Expression pattern of cytokeratin 10 in untreated and lopinavir/ritonavir treated gingival raft cultures. Primary gingival keratinocytes were grown in organotypic (raft) cultures and treated with different concentrations of lopinavir/ritonavir at day 8. (Panels a, g and m) untreated rafts; (Panels b, h and n) rafts treated with 3 µg/ml lopinavir/ritonavir; (Panels c, i and o) rafts treated with 6 µg/ml lopinavir/ritonavir; (Panels d, j and p) rafts treated with 9.8 µg/ml lopinavir/ritonavir; (Panels e, k and q) rafts treated with 13.5 µg/ml lopinavir/ritonavir; (Panels f, l and r) rafts treated with 16 µg/ml lopinavir/ritonavir. Rafts were harvested at different points and stained with anti-cytokeratin 10 antibody. (Panels a to f) rafts were harvested at 2 days post treatment; (Panels g to l) rafts were harvested at 4 days post treatment; (Panels m to r) rafts were harvested at 6 days post treatment. Arrows indicate the expression of cytokeratin 10. Images are at 20 × original magnification.