Fig 4.

DENV-specific CD4⁺ and CD8⁺ T cells target distinct viral proteins. (A) Ex vivo frequency of CD4⁺ and CD8⁺ T cell epitopes in acute, postfebrile, and convalescent patients as determined by ELISPOT assay. Results are expressed as SFC relative to 10⁵ PBMCs. PF and Conv indicate postfebrile and convalescent, respectively. Bars indicate mean values. Statistics were calculated using the nonparametric, two-tailed Mann-Whitney test. The distribution of CD4⁺ (B) and CD8⁺ (C) T cell epitopes across the DENV proteins is analyzed in 27 patients. The differential recognition of structural/surface proteins versus nonstructural proteins in each subset was compared using a two-tailed Fischer's exact test. Skewing of the CD4⁺ response toward recognition of structural/surface proteins and of the CD8⁺ response toward recognition of nonstructural proteins was statistically significant (P < 0.0001).