Suppression by the in vitro expanded CD8⁺CD28⁻ T cells is restricted by donor HLA class I antigens.

Suppression assays were set up as described in Figure 2, with the exception that the stimulator APCs for CD4⁺ proliferation were from either the priming donor (B-_APC), an indifferent donor (I-_APC, HLA-A, B and DR fully mismatched with donor B), or a partially matched donor (C-_APC, who shared identical HLA class I, but not class II antigens, with donor B). Proliferation of the CD4⁺ cells was measured by CFSE dilution. Data shown are representative of three independent experiments using three pairs of donors B, C and I. Table 1 provides one example of the HLA class I and class II antigen typing of individuals B, C, and I used for one of three such experiments.