T-cell lines derived from lesional skin of lichen planus patients contain a distinctive population of T-cell receptor γδ-bearing cells

Abstract 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 γδ T cells that was rarely present in lines derived from normal skin. We were able to culture γδ T cells out of the lesional skin of 12 of 13 patients. In these 12 patients, lesional T-celt lines were 17% γδ + (range 2% to 47%). Only one T-cell line from normal skin contained significant numbers of γδ T cells. The γδ population from lesional skin was commonly V δ 1J δ 1 + . These results suggest that CD8 + and TCR γδ + T lymphocytes may be involved in the development or the maintenance of lichen planus.