For surface marker staining, cells were washed twice in buffer A (five minutes, 10006g) and resuspended in primary antibody (1:200 in buffer A, 25% 24G2 [74] ). The following primary antibodies were used: CD106-biotin (Rat, IgG2a k, clone 429 (MVCAM.A)), CD54-FITC (Armenian hamster, IgG1 k, clone 3E2), Thy1.2-APC (Rat, IgG2a k, clone 53-2.1) (BD Bioscience), monoclonal mouse anti-cHV68 gp150 (mouse IgG2a, a kind gift from Dr. Phillip Stevenson) [75] . Cells were then incubated for 45 minutes at room temperature. Following incubation, cells were centrifuged twice in buffer A (five minutes, 10006g), resuspended in either buffer A or secondary staining reagent in buffer A (1:500), and incubated for 20-30 minutes at room temperature. Secondary staining reagents were either streptavidin-APC (BD Bioscience) or anti-mouse IgG2a-FITC (Rat IgG1 k, clone R19-15) (BD Bioscience). Cells were centrifuged twice in buffer A (five minutes, 10006g) and analyzed by flow cytometry.