Immortalized Vaginal Epithelial Cell Line

The WT VK2/E6E7 vaginal epithelial cell line was obtained from the ATCC (Manassas, VA, USA). This cell line (ATCC CRL-2616) was derived from normal human vaginal mucosal tissue and immortalized at passage 3 by transduction with the retroviral vector LXSN-16E6E7 in the presence of polybrene. The VK2 cells and the two TRIM26-modified VK2 variants (see below) were grown and maintained in keratinocyte serum-free medium (KSFM). KSFM was supplemented with an additional 0.1 ng/mL of human recombinant epidermal growth factor, 0.05 mg/mL of bovine pituitary extract, 0.4 mM CaCl₂, and 100 units/mL penicillin-streptomycin (Life Technologies, Carlsbad, CA, US), as described before [21 (link)]. KSFM, human recombinant epidermal growth factor, and bovine pituitary extract were obtained from Life Technologies. Human embryonic kidney (HEK) 293T cells containing the SV40 T-antigen (ATCC Manassas) were cultured in high glucose formulation of Dulbecco’s modified eagle’s medium (DMEM) with 4.5 g/L of glucose and supplemented with 10% fetal bovine serum (FBS). African green monkey kidney or Vero cells (ATCC) were cultured in minimum essential medium eagle-alpha modification (α-MEM) supplemented with 5% of FBS and 1% of l-glutamine, penicillin-streptomycin, and HEPES.