Figure 2.

Detection of P1A:L^d epitope in spleen cells by direct cytotoxicity assay (a) or proliferation assay (b). (a) Direct cytotoxicity of P1CTL to BALB/c spleen cells which were activated by LPS, Con A, or anti-CD3 mAb. Viable cells were isolated, labeled with ⁵¹Cr, and used as target cells. Macrophage P388D1 was pulsed with either P1A (P1A) or an unrelated K^d-binding peptide (KdP) and used as control. (b) Proliferation of transgenic T cells in response to T-depleted spleen antigen–presenting cells. T-depleted, BALB/c spleen cells were cultured with either medium or LPS for 16 h. Viable cells were isolated by centrifugation through a Ficoll-hypaque medium, washed five times with PBS, irradiated (2,000 rads), and used as stimulator cells. Transgenic spleen T cells from N2 of BALB/ cxSW TCR-TG founders were used as responder. Data shown were cpm incorporated by T cells when stimulated with activated APC (cpm[T+APC-A]) or resting APC (cpm[T+APC-R]). Sum of cpmT (T cells cultured alone) plus cpm– APC (APC cultured alone) was used as the negative control. Data shown were means of six replicates and the standard deviations.