Fig. 6: Generation of conventional T-cells that secrete cytokines.

a Nonspecific TCR stimulation using anti-CD3 monoclonal antibodies with IL-2 administration induced maturation of DP to CD8SP T-cells. These cells predominantly expressed CD8αβ heterodimers and high levels of CD27 and CD45RA. A smaller proportion of CD8SP expressed CCR7 than postnatal thymocytes. b A small population of CD4SP T-cells were present and fewer of these cells expressed CD27 and CCR7 than ETN-generated CD8SP or CD4SP postnatal thymocytes. Shown are means from n = 3 UCB donors and n = 3 postnatal thymus donors. c Further stimulation using PMA and ionomycin resulted in secretion of IFNγ with some cells also secreting IL-2. Fewer postnatal thymocytes secreted IFNγ than generated T-cells and none secreted both IFNγ and IL-2. Peripheral T-cells secreted high levels of both IFNγ and IL-2. d The frequency of IFNγ secreting cells was comparable between ETN-generated and peripheral T-cells and markedly greater than postnatal thymocytes. The frequency of IL-2 secreting cells was much lower in ETN-generated T-cells and postnatal thymocytes than peripheral T-cells. All cytokine secretion is from viable CD3⁺ cells. c, d from n = 3 UCB donors. One donor each of postnatal thymocytes and peripheral T-cells are shown with n = 5 technical replicates.