Analysis of the T-Cell Receptor β-Chain Variable-Region (Vβ) Repertoire in Monozygotic Twins Discordant for Human Immunodeficiency Virus: Evidence for Perturbations of Specific VβSegments in CD4+T Cells of the Virus-Positive Twins

We analyzed the T-cell receptor (TCR) Vβrepertoire in human immunodeficiency virus type 1 (HIV-1)-infected individuals at different stages of disease. To circumvent the effect of HLA and other loci on the expressed TCR repertoire, we compared the TCR repertoire in nine pairs of monozygotic twins who were discordant for HIV infection. A semiquantitative polymerase chain reaction (PCR) assay and flow cytometry enabled us to show distinct differences in the Vβrepertoire in the HIV-positive twin compared with the HIV-negative twin. By combining PCR and cytofluorometry, these differences were restricted to a specific set of TCR Vβsegments, with members of the Vβ13 family perturbed in six out of seven cases and those of the Vβ21 family perturbed in four out of seven cases studied. Most of the other Vβfamilies remained unchanged. Our results provide direct evidence for a skewed TCR repertoire in HIV infection.