Fig. 7. FSS supernatant is a strong inhibitor of T cell proliferation. (A) T cell proliferation assays were carried out using 10⁴ OT-II CD4⁺ T cells stimulated with 10⁴ of different putative APCs (BM derived macrophages and DCs, FSS derived macrophages and FSS) in the absence (white bars) or presence (black bars) of 1 µg/ml of OVA_323-336 peptide (pOVA) for 4 days. (B) Supernatants from serially diluted putative APC (10 to 10⁵ cells), from the experiments shown in A, were added to a new proliferation assay performed with 10⁴ OT-II CD4⁺ T cells stimulated with 10⁴ BM-derived DCs. T cell proliferation was measured by [³H]-thymidine incorporation for a period of 18 hours and is expressed as the mean of cpm of duplicates.