Cell-surface molecule profile of LC15 cells. (A) LC15 cells were examined for common T-lymphocyte markers at 2 weeks and 8 months after IL-2 withdrawal. Cells were stained with fluorescent-labeled antibodies against CD4, CD8, CD25, CD28, CD45RA, CD45RO, CD56, and CD62L. Lymphocytes were subsequently analyzed by FACS. (B) Activation marker profiles of OKT3-stimulated CD8⁺ T cells cultured with IL-15 (10 ng/mL) and 8-month cultured LC15 cells. OKT3-stimulated CD8⁺ T cells were cultured for 2 weeks in media containing IL-2 prior to analysis. LC15 cells were cultured for 8 months after IL-2 withdrawal. Cells were double stained with CD3 and either CD2, CD5, CD7, or CD38 prior to analysis by FACS.