Background: The infiltrating cells in psoriasis include a subpopulation of autoreactive T cells.
Objective: The aim of this study was to further characterize skin-infiltrating T lymphocytes in patients with psoriasis.
Methods: Forty-five T-cell clones were generated from skin biopsy specimens from two patients.
Results: Phenotypic studies on 25 of 45 clones revealed that 19 (76%) of the clones were CD4+, 5 (20%) were CD8+, and 1 (4%) clone was CD4- and CD8-. Twenty-three clones were stained for identification of T-cell receptors. Twenty-two clones expressed alpha/beta T-cell receptors and one clone (CD4-/CD8-) expressed no T-cell receptor. Nineteen clones (42%) were autoreactive with no restriction to class I or class II HLA antigens. By contrast, proliferation of two of the seven clones was inhibited by class I monoclonal antibody, whereas proliferation of four of seven clones was inhibited by class II monoclonal antibody.
Conclusion: These data suggest that skin-infiltrating lymphocytes in patients with psoriasis may recognize HLA-associated molecules, perhaps the peptide of the HLA groove. The recognition of the peptide is presumably inhibited when monoclonal antibody is bound to the HLA molecule.