Efficient immune responses in mice lacking N-region diversity.
Gilfillan S., Bachmann M., Trembleau S., Adorini L., Kalinke U., Zinkernagel R., Benoist C., Mathis D.
Mice with a null mutation in the terminal deoxynucleotidyl transferase (TdT) gene harbor immunoglobulin and T cell receptor repertoires essentially devoid of N-region diversity. Consequently, the CDR3 loops important for antigen recognition are shorter and considerably less diverse than those of wild-type controls. We find surprisingly normal immune responses in TdT0 mice, as regards both efficiency and specificity. This provokes a reconsideration of the assumption that N-region diversity is required for an effective T and B cell repertoire.