Clonal breadth of the HIV-1-specific T-cell receptor repertoire in vivo as determined by subtractive analysis.

Objective: Although the epitopic breadth of HIV-1-specific CD8 T lymphocyte (CTL) responses has been described, the T cell receptor (TCR) diversity of virus-specific cells remains poorly defined.

Methods: To address this issue, we applied a novel technique for subtractive analysis of the HIV-1-specific CTL repertoire, combining specific deletion of peptide-specific cells by 5-fluorouracil with TCR spectratyping to identify clonal breadth of CTL recognizing individual peptides.

Results: Comprehensive analysis of an infected individual reveals that nine identified HIV-1-specific responses are comprised of at least 38 distinct T-cell clones (ranging from two to 10 distinct clones per epitope).

Conclusions: Given the potentially crucial role of T-cell receptor breadth for viral recognition and avoidance of escape, this subepitopic analysis of CTL may offer an important measure of cellular immunity for pathogenesis and vaccine studies.