FIG 4.

Asymptomatic individuals have a significantly higher proportion of polyfunctional HSV-1 gB-epitope-specific CD8⁺ T cells. (A) gB epitope-primed CD8⁺ T cells from ASYMP individuals express high levels of lytic granules compared to CD8⁺ T cells from SYMP individuals. FACS was used to determine the expression levels of GzmB, GzmK, and PFN on tetramer-gated CD8⁺ T cells specific the to gB_183–191, gB_342–350, and gB_561–569 epitopes, as described in Materials and Methods. The numbers on the top of each histogram represent mean fluorescence intensity (MFI), depicting the level of expression of each cytotoxic molecule. Numbers in bold represent the MFI for ASYMP individuals. (B and C) FACS data showing frequency of gB_561–569-specific GzmB⁺ CD8⁺ T cells in SYMP and ASYMP individuals. (D to I) Representative histograms (D and G), average MFI (E and H), and absolute numbers (F and I) of gB_561–569-specific GzmB⁺ CD8⁺ T cells and PFN⁺ CD8⁺ T cells from 10 ASYMP and 10 SYMP individuals, respectively. (J to L) Representative FACS data (J), frequencies (K), and absolute numbers (L) of gB_561–569-specific IFN-γ⁺ CD8⁺ T cells from 10 ASYMP and 10 SYMP individuals. (M to O) Representative FACS data (M), frequencies (N), and absolute numbers (O) of gB_561–569-specific CD107^a/b+ CD8⁺ T cells from 10 ASYMP and 10 SYMP individuals. (P) Summary pie charts showing the overall portions of gB epitope-specific CD8⁺ T cell functions from 10 ASYMP and 10 SYMP individuals. (Q and R) Representative FACS data (Q) and average frequencies (R) of gB_561–569-specific Ki-67⁺ CD8⁺ T cells from 10 ASYMP and 10 SYMP individuals. (S and T) Representative histogram (S), MFI (T, left panel), and absolute number (T, right panel) of gB_561–569-specific PD-1⁺ CD8⁺ T cells. Bold number represents the MFI of ASYMP individuals. The results are representative of 2 independent experiments for each individual. The indicated P values, calculated using one-way ANOVA, show statistical significance of differences between SYMP and ASYMP individuals.