T-cell repertoire analysis. (A) Percentage of CD4⁺ and CD8⁺ T cells expressing the indicated TCR Vβ chains from the patient (▩) and median and range from healthy controls as determined by flow cytometry.²⁵  (B) CDR3 length profile of the indicated Vβ populations from the patient (P2) and a 6-month-old healthy donor (HD). cDNA was prepared from PBMC RNA and amplified using Vβ–specific primers, and the size distribution of PCR products was determined by an automated sequencer and GeneMapper software version 4.0. The relative fluorescence intensity of the bands is shown as a function of the PCR fragment size. (C) CDR3 length profile of γδ T cells using Vδ2- and Vγ9-specific primers.