Fig. 3. HSV Infection in epidermis of human skin-on-chip and native human skin.

a Schematic of epidermal HSV infection protocol by a biopsy punch. HSV-1 K26 virus (10⁶ PFU) was added on top of the epithelium after the stratified epidermis was disrupted by a 1.5 mm biopsy punch. b GFP expression of HSV-1 K26-infected 3-D skin-on-chip epidermis at 24 h post infection. Image shown as a maximum intensity projection of confocal z stacks. HSV-1 K26 (green). Scale bar: 500 µm. c HSV infection in the epidermis of skin-on-chip. Arrows indicate margination of chromatin, enlargement of the cell nucleus, and multi-nucleation. F-actin (red), HSV-1 K26 (red), DAPI (blue). Scale bar: 20 µm. d Human ulcerative HSV lesion in a representative genital skin biopsy. HSV (green), DAPI (blue). Scale bar: 200 µm (upper) and 20 µm (lower). e HSV infection of the basal layer (indicated by K14 staining) of the 3-D skin-on-chip epidermis. HSV-1 K26 (green), DAPI (blue), K14 or K10 (red). Scale bar: 20 µm.