Shen Bin, Zhang Yu, Dai Wei, Ma Yupo, Jiang Yongping
Biopharmaceutical R&D Center, Chinese Academy of Medical Sciences & Peking Union Medical College, 277 Qingqiu Street, Suzhou, 215126, China.
Environmental Medicine, NYU Langone Medical Center, Tuxedo, NY, 10987, USA.
Stem Cell Res Ther. 2016 Oct 20;7(1):152. doi: 10.1186/s13287-016-0413-1.
Hematopoietic CD34 stem cells are widely used in the clinical therapy of complicated blood diseases. Stem cell factor Sall4B is a zinc finger transcription factor that plays a vital role in hematopoietic stem cell expansion. The purpose of our current study is to further evaluate how Sall4B might affect the expansion of CD34 cells derived from nonhuman primates.
Sall4B was overexpressed in nonhuman primate bone marrow-derived CD34 cells via a lentiviral transduction system. The granulocyte-erythrocyte-macrophage-megakaryocyte colony-forming unit (CFU) assay evaluated the differentiation potential of primate CD34 cells that were expanded with Sall4B. Furthermore, an in-vivo murine system was employed to evaluate the hematopoietic potential of primate Sall4B-expanded CD34 cells.
Overexpression of Sall4B promoted ex-vivo nonhuman primate CD34 cell expansion by 9.21 ± 1.94-fold on day 9, whereas lentiviral transduction without Sall4B expanded cells by only 2.95 ± 0.77-fold. Sall4B maintained a significant percentage of CD34 cells as well. The CFU assay showed that the Sall4B-expanded CD34 cells still possessed multilineage differentiation potential. A study using nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice in vivo revealed that Sall4B led to an increase in the number of repopulating cells and the 9-day-old Sall4B-transduced CD34 cells still possess self-renewal and multilineage differentiation capacity in vivo, which are similar stemness characteristics to those in freshly isolated primate bone marrow-derived CD34 cells.
We investigated the expansion of nonhuman primate bone marrow-derived CD34 cells using the Sall4B lentiviral overexpression approach; our findings provide a new perspective on mechanisms of rapid stem cell proliferation. The utilization of Sall4B to expand CD34 cells on a large scale through use of suitable model systems would prove helpful towards preclinical trials of autologous transplantation.
造血CD34干细胞广泛应用于复杂血液疾病的临床治疗。干细胞因子Sall4B是一种锌指转录因子，在造血干细胞扩增中起关键作用。我们当前研究的目的是进一步评估Sall4B如何影响源自非人灵长类动物的CD34细胞的扩增。
通过慢病毒转导系统在非人灵长类动物骨髓来源的CD34细胞中过表达Sall4B。粒细胞-红细胞-巨噬细胞-巨核细胞集落形成单位（CFU）试验评估了用Sall4B扩增的灵长类CD34细胞的分化潜能。此外，采用体内小鼠系统评估灵长类Sall4B扩增的CD34细胞的造血潜能。
Sall4B的过表达在第9天促进了体外非人灵长类CD34细胞扩增9.21±1.94倍，而无Sall4B的慢病毒转导仅使细胞扩增2.95±0.77倍。Sall4B也维持了相当比例的CD34细胞。CFU试验表明，Sall4B扩增的CD34细胞仍具有多系分化潜能。一项在体内使用非肥胖糖尿病/严重联合免疫缺陷（NOD/SCID）小鼠的研究表明，Sall4B导致再填充细胞数量增加，且9日龄经Sall4B转导的CD34细胞在体内仍具有自我更新和多系分化能力，这些干性特征与新鲜分离的灵长类动物骨髓来源的CD34细胞相似。
我们使用Sall4B慢病毒过表达方法研究了非人灵长类动物骨髓来源的CD34细胞的扩增；我们的发现为干细胞快速增殖机制提供了新的视角。通过使用合适的模型系统利用Sall4B大规模扩增CD34细胞将有助于自体移植的临床前试验。
