Lymphocytes were firstly gated for CD4⁺CD25⁺ T cells derived from spleens of either Cd18^wt or Cd18^hypo affected mice (A) and thereafter analyzed for CD127 expression (B). The percentage of CD127⁺ (top corner) and CD127^– (bottom corner) T cells within CD4⁺CD25⁺ T cell gate is shown. The panel on the right shows isotype matched IgG control staining. (C) Percentage of CD4⁺CD25⁺CD127^– T cells in thymus, blood, spleen, and DLNs of Cd18^wt and affected Cd18^hypo mice with psoriasiform skin disease (n = 6 for each genotype and organ). The experiment was done twice, the median is shown. (D) To investigate CD127 expression by CD25⁺ T cells in the skin of affected Cd18^hypo mice, skin cryosections from Cd18^wt and affected Cd18^hypo mice were double stained with CD25–Alexa Fluor 488 (green) and CD127-PE (red). Cell nuclei (blue) were counterstained with DAPI (original magnification, ×20). Red cells indicate CD25^–CD127⁺ T cells and green cells represent CD25⁺CD127^– Tregs, while overlay (yellow) represents double-positive T cells. e, epidermis; d, dermis; h, hair follicle. The dotted line indicates the border between epidermis and dermis. (E) To quantify CD25⁺CD127⁺ or CD25⁺CD127^– T cells in the skin of affected Cd18^hypo and Cd18^wt mice, the positively stained cells were counted. For all measurements, the median of specifically stained T cells counted in 15 high-power fields (HPFs) is presented (n = 5). *P < 0.05, **P < 0.01, using Student’s t test.