T cells from healthy subjects and from IM subjects express the 3 chains of the IL-15 receptor. (A) Expression of IL-15Rα on PBLs. Representative staining profiles for IL-15Rα expression on CD4⁺ and CD8⁺ T cells from 1 long-term post-IM subject (IM10) and 1 healthy subject (HS09). Analysis was restricted to the lymphocyte population (ie, excluding monocytes) by gating on cell size and 2 different antibodies (huIL-15R-M162 and sc-9172) were used to validate the staining. These results are representative of those obtained in experiments on 11 post-IM subjects studied between 1 and 20 years after diagnosis, and 12 healthy carriers. (B,C) Summary of IL-15Rα expression on CD4⁺ T and CD8⁺ T cells in the post-IM subjects and healthy subjects. (B) Table results are expressed as the percentage of IL-15Rα–positive cells, stained with the anti–IL-15Rα antibody sc-9172, in CD4⁺ T and CD8⁺ T populations from 11 post-IM subjects and 12 healthy subjects. (C) Scatterplots of IL-15Rα on CD4⁺ T cells (left panel) and CD8⁺ T cells (right panel). Horizontal lines represent the median value for each group. Statistical analysis was performed using the Student t test and shows no significant differences between CD4⁺ T cells or between CD8⁺ T populations. NS indicates not significant.