Humanized mouse model of Psoriasis

The humanized psoriatic SCID/Beige mouse model uses healthy human skin grafts, and PBMCs from patients with Psoriasis that were cultured in the presence of high‐dose IL‐2 (IL‐2‐activated PBMCs). This promotes the growth of different PBMCs that are enriched for activated T cells bearing Natural Killer (NK) receptors.²⁷, ²⁸

Ten C.B‐17/IcrHsd‐scid‐bg mice were used (Harlan, Jerusalem, Israel). Animal handling was in accordance with the national guidelines, and approved by the Technion Animal Care and Use Committee. Mice were housed with an artificial 12‐hr/12‐hr light/dark cycle at constant temperature, and were fed with standard chow and water ad libitum. The mice were acclimatized for 1 week before experimentation.

Following skin transplantation, PBMCs were isolated from donors with Psoriasis by centrifugation of Ficoll/Hypaque (Pharmacia; Amershem Pharmacia Biotech, Uppsala, Sweden). The PBMCs were cultured for 14 days with 100 U/ml human IL‐2 (PROSPEC, Protein Specialists, https://www.prospecbio.com), in filtered medium composed of RPMI‐1640, 10% human AB serum (Sigma‐Aldrich), 1% l‐glutamine and 1% penicillin‐streptomycin (media components; Biological Industries, Kibbutz Beit Haemeck, Israel). The medium was changed as needed. The cells were then injected intradermally (7 × 10⁶) into the grafts.