Figure 3. Robust T cell and plasma cytokine responses were observed.

(A) FACS plots of singlet, live, CD3⁺, CD4⁺, and CD8⁺ lymphocytes at baseline and on day +5, identifying activated HLA-DR⁺CD38⁺ T cells. (B) Percentage of activated CD4⁺ (purple) and CD8⁺ (orange) T cells over time as analyzed in A. (C) FACS analysis showing a high percentage of activated CD4⁺ and CD8⁺ T cells in the LN. Numbers in A and C denote the percentage of total CD4⁺ or CD8⁺ T cells. (D) CD38⁺HLA-DR⁺ T cells in the blood (red) had an effector phenotype. Numbers denote a percentage of activated CD4⁺ or CD8⁺ T cells expressing or downregulating the marker of interest. Naive (black) CD4⁺ or CD8⁺ T cells are shown as a control. All gates were set in reference to naive CD4⁺ or CD8⁺ T cells. (E) UL-25 tetramer staining in the blood on day +5 and day +270. Numbers denote the percentage of total CD8⁺ T cells. (F) Percentage of HSV-2 UL-25–specific tetramer⁺CD8⁺ T cells in the blood over time. (G) Extended phenotype analysis of UL-25 tetramer⁺CD8⁺ T cells in the blood on day 5. Green indicates UL-25 tetramer⁺CD8⁺ T cells; black indicates naive CD8⁺ T cells. Numbers indicate the percentage of tetramer⁺ (green) CD8⁺ T cells. Mean plasma levels of proinflammatory cytokines IFN-γ (H), IL-18 (I), and IL-6 (J) were elevated in the acute setting. All measurements were performed in quadruplicate. Error bars indicate the SD. Horizontal dotted line indicates the levels in pooled plasma from aged-matched healthy individuals. For all applicable graphs, the vertical dotted line indicates the time of presentation. Day, days since symptom onset. Rel Freq, relative frequency.