Figure 7

HLA-universal megakaryocytes (MKs) are protected from anti-HLA antibody-mediated cytotoxicity. (A) Complement-dependent cytotoxicity (CDC) assays were performed with nontransduced and shNS- or shβ2m-expressing MKs, using complement-fixing anti-HLA antibodies. Specific anti-HLA-A*02 or anti-HLA-A*29 antibodies were used. An antibody recognizing HLA-A*23/24 (not expressed on the MKs) was used as negative control. Cell lysis rates were measured by flow cytometry. (B) Antibody-dependent cellular cytotoxicity (ADCC) assays were performed with antibodies specific for HLA-A*02 and HLA-ABC. Nonspecific HLA-A*23/24 antibody served as a negative control. Luciferase activity was determined and is shown in relative luminescence units (RLU). The graphs display means and SD in three independent experiments. ***p ≤ 0.001, **p ≤ 0.01, *p ≤ 0.05.