Ex vivo expansion CD34+/AC133+ - selected autologous peripheral blood progenitor cells (PBPC) in high-risk breast cancer patients receiving intensive chemotherapy

AC133 antibody provides an alternative to CD34 for the selection and characterization of cells necessary for engraftment in transplant situations. We studied the effect of stem cell factor (SCF), interleukin 3 (IL-3) and interleukin 11 (IL-11) on the ex vivo expansion of human CD34⁺/AC133⁺ progenitors isolated from leukapheresis products from chemotherapy plus granulocyte-colony-stimulating factor (G-CSF) -mobilized adult donors. MiniMACS AC133⁺ isolated cells contained a mean of 85% (80-90) AC133⁺ cells. Enriched AC133⁺ cells co-expressed CD34⁺ 80%, CD71^low 36.6 % and CD33⁺ 6.6 %. After a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11, the number of cells increased 19 times. These cells expressed a mean 12% CD34⁺ and 74% CD71⁺ (23% CD 71^high) and 59% CD33⁺. This means that the absolute number of CD34⁺ cells increased slightly, the number of CD33⁺ increased 100 times and cells with high density CD71^high (23%) appeared. These cells represent the cells committed to erythroid differentiation. The increase in the number of CFU-GM with various combinations of cytokines SCF + Il-3 + IL-11 will be discussed. The number of CFU-GM in culture after a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11 increased 45 times.