These results also establish that the naïve D b NPN3A + CD8 + TCR repertoire (Fig. 4C) is predictive of the immune D b NPN3A + CD8 + TCRb response ( Table 2 ). The relative lack of a ''public'' response translated to a profile of reduced ''sharing'' between individual mice, and a total increase in the number of D b NPN3A + CD8 + clonotypes due to the 'private' nature of TCRb repertoire for each mouse (Table 2 ). Even so, the clonotypic diversity within individual NPN3A virus-infected mice was reduced compared to the spectrum found following wt virus-infection. This was true whether the cells were sorted using the wt D b NP 366 or the mutant D b NPN3A tetramer, reflecting the significant cross-reactivity between the D b NP 366 and D b NPN3A-specific populations recovered from mice infected with the NPN3A viruses. By the measure of tetramer binding, it thus seems that the NPN3A virus is selecting a less diverse repertoire than the wt virus, with the repertoire being almost completely cross-reactive with that elicited by the wt D b NP 366 epitope.