Figure 6. Clonal composition and expression of IL7Rα and IL15Rβ by expanded gB-8p-specific memory CD8⁺ T-cells in old mice.

A. CDR3 length analysis of the BV segments involved in gB-8p-specific CD8⁺ T cell response in mice undergoing late-age memory inflation. CD8⁺ T-cells from mice exhibiting old-age memory inflation were purified using magnetic bead separation, the RNA was extracted and the diversity of CDR3 lengths of BV8 (8.1, 8.2 and 8.3) and BV10 segments was determined as described in Materials and Methods. CDR3 profiles from three representative mice are shown. B. Elevated expression of IL7Rα (CD127) and IL15Rβ (CD122) on expanded gB-8p-specific memory cells in old mice. Splenocytes from old latently infected mice (n=6) undergoing old-age memory inflation were stained with CD8, CD44, CD62L, tetramer, CD127 and CD122. The percentage of CD122⁺ and CD127⁺ cells as well as the mean fluorescent intensity (MFI) of CD127 was compared between central memory phenotype (CD44⁺ CD62L⁺) tetramer⁺ (top panels) or tetramer^- (bottom panel) CD8⁺ T-cells. The values represent the average ± SD (first two rows) or the p-value (obtained from paired Student’s t-test comparing the values from the tetramer⁺ and tetramer^- fraction of cells of individual mice), and the data is representative of two independent experiments.