Inhibition of intracellular BCG growth by specific T-cell subsetsa

Effector cellsNo. of exptsUridine uptake (median ± SD)% Inhibition (mean ± SE)
Medium-rested total PBMC7344,103 (± 140,985)
BCG-expanded total PBMC7231,324 (± 95,320)b28 (± 6)
BCG-expanded CD4+ T cells7276,118 (± 120,676)12 (± 13)
BCG-expanded CD8+ T cells4156,744 (± 80,462)c36 (± 11)
BCG-expanded γδ T cells5179,783 (± 26,102)b31 (± 10)
  • a BCG-infected macrophages were incubated with total rested PBMC, total PBMC expanded with live BCG, and T-cell subsets enriched from BCG-expanded PBMC (10:1 effector-to-target ratio). After 3 days of coculture, mammalian cells were disrupted with saponin and residual viable BCG were counted by tritiated uridine uptake. Percent inhibition of intracellular BCG growth was calculated comparing BCG-expanded effector cells with medium-rested effector cells as described in Materials and Methods.

  • b P < 0.05 by the Wilcoxon matched-pairs test compared with BCG growth in cultures incubated with rested total PBMC.

  • c BCG-expanded CD8+ T cells versus medium-rested total PBMC. P = 0.06.