Establishment of Psoriasis in BALB/c Murine Model using Imiquimod: A Pilot Study

Abstract

Psoriasis is an immune-mediated inflammatory disease exploiting the skin which is triggered by many possible factors concerning the epidermal keratinocytes and autoimmune cells. To study psoriasis in vivo, imiquimod (IMQ) topical application is used as it is a ligand of TLR7 in mouse to induce an acute psoriatic murine model. In obtaining the expected outcomes, one must understand the fundamental procedures to successfully initiate psoriasis in mouse. As IMQ is an acute psoriasis model inducer, it has been proposed that the condition can be progressed up to seven days after application. Aldara cream containing 5% imiquimod and Vaseline as its control was topically applied for seven days consecutively on the shaved back of the BALB/c mice. Modified Psoriasis Area and Severity Index (PASI) score was used to score the inflammation severity of the induced area. The exacerbation of the diseased skin in the mouse was seen to be more severe as it developed. The increasing PASI score of the psoriatic mouse from 2 to 7 by days suggested that psoriasis establishment had made evidence which consists of progressed erythema, skin thickening and scaling. The spleen in the psoriatic mouse portrayed splenomegaly in a gross observation compared to the control spleen. Hence, using this method with such dosage further agrees that it is the most suitable dosage and can provide a good immunological framework for establishing psoriasis in vivo.