in vivo.
Results :
We observed that Nectin-1, HVEM, NMHC-IIA and NMHC-IIB were expressed in healthy corneal nerves, but MAG not. MAG was only expressed on the myelin sheaths in TG, and was nearly unexpressed in cultured TG neurons. On day 3 post-infection, the expression of nectin-1, HVEM and NMHC-IIB in TG was significantly increased, while NMHC-IIA was decreased. HSV-1 entry was significantly inhibited in Nectin-1 or NMHC-IIB knockdown TG neurons in vitro, but had little inhibitory effect in HVEM or NMHC-IIA knockdown TG neurons. Also, in vivo antibody antagonism of nectin-1 or NMHC-IIB inhibited HSV-1 entry into corneal nerves and reduced virus replication in TG.
Conclusions :
Nectin-1, HVEM, NMHC-IIA, and NMHC-IIB were expressed in corneal nerves of healthy mice. However, nectin-1 and NMHC-IIB may play the predominant role in mediating HSV-1 entry.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.