Expression of T-cell receptor V beta regions in granular lymphocyte-proliferative disorders.

In a recent issue of Blood, de Totero et all reported the preferential T-cell receptor (TCR) V region usage in the expansion of CD8' granular lymphocytes (GL). They found that both monoclonal and polyclonal CD8+TCRa@+ GL shared the Vp5.3 region, as shown by their positivity for LC4 monoclonal antibody (MoAb), and suggested a preferential Vp gene segment usage in the rearrangement process of CD8+ GL. We also studied the usage of TCR Vp regions of peripheral blood lymphocytes (PBL) in patients with GL-proliferative disorders (GLPD). GLPD are characterized by the proliferation of GL in the peripheral blood.233 Based on the surface phenotypes of the proliferating GL, GLPD are divided into CD3+ T-cell-lineage GLPD (TGLPD) and CD3natural killer cell-lineage GLPD. The GL of most T-GLPD patients are monoclonally rearranged, and these GL are thought to be a proliferation of cytotoxic T lymphocytes of unknown antigen specifi~ity.~.~ Investigation of the usage of TCR variable regions in T-GLPD is thought to be important in the study of the pathogenesis of the disorders. Murine MoAbs reactive with human TCR variable regions are now commercially available to study the repertoire of TCR expressed under many conditions. In this study, we used MoAb Diversi-T a@ TCR Screening Panels 1 F (lot 2800; T Cell Diagnostics, Cambridge, MA) and those from Immunotech S.A. (Marseille, France). Data analysis was performed with EPICS Profile I1 (Coulter Co, Hialeah, FL) by appropriately gating lymphoid populations.