Fig. 2

In vitro-expanded CD8⁺CD28⁻ T cells maintain allospecific suppressive activity in vivo.a Experimental procedure: purified CD8⁺ T cells were expanded in vitro in the presence of allogenic APCs plus the combination of the cytokines IL-2, IL-7, and IL-15 for 9 days. The mixture of human cells, which were the same as the in vitro suppression assay (4 × 10⁶ human CD4⁺ T cells were first mixed with an equal number of APCs either from B-APCs or I-APCs, and then combined with 2 × 10⁶ in vitro expanded human CD8⁺CD28⁻T cells in a total volume of 1.5 ml of PBS.), were injected into abdominal cavity of NOG mice. The mice would be sacrificed after 11 days of injection. b Representative dot plots demonstrated the existence of human cells by the expression of the molecule CD45, whereas the total cell number of CD45⁺CD4⁺ cells was counted for assessing the inhibitory function exerted by in vitro-expanded CD8⁺CD28⁻ T cells. c Aggregated data from three independent experiments using different stimulator-responder pairs were shown (n = 3). d The immunohistochemical images represented human CD4⁺ and CD8⁺ T cells (As indicated by the arrow) infiltrating in the spleen and were representative of data from all animals. Magnification: × 400. (n = 3)