T-cell receptor V beta repertoire CDR3 length diversity differs within CD 1 SRA and CD45RO T-cell subsets in healthy and human immunodeficiency virus-infected children

The T-cell receptor (TCR) CDR3 length heterogeneity is formed during recomb ination of individual V beta gene families. We hypothesized that CDR3 lengt h diversity could be used to assess the fundamental differences within the TCR repertoire of CD45RA and CD45RO T-cell subpopulations. By using PCR-bas ed spectratyping, nested primers fur all 2-1 human V beta families were dev eloped to amplify CDR3 lengths in immunomagnetically selected CD45RA and CD 45SRO subsets within both CD4(+) and CD8(+) T-cell populations. Umbilical c ord blood mononuclear cells or peripheral blood mononuclear cells obtained from healthy newborns, infants, and children, as well as human immunodefici ency virus (HIV)-infected children, were analyzed. All T-cell subsets from newborn and healthy children demonstrated a Gaussian distribution of CDR3 l engths in separated T-cell subsets. In contrast, HIV-infected children had a high proportion of predominant CDR3 lengths within both CD45RA and CD45RO T-cell subpopulations, most commonly in CD8(+) CD45RO T cells, Sharp diffe rences in clonal dominance and size distributions were observed when cells were separated into CD45RA or CD45RO subpopulations. These differences were not apparent in unfractionated CD4(+) or CD8(+) T cells from HIV-infected subjects, Sequence analysis of predominant CDR3 lengths revealed oligoclona l expansion within individual VP families, Analysis of the CDR3 length dive rsity within CD45RA and CD45RO T cells provides a more accurate measure of disturbances in the TCR repertoire than analysis of unfractionated CD4 and CD8 T cells.