Bone marrow CD34+ cells generate fewer T cells in vitro with increasing age and following chemotherapy

作者：Fritz Offner, Tessa Kerre, Magda De Smedt, Jean Plum · 发表于：British Journal of Haematology · 年份：1999 · DOI：10.1046/j.1365-2141.1999.01265.x · 被引用次数：48 · 研究领域：Hematopoietic Stem Cell Transplantation、Immunotherapy and Immune Responses、Immune Cell Function and Interaction

To assess the influence of high-dose chemotherapy and age on the intrinsic capacity of stem cells to generate T cells, CD34+ cells derived from bone marrow used in clinical transplantation were evaluated in an in vitro T-cell assay using a mouse thymic microenvironment. CD34+ cells were sorted from healthy donor and autologous back-up bone marrow after density gradient centrifugation and depletion for CD1, 3, 4, 7, 8, 19 and glycophorin A using magnetic beads. CD34+ cells were then introduced in day 14-15 fetal SCII) mouse thymus lobes by incubation in hanging drops for 48 h. After transfer to gelfoam rafts they were cultured for variable time periods. The lobes were then homogenized in a tissue grinder for flow cytometric analysis gating on human cells. These were evaluated for CD4, CD8, CD3 and HLA-DR surface expression. 51 samples were analysed and three patterns of T-cell precursor development could be observed. In pattern A no human cells could be recovered, in pattern B maturation stopped at the CD4+ CD8- CD3- pre-T-cell stage, and in pattern C maturation to double-positive CD4+ CD8+ thymocytes was reached. In 25 healthy donors under age 40 three showed pattern A, 12 pattern B and 10 pattern C, whereas in 16 healthy donors over the age 40 there were respectively four with A, seven with B and only five with C (P=0.01). In 10 patients who had previously received chemotherapy, none developed pattern C, five pattern B and five pattern A, in contrast to 15/41 pattern C, 19/4...