Figure 2

Direct alloactivation of naive and memory T cells by IFN-treated EC, fibroblasts and RPTEC. Panel A, FACS analysis of MHC class II on EC, fibroblasts and RPTEC, either untreated or following treatment with IFN for 48 and 72 h, as indicated, using mouse anti-human HLA-DR (LB3.1, solid black lines) or negative control mouse IgG (K16/16, grey lines). The expression of ICAM-1 served as a positive control (not shown). Panel B, Nave CD45RA⁺ and memory CD45RO⁺ CD4⁺ T cells were isolated from PBMC. A total of 1x10⁵ CD45RA⁺CD4⁺ T cells (white bars) or CD45RO⁺CD4⁺ T cells (black bars) were cocultured either alone (striped bars) or with 5x10⁴ allogeneic IFN-treated EC, fibroblasts or RPTEC (solid bars) for 5days. Proliferation was assessed by [³H] thymidine incorporation. Results are representative of at least 3 experiments performed in triplicate 1SD (*P<0.05) using cells from different donors and responders