T-CELL LINES DERIVED FROM LESIONAL SKIN OF LICHEN-PLANUS PATIENTS CONTAIN A DISTINCTIVE POPULATION OF T-CELL RECEPTOR GAMMA-DELTA-BEARING CELLS

Lichen planus is characterized by a dense infiltrate of T lymphocytes at the dermoepidermal junction. To determine the phenotypic and functional characteristics of the infiltrating lymphocytes, T-cell lines from normal and lesional skin from the same patients with lichen planus were established by culture with interleukin 2 followed by stimulation every 14 d with phytohemagglutinin and irradiated allogeneic feeder cells. Resultant T-cell lines were immunophenotyped by staining with monoclonal antibodies and their reactivity tested by determining their cytolytic activity to selected targets. T-cell lines from 13 lesional and nine normal biopsy specimens were studied. T-cell lines from normal skin were 61% CD4(+) and 32% CD8(+), whereas lines from lesional skin had significantly fewer CD4(+) cells (13%) and more CD8(+) cells (62%). T-cell lines from lesional skin contained a distinctive population of gamma delta T cells that was rarely present in lines derived from normal skin. We were able to culture gamma delta T cells out of the lesional skin of 12 of 13 patients. In these 12 patients, lesional T-cell lines were 17% gamma delta(+) (range 2% to 47%). Only one T-cell line from normal skin contained significant numbers of gamma delta T cells. The gamma delta population from lesional skin was commonly V(delta)1J(delta)1(+). These results suggest that CD8(+) and TCR gamma delta(+) T lymphocytes may be involved in the development or the maintenance of lichen planus.