FIG. 4.

Frequencies of IFN-γ-secreting cells, as assessed by ELISPOT assay. CSFMCs and PBMCs were expanded for 2 weeks with PHA and then assessed for frequency of IFN-γ SFC to HIV-specific optimal class I peptides by ELISPOT assay. Numbers of peptides tested and numbers with IFN-γ responses are listed in Table 3. (A) Relationship between SFC frequencies among ex vivo expanded CD8⁺ cells from CSF and ex vivo expanded CD8⁺ cells from blood. (B) Relationship between SFC frequencies among ex vivo expanded CD8⁺ cells from CSF and unexpanded CD8⁺ cells from blood. The diagonal dashed line represents the line of unity. The vertical and horizontal dashed lines represent lower limits of quantitation. The P values are derived from a two-tailed Wilcoxon matched-pairs t test.