Figure 5. Cell surface phenotype of PHA-activated CD8 Treg.

(A) Representative histograms for cell surface antigen expression on PHA activated CD8 Treg (CD56^pos) and CD8 Tcon (CD56^neg). CD56^pos and CD56^neg cells isolated from PBMC were stimulated with PHA and cultured in the presence of feeder cells for 8 days before being analyzed for cell surface marker expression as described in Materials and Methods. Data shown are from one of 5 representative healthy donors. (B) Activated CD56^pos cells maintained high expression of CD56 and CD94 and lower expression of CD62L and CD27. CD8 Treg (CD56^pos) and CD8 Tcon (CD56^neg) cells isolated from PBMC were stimulated with PHA and cultured in the presence of feeder cells for 9 to 16 days before being analyzed for intensity of expression of CD56, CD62L, CD27 and CD94 cell surface antigens. p-value was calculated with unpaired two-tailed Student’s t-test. Mean and standard deviation are shown (n = 5).