CD4+ AND CD8+ CIRCULATING ALPHA BETA T-CELL REPERTOIRES ARE EQUALLY COMPLEX AND ARE CHARACTERIZED BY DIFFERENT LEVELS OF STEADY-STATE TCR EXPRESSION/

The repertoire complexity of CD4+ and CD8+ T cells was measured in thr ee healthy blood donors for a number of TCR BV gene families by TCR sp ectratyping. This method subdivides V family-specific PCR products bas ed on CDR3 length. Genomic DNA was analyzed to determine the distribut ion of the cells bearing particular V-J rearrangements. cDNA was analy zed to measure the levels of transcripts arising from those same cells . The complexity and distribution of T cells in each lineage were equa l for most BV families. Certain families showed frequent skewing in CD 8 cells. Analysis of the intensity profiles of RNA versus DNA spectrat ypes indicated that in general, there is a constant ratio of transcrip t per cell for all rearranged sizes within a particular family. This r atio appeared higher in CD4 cells. Thus, steady-state levels of TCR mR NA were measured and found to be higher in CD4+ than in CD8+ cells.