Figure 4.

AICD by cognate target cells. (a) AKR anti-LF⁻ PEL (k anti-d); (b) B/6 anti LF⁻ (b anti-d); (c) B/6 anti-EL4 (syngeneic) were preincubated with different partners for 15 hr before adding ⁵¹Cr-labelled targets (3 × 10⁴ cells/well). Lysis was measured after incubation for 3 hr. In the ⁵¹Cr-release assay, the ratio of effectors to targets was 2·5:1 in (a) and (b), and 10:1 in (c). The cytocidal activity roughly reflected the number of PELs which survived from the preincubation. Ratio of PEL to the cognate targets in the preincubation is as in the parenthesis; the concentration of Jo2 was 2 µg/ml.