Responses directed against autologous LCL are primarily made up memory T cells. PBMCs from 10 healthy EBV-seropositive patients were incubated with autologous LCL (PBMC/LCL = 10:1) for 20 hours followed by cell surface staining for CD8⁺ T cells (A) or CD4⁺ T cells (B) and phenotypic markers of memory, and intracellular IFNγ. Memory phenotypes were defined as following: naive: CD45RA⁺ CD62L⁺ CCR7⁺; central memory: CD45RA⁻ CD62L⁺ CCR7⁺; effector memory: CD45RA⁻ CD62L⁻ CCR7⁻; CD8⁺ EMRA⁺: CD45RA⁺ CD62L⁻ CCR7⁻. (C) Responding CD8⁺ and CD4⁺ T cells are mostly memory cells. (D,E) Larger fractions of effector memory and EMRA⁺ CD8⁺ T cells (D) respond to autologous LCL, whereas effector memory and naive CD4⁺ T cells (E) respond to autologous LCL.