CDR3β size distribution in PCC immunized mice. Tg-HLA-Cw3, Tg-KIR2DL3, and Tg-KIR2DL3 × HLA-Cw3 mice were immunized with PCC emulsified in CFA (PCC) as indicated. As a control, a group of Tg-KIR2DL3 × HLA-Cw3 mice were injected with CFA alone. The mRNA was extracted from the draining lymph node cells and reversely transcribed into cDNA. The cDNA from the indicated mice was subjected to PCR using Vβ3.1- and Cβ-specific primers followed by a run-off with fluorescent Jβ1.2- and Jβ2.3-specific oligonucleotides. The size distribution was analyzed with the Immuoscope software. Data shown are representative from 3 mice per group. Analysis of Vβ3-Jβ2.3 was performed as a negative control. The arrows indicate the Vβ3-Jβ1.2 rearrangement with a 9 amino acid long CDR3β that is dominant upon PCC immunization.