FIG. 4.

Precursors of cytotoxic T lymphocytes in the spleen 20 weeks after rectal or intradermal administration of BCG to macaques. Cells were collected from spleen biopsies 20 weeks after immunization of macaques (n = 3) via the rectal (▴) or intradermal (▾) route. The cells were stimulated by incubating in vitro in the presence of PPD (10 μg/ml) for 5 days. Their cytotoxic activity was tested against syngenic macrophages obtained from bronchoalveolar lavages, which had taken up BCG by phagocytosis 24 h before the assay. The results are representative of two different experiments. Error bars, standard deviations.