Cytotoxicity of NT4.2 cells against allo LCLs that share HLA-DRB1*1501 or HLA-DRBI*0405. A total of 5 × 10⁴ NT4.2 cells were incubated with 5 × 10³⁵¹Cr-labeled auto LCL cells or allo LCL cells from aplastic anemia patients and normal individuals that share HLA-DRB1*1501 or HLA-DRB1*0405, and ⁵¹Cr release was determined. Data are expressed as a mean of triplicate cultures.