Heounjeong Go

Pellino‐1 plays a crucial role in cellular proliferation and regulates inflammatory processes. This study investigated Pellino‐1 expression patterns and their relationship with CD4 + T‐cell subsets in psoriasis patients. Group 1 comprised primarily biopsied psoriasis lesions from 378 patients, multiplex‐immunostained for Pellino‐1, CD4 and representative T helper (Th) cells (T‐bet [Th1], GATA3 [Th2], and RORγt [Th17] and regulatory T cell [FoxP3] markers). Ki‐67 labeling was evaluated in the epidermis. Group 2 comprised 43 Pellino‐1‐positive cases immunostained for Pellino‐1 in both lesion and non‐lesion skin biopsy samples. Five normal skin biopsies served as controls. Among 378 psoriasis cases, 293 (77.5%) were positive for Pellino‐1 in the epidermis. Pellino‐1‐positivity was higher in psoriasis lesions than in non‐lesions and normal skin (52.55% vs. 40.43% vs. 3.48%, p < 0.001; H‐score, 72.08 vs. 47.55 vs. 4.40, p < 0.001, respectively). Pellino‐1‐positive cases also had a significantly higher Ki‐67 labeling index ( p < 0.001). Epidermal Pellino1‐positivity was significantly associated with higher RORγt + ( p = 0.001) and FoxP3 + ( p < 0.001) CD4 + T cell ratios but not T‐bet + and GATA3 + CD4 + T cell ratios. Among the CD4 + Pellino‐1 + T‐cell subsets, the CD4 + Pellino‐1 + RORγt + ratio was significantly associated with epidermal Pellinio‐1 expression ( p < 0.001). Pellino‐1 expression is thus increased in psoriasis lesions and associated with increased epidermal proliferation and CD4 + T‐cell subset infiltration, especially Th17 cells. This suggests that Pellino‐1 could be a therapeutic target that simultaneously regulates psoriasis epidermal proliferation and immune interactions.