FIG. 3.

Induction and maintenance of Tag-specific CD8⁺ lymphocytes following immunization with Tag-transformed cells. Groups of three C57BL/6 mice were immunized with transformed cells which expressed either the wild-type Tag (B6/WT-19) or an epitope-negative substituted derivative (B6/T122B1). Spleens were harvested at 9, 17, or 90 days postimmunization, and lymphocytes were pooled and analyzed by FACS analysis following staining with anti-CD8 and Tag-specific tetramers (Db/I Tet, Db/II/III Tet, Kb/IV Tet, and Db/V Tet) or a control tetramer (Kb/gB Tet). Results are presented as the number of CD8⁺ Tet⁺ cells per spleen. Epitope II/III-specific T-cell responses were not determined at 17 days. Staining with control tetramers routinely ranged between 0.8 × 10⁴ and 1.8 × 10⁴ CD8⁺ T cells per spleen in these experiments (D).