PERIPHERAL CD25 POSITIVE T-LYMPHOCYTES WITH BIASED T-CELL RECEPTOR V-BETA GENE USAGE IN AUTOIMMUNE ENDOGENOUS POSTERIOR UVEITIS

Aims-To determine T cell receptor (TCR) V beta gene usage in peripheral blood T lymphocytes of patients with endogenous posterior uveitis (EPU). If biased TCR variable (V) gene usage occurs in this autoimmune disease, it should be detectable in immune activated peripheral blood T cells in vivo. Methods-Relative proportions of each V beta gene family expressed in total peripheral blood lymphocytes (PBL) and in vivo activated (CD25 +) T cells from patients with EPU and controls were determined using the anchored polymerase chain reaction (anchored PCR) in conjunction with a novel hybridisation assay. The TCR V beta repertoires seen in these cell populations were then compared. Results-V beta 1 usage within the CD25 + lymphocytes of patients with EPU was substantially elevated (mean +/- SD 15 +/- 9%) compared with control CD25 + cells (3.3 +/- 2.4%). Conclusions-By contrasting the repertoires of these cell populations, biased TCR V beta gene usage was detected in patients with EPU, namely increased usage of V beta 1 in CD25 + T cells from peripheral blood of these patients. This approach of directly analysing the activated T cells in blood, using bulk PBL as an internal control, has wide applicability where specific T cell subpopulations are thought to play an important aetiopathological role.