Figure 3.

Murine CD40L-activated B cells are comparable to mature dendritic cells (DC) in peptide presentation to CD4⁺ and CD8⁺ T-cell clones. Bone marrow DC or splenic CD40L-activated and expanded B-cell populations were generated as in Fig. 1 and loaded with 10 μg/ml MOG or MBP peptides, irradiated and cultured for 36 hr with MBP/MHC II-restricted CD4⁺ T cells (‘clone 12’) or MOG/MHC I-restricted, CD8⁺ T cells (‘clone 7’). ³H-thymidine was added and CPM incorporation determined 18–20 hr later. Data obtained from 3 independent cultures of APC are presented as means (³H-thymidine incorporation in the presence of peptide – ³H-thymidine incorporation in the absence of peptide) ± SE. Background incorporation of CD8⁺ and CD4⁺ T-cell clones cultured in the presence of APC but without peptide averaged <600 c.p.m. and <2000 c.p.m., respectively.