FIG. 9.

Premature termination of transgene expression yields memory cells with a greater capacity for TNF-α production. Spleens and peripheral blood were harvested from mice 90 days postimmunization, and SIINFEKL-specific CD8⁺ T cells were identified by intracellular cytokine staining. (A) Representative flow cytometry data. Left-hand dot plots reflect total lymphocytes following stimulation with SIINFEKL. The percentages of cells in the entire lymphocyte populations that are positive for IFN-γ are given next to the ellipses. The right-hand plots were gated on IFN-γ⁺ cells. These plots are representative of mice that were treated with DOX 30 days after immunization (DOX d+30) and mice that did not receive DOX (No DOX). (B) Percentages of IFN-γ⁺ cells that coproduce TNF-α in the spleen (left) and blood (right). Each histogram represents the mean ± standard error of the mean for five mice. *, significantly different from the No DOX group (P < 0.05).