Figure 4

Phenotypic assessment of the CD8 ⁺ CD107a ⁺ T cell subsets using the FACS analysis. The quantities of CD107a expressing cells were analyzed from the CD8⁺ T cell subset with different combinations of CD45RA and CCR7 surface markers after the PPD stimulation (A). The phenotypic distribution of T_N, T_CM, T_EM and T_EMRA cell subsets within the CD8⁺CD107a⁺ T cell pool was assessed in different study groups. The T_EM phenotype predominated in the TB., LTBI., Surg. and Part. groups whereas in the BCG vaccinees’ group the predominat subset was T_N (B). The percentages of positivity for CD107a, the degranulation factor, within each phenotypic subpopulation in different study groups was assessed. This marker of cell activation was most prevalent within the T_CM cell subpopulation throughout all the study cohort (C). The responses from non-stimulated cells were subtracted from the PPD responses. Three samples from each group were tested, and the means with corresponding ranges are shown for T_N, T_CM, T_EM and T_EMRA cell subsets.