FIG. 4.

Effect of depletion of CD8⁺ or CD4⁺ cells on IFN-γ production. PBMC, CD8-depleted PBMC, and CD4-depleted PBMC from three healthy tuberculin reactors were cultured with M. tuberculosis for 72 h. The frequency of IFN-γ-producing cells per 10⁵ cells was determined by ELISPOT (A), and IFN-γ concentrations in supernatants were measured by enzyme-linked immunosorbent assay (B). Mean values and standard errors are shown.