Nonprofessional Phagocytosis Can Facilitate Herpesvirus Entry into Ocular Cells

Figure 1

Herpesvirus infection leads to increase in the number of F-actin-rich projections. (a)–(c) Counting of the projections on per cell basis was done 15–30 min before and after the addition of the virus indicated (Herpes simplex virus type-1; (HSV-1), Cytomegalovirus; (CMV) and Human herpesvirus-8; (HHV-8)). In this and all other subsequent experiments cells used included corneal fibroblasts (CFs) (a) for HSV-1, human retinal pigment epithelial (RPE) cells for CMV (b), and primary cultures of human conjunctival epithelial (HCjE) for HHV-8 (c) infection. Four independent experiments were conducted to record the data. Numbers of actin-rich protrusions are presented as means with error bars showing standard deviation. (d)–(f) Confocal images of cells challenged with indicated viruses are shown. Virally infected cells were fixed, permeabilized, and stained for F-actin with 10 nM rhodamine-conjugated phalloidin before mounting (Vectashield mounting medium). All confocal (Leica SP2) images were captured at 63x objective. Magnified views of the images in the boxes are shown next to them and labeled identically. CMV and HHV-8 viruses were identified by monoclonal antibodies against CMV envelope glycoprotein gB and HHV-8 K8.1A (1 : 50) followed by secondary antibody treatment conjugated to FITC.