Quantitative studies on concanavalin A-induced, TCGF-reactive T cells. I. Correlation between proliferation and lectin-dependent cytolytic activity

A limiting dilution assay was used to determine the frequencies of T cells that could be induced to proliferate and kill by Con A and TCGF. The frequency of proliferating cells was 1 in 5 nylon wool-purified spleen cells and 1 in 7 normal lymph node cells. The frequencies in the same cell populations of lectin-dependent killer cell precursors were 1 in 5 and 1 in 9, respectively. Even at limiting numbers of T cells seeded per culture, very few cultures proliferated without showing cytotoxic activity. Thus, under these conditions Con A and TCGF, preferentially if not exclusively, activate T cells that will kill in the presence of PHA. This experimental system can be used for estimating the repertoires of specific CTL-precursors activated by Con A and expanded in TCGF.