Background: Activated T cells present in psoriatic plaques play a key role in the pathogenesis of psoriasis. CCR7 on T cells plays a crucial role in native immune response and formation of secondary lymphoid organ.
Aims: To determine whether differential expression and functions of the CCR7 occur in psoriasis patients in China, we examined CCR7 on T cells from normal and psoriasis subjects.
Methods: Skin specimens and T cells from 33 patients and 22 healthy controls were analyzed by immunohistology, flow cytometry, and RT-PCR.
Results: Patients with psoriasis had a skewed distribution of T lymphocytes, with an increased level of CCR7+ T lymphocytes compared to healthy controls (P<0.01) By flow cytometry, it was found that CCR7 was selectively, frequently, and functionally expressed on CD4+ (20.5+/-6.8%)but not on CD8+ (9.5+/-3.4%) T cells from patients with psoriasis, whereas this phenomenon was not seen in normal subjects. Through RT-PCR it was also found that CCR7 was highly expressed on T cells in patients with psoriasis than in healthy controls in the level of gene.
Conclusions: Patients with psoriasis had a skewed distribution of T lymphocytes, with an increased level of CCR7+ T lymphocytes compared to healthy controls. CD4+ CCR7+ T cells had abnormal expression, which might induce protraction and persistence of psoriasis.