Assessment of telomere length in CD45RA⁺ and CD45RO⁺ EBV-specific CD8⁺ T cells.

CD8⁺, CD45RA⁺ and CD8⁺, CD45RO⁺ T cells were first isolated by magnetic bead depletion from PBMCs of healthy persons who recovered from AIM. These cells were then stained with EBV lytic epitope-specific tetramers coupled to Cy5 and the PNA telomeric probe coupled to FITC as described in “Materials and methods.” We gated on tetramer-positive populations, and the telomeric staining (median fluorescence intensity) of total CD8⁺CD45RA⁺, lytic epitope-specific CD8⁺ T cells that express CD45RA⁺ (Tet RA) or CD45RO⁺ (Tet RO) in 5 different persons who had recovered from AIM were investigated. Each person is represented by one symbol, and the telomere staining of the 3 different subsets for that subject is shown. The significance of the results was determined by the Student t test.