Table 3.

Inhibited indicator allogeneic responses to Con A and CT-DNA–induced stimulatory responses^*

Con A = Concanavalin A; CT-DNA = calf thymus mammalian double-stranded DNA.

^*The technique consists of a binary set of interactive cellular responses: (1) a first phase, in which PBMCs were preincubated with medium, Con A or CT-DNA, for 48 hours, after which the cells were washed and treated with mitomycin C (“stimulatory cells”); and (2) a second phase in which equal numbers of freshly isolated homologous normal PBMCs from subject A (alone) or subjects A and B (“responder cells”) were cocultured with the mitomycin C–inactivated PBMCs from the first phase and were allowed to respond to alloantigens; 2 μCi of [³H] thymidine were added to each well during the last 24 hours of the seventh day of incubation, after which the cells were harvested and radioactivity measured as described above in the section Lymphoproliferative Assays; the lack of [³H] thymidine [³H]-TdR incorporation into the “responder cells” due to a lack of stimulation by the mitomycin C cells in the second phase was defined as a measure of suppression and was expressed as the percentage reduction of experimental from medium control values.

#Subjects A and B are two allogeneic healthy human subjects.