PREFERENTIAL EXPRESSION OF TCR V-ALPHA REGIONS IN CD4 CD8 SUBSETS - CLASS DISCRIMINATION OR CORECEPTOR RECOGNITION/

The preferential expression of T-cell receptor (TCR) V alpha regions i n the CD4(+) and CD8(+) T-cell subsets suggests that they have a speci al role in distinguishing recognition of major histocompatibility comp lex (MHC) class I from class II, or CD4 from CD8. Here, Bee-Cheng Sim, David Lo and Nicholas Gascoigne review recent data indicating the mol ecular basis for this discrimination, and how polymorphism within V al pha subfamilies and between TCR alpha-chain haplotypes contributes to the T-cell repertoire.