Characterization of HLA Cw*0602-restricted TRATKMQVI-specific T cells. (A) Staining of fresh PBMCs and in vitro expanded T cells with APC-labeled Cw*0602-TRAT tetramer. Representative data from 2 persons (for fresh PBMCs) and one polyclonal T-cell line are shown. These cells were costained with anti-CD3 and anti-CD8 antibodies. (B) HLA restriction analysis of in vitro–expanded TRAT-specific T-cell lines. Autologous LCL and allogeneic LCLs sharing 1 or more HLA class I or class II alleles were used as APCs. These cells were either coated with synthetic TRAT peptide or left uncoated and then exposed to T cells. These T cells were then analyzed for IFN-γ expression by the use of ICS assays. Data presented show the percentage of IFN-γ expressing T cells after exposure to these LCLs. (C) Effect of anti-HLA class I or class II antibody on the T-cell recognition. Peptide sensitized Cw*0602⁺ and DRB*0401⁻ or unsensitized Cw*0602⁻ and DRB*0401⁺ LCLs were exposed to TRAT-specific T cells in the presence or absence of anti-HLA class I or anti-HLA class II antibodies. After incubation, these T cells were analyzed for IFN-γ expression using ICS assays.