Naturally occurring IFN-I cannot induce CD45RO to CD45RA reversion in antigen-specific T cells. CD45RA and CD45RO expression was determined in total CD8⁺ T cells (A) and EBV tetramer⁺ T cells gated on total CD8⁺ T cells (B) isolated from the same patient with AIM. CD45RA and CD45RO expression was also examined in freshly isolated antigen-specific T cells (C) and CD8⁺ tetramer⁺ T cells specifically activated and expanded in culture for 1 month (D). Cell-cycle progression was determined in activated CD8⁺ tetramer⁺ T cells by 7AAD staining (E). Activated virus-specific T cells were cultured with fibroblasts for 14 days at which point CD45RO expression (F) and 7AAD staining (G) were assessed by flow cytometric analysis. These results are representative of 4 separate experiments. (A-D, F) Numbers refer to the percentage of cells found in each quadrant.