FIG. 1.

Spontaneous (A) and antibody-dependent (B) internalization of PRV gB are both dependent on an intact YQRL motif. Confluent monolayers of PK15 cells were infected at an MOI of 10 with either PRV Be or PRV Y902A. At 6 (left column) and 10 (right column) h p.i., the efficiency of spontaneous internalization was studied by determining the levels of gB remaining at the cell surface (A), whereas antibody-dependent internalization was studied using an internalization assay based on FITC-labeled anti-gB antibodies, as described in Materials and Methods (B). The cells were analyzed by confocal microscopy. Bar, 10 μm.