The MHC class I-restricted T cell response to Sendai virus infection in C57BL/6 mice: a single immunodominant epitope elicits an extremely diverse repertoire of T cells.

We have used Sendai virus infection of C57BL/6 mice as a model with which to study the T cell response to a single MHC class I epitope. Cells taken from the bronchoalveolar lavage or restimulated in vitro from the mediastinal lymph nodes of virus-infected mice were strongly cytotoxic for a single nucleoprotein epitope, NP324-332/Kb. To correlate TCR usage with specificity for the immunodominant epitope, we generated T cell hybridomas from the bronchoalveolar lavage and mediastinal lymph node cells of C57BL/6 mice at the peak of infection. Altogether, 20 hybridomas were identified that specifically secreted IL-2 in response to NP324-332-pulsed L929-Kb cells. TCR usage in this panel of hybridomas was extremely diverse. Over half of the available J beta and V beta elements present in the C57BL/6 strain of mouse were represented in the hybridomas. Similarly, V alpha usage was also diverse and all 12 of the alpha chains sequenced used distinct J alpha elements. The only relatively conserved feature of the TCR in these hybridomas was the presence of an arginine residue in the junctions of 70% of the beta chains. These data demonstrate that a diverse repertoire of TCR is able to recognize a single MHC class I epitope. Moreover, the data demonstrate that mice make use of this potential diversity in the primary response to a natural viral infection.