The distinct role and regulatory mechanism of IL-17 and IFN-γ in the initiation and development of plaque vs guttate psoriasis

•Th-1 predominant activation represents stable plaque morphology, and Th-17 activation indicates the progressive stage of psoriasis such as guttate psoriasis.•CD4+CD25highTregs in guttate vs plaque psoriasis can inhibit the production of IFN-γ rather than IL-17 from CD4+CD25- T cells.•Crucial effector cytokines IL-17 and IFN-γ predominantly come from activated CD4+T cells in guttate psoriasis while they come from activated CD8+T cells in plaque psoriasis.