FIG. 2.

HSV infection of human T cells occurs preferentially via cell-cell spread. The Jurkat T cell line (A and D), a CD8⁺ T-cell clone (B and E), or PBMC (C and F) were either infected with cell-free HSV-1(F) at an MOI of 10 at 37°C (A to C) or coincubated at 37°C with human fibroblasts infected with HSV-1(F) or HSV-2(HG52) at an MOI of 10 for 5 h at 37°C (D to F). At 16 to 18 h postinfection or exposure, cells were collected, stained for T-cell markers and HSV antigens, and analyzed by flow cytometry. The percentage of HSV-positive T cells (CD3⁺ HSV positive) is indicated below each window. For PBMC infected by coincubation with HSV-infected fibroblasts, the inset shows the percentage of CD4⁺ (upper left quadrant) and CD8⁺ (lower right quadrant) cells among infected CD3⁺ T cells.