ABIS-45RC chimeric anti-human CD45RC mAb induces cell death of CD45RC^highT cells. (A) Expression levels of CD45RC using ABIS-45RC mAb on different human leukocyte subsets. Staining with ABIS-45RC was realized in whole blood (EDTA) from healthy volunteers after lysis of red blood cells before cytometry analysis. Cells were first gated on morphology, singlet cells, and live cells. Mean expression ± SEM of CD45RC^high, CD45RC^low, and CD45RC⁻ on different cell types (n = 3) (1 experiment). (B) Human PBMCs incubated at 37°C with 10 µg/mL ABIS-45RC or isotype control mAbs were stained with annexin V and DAPI to analyze apoptosis. Results are expressed as relative proportion of annexin V⁺ cells among CD3⁺ cells (left) or CD3⁻ cells (right) for 1 to 18 hours. A representative staining of ABIS-45RC on the different populations analyzed is shown (bottom). **P < .01.