CELL-RECEPTOR V-BETA USAGE BY LESIONAL LYMPHOCYTES IN ORAL LICHEN-PLANUS

To determine whether the T-cell inflammatory infiltrate in oral lichen planus (OLP) represents a selective activation and expansion of a lim ited repertoire of T-cell receptor (TCR) specific T-cells, V beta gene expression was investigated in lesional T-lymphocytes in OLP. A rever se transcriptase-polymerase chain reaction (RT-PCR) technique was used to amplify the 24 major V beta gene sub-families of infiltrating muco sal lymphocytes and peripheral blood mononuclear cells (PMNC) in seven patients with reticular OLP and four healthy control patients. Specif icity of amplified products was confirmed by Southern blotting with a C beta internal probe. TCR V beta usage by lesional T-cells in OLP was markedly heterogeneous 5-23 V beta sub-families). In 6/8 patients wit h OLP, V beta usage was restricted with less than or equal to 20/25 su b-families detected; only one of the V beta sub-families (V beta 8) wa s present in all of the OLP patients demonstrating TCR V beta restrict ion. In contrast, TCR V beta usage was unrestricted in PMNC from OLP p atients and controls (greater than or equal to 23/25 sub-families dete cted). In three patients, certain V beta sub-families (V beta 13, V be ta 14 & V beta 15) were present in the lesional T-cell population bur were underrepresented in PMNC. These results suggest a selective V bet a gene usage by lesional infiltrating T-cells in oral lichen planus. T he non-uniformity of V beta restriction in lesional T-cells does not s upport the concept of a common superantigen in OLP and reflects the he terogeneity of the disease.