Figure 4.

Role of CD48 in allo-mixed lymphocyte reactions. In A, cultures were constructed by using 2 × 10⁵ T cells from BALB/c wild-type mice (WT B/c) as responders. Irradiated (3,000 rads) spleen cells from C57BL/6 wild-type mice (WT B6, ○), CD48^−/− C57BL/6 mice (KO B6, •), or BALB/c wild-type mice (WT B/c, ⋄) were added as stimulators in the numbers indicated on the x axis. In B, irradiated (3,000 rads) spleen cells from BALB/c wild-type mice (WT B/c) were used as stimulators as indicated on the x axis. Cultures were set up by using T cells from C57BL/6 wild-type mice (WT B6, □), CD48^−/− C57BL/6 mice (KO B6, ■), or BALB/c wild-type mice (B/c WT, ⋄) were added as responders. All cultures were set up in triplicate and were pulsed with 1 μCi (37 kBq) of [³H]thymidine per well for the last 18 hr of the 5-day incubation period to assay for T cell proliferation. Qualitatively similar results were obtained when T cell proliferation was measured on days 4, 6, and 7 after initiation of the culture (data not shown). Results are representative of five independent experiments