Figure 5

In vivo knockdown of IL-12B in xenografted psoriatic skin by lentiviral delivery of anti-IL12B shRNAs. (a) Schematic schedule of treatment with shRNA-encoding lentiviral vectors (upper panel) and topically applied steroid (lower panel). Psoriatic skin grafts were xenografted onto the back of SCID mice and allowed to heal for ten days. The skin grafts were then either left untreated or treated by a single intradermal injection of lentiviral vectors encoding either shIL12B #6 or an irrelevant shRNA, or treated daily with the topically applied class three steroid, Betnovat (positive control). The mice were sacrificed three weeks after treatment. The two groups consisting of untreated mice and mice treated with lentiviral vectors encoding an irrelevant shRNA were pooled to a single group (negative control) due to high similarities in the semiquantitative clinical psoriasis scores and epidermal thicknesses. (b) Semiquantitative clinical psoriasis scores were given twice weekly for the three-week treatment duration to mice treated with negative control (open circles, n = 16), LV-shIL12B #6 (open squares, n = 11), or Betnovat (crosses, n = 6). Intradermal injections were performed at day 0. All data points are presented as mean ± SEM. *p = 0.86, **p = 0.12. (c) At treatment endpoint three weeks post-transduction of the skin grafts, mice were sacrificed and biopsies from the skin grafts were fixed, paraffin-embedded, H&E-stained, and epidermal thickness was measured in each graft. (d) Biopsies from the xenografted psoriatic skin injected with shRNA-encoding lentiviral vectors were acquired at treatment endpoint three weeks post-transduction and evaluated for IL-12B gene expression by qRT-PCR. Data are presented as mean + SEM. (e) Immunohistochemical stainings were performed for Ki-67, CD4, CD8, SKALP/Elafin, and hBD2 on skin sections treated with LV-shIrrelevant or LV-shIL12B #6.