Comparison of the phenotypes of infiltrating T cells in the dermis and epidermis of psoriatic skin
Objective To investigate the immunological pathogenesis in the development of psoriasis vulgaris(PV). Methods With immunoenzymatic staining (streptavidin/peroxidase, SP) technique, we compared the expression and phenotypic profile of infiltrating T cells and the expression of E selectin in normal ( n =10), uninvolved perilesional ( n =26) and lesional psoriatic ( n =35) skin of different stages (progressing, stable or regressing) and normal human skin. Results ① In the lesions of PV at progressive stage, the number of CD4 + cells, CD8 + cells and CD45RO + cells in epidermis, CD3 + cells, CD4 + cells, CD8 + cells, CD45RO + cells and CLA + cells in dermis were much more than that in the lesions of PV at stable stage. ② In the psoriatic lesions at stable stage, the number of CD3 + cells in epidermis, CD3 + cells, CD4 + cells, CD8 + cells, CD45RO + cells and CLA + cells in dermis were much more than those at regressive stage, but CD8 + cells in epidermis was less than that at regressive stage. ③ The number of CD4 + cells in the epidermis of uninvolved perilesional PV skin at progressive stage was much more than that of uninvolved perilesional PV skin at stationary stage. ④ There was no significant difference at phenotypic profile of T cells between normal skin of PV and normal human skin. ⑤ The number of infiltrating CLA T cells was significantly correlated with the degree of expression of E selectin on dermal microvessel in uninvolved perilesional and lesional psoriatic skin at each stage. Conclusion The infiltrating T cells in the psoriatic lesions mainly expressed CLA and CD45RO phenotype and CD4 + cells might play an important role in the initiation and maintenance of PV, but the role of CD8 + cells can not be exacluded. The interaction of E selectin and CLA plays an important role in the mediation T cells recruitment to the skin.