Department of Medicine, University of Alabama at Birmingham, United States; Department of Epidemiology, University of Alabama at Birmingham, United States.
Transpl Immunol. 2013 Mar;28(2-3):112-9. doi: 10.1016/j.trim.2013.01.001. Epub 2013 Jan 17.
Bone marrow reconstitution is utilized as a tool for disease treatment and as a research technique to elucidate the function of bone marrow derived cells. Clinically successful engraftment is indicated by the development of a functioning immune repertoire. In research, reconstitution is considered successful if >85% of splenic leukocytes are of donor origins. Previous work suggests that splenic reconstitution may not be indicative of reconstitution in the mucosa. We sought to evaluate mucosal reconstitution in animals following a standard bone marrow eradication and reconstitution technique. Bone marrow was harvested from adult B6.SJL donor mice (CD45.1) and injected via either the retro-orbital or intraperitoneal route into lethally irradiated B6 (CD45.2) adult or neonatal recipients respectively. The expression of CD45 by flow cytometry was used to calculate reconstitution with respect to immune compartment and cell type. In reconstituted adult animals 93.2±1.5% of splenic leukocytes expressed the donor CD45.1 antigen thus meeting the standard definition of reconstitution, however only 58.6±13.6% of intestinal lamina propria lymphocytes and 52.4±16.0% of intestinal intraepithelial lymphocytes were of donor origin, confirming splenic reconstitution fails to represent peripheral immune reconstitution. T-cells in the gastrointestinal tract are the most poorly reconstituted, while B-cells appear to be almost universally replaced by donor cells. The inadequate mucosal reconstitution was not corrected by evaluating later time points or by performing the bone marrow transfer during the neonatal period. This demonstration that substantial host T-cells remain in the intestinal mucosa after a "successful" bone marrow transplantation should cause a re-evaluation of data from research bone marrow chimera experiments, as well as the mechanisms for complications after clinical bone marrow transplantation.
骨髓重建被用作治疗疾病的工具和研究技术，以阐明骨髓来源细胞的功能。临床成功的植入表现为免疫功能的发展。在研究中，如果脾脏白细胞中有>85%来源于供体，则认为重建成功。先前的工作表明，脾脏重建可能不能指示黏膜的重建。我们试图评估在标准骨髓消除和重建技术后动物的黏膜重建。从成年 B6.SJL 供体小鼠（CD45.1）中采集骨髓，并通过眶后或腹腔途径分别注射到致死性辐射的 B6（CD45.2）成年或新生受者体内。通过流式细胞术检测 CD45 的表达，计算免疫区室和细胞类型的重建情况。在重建的成年动物中，93.2±1.5%的脾脏白细胞表达供体 CD45.1 抗原，因此符合重建的标准定义，然而，只有 58.6±13.6%的肠固有层淋巴细胞和 52.4±16.0%的肠上皮内淋巴细胞来源于供体，证实脾脏重建不能代表外周免疫重建。胃肠道中的 T 细胞重建最差，而 B 细胞似乎几乎完全被供体细胞取代。通过评估稍后的时间点或在新生儿期进行骨髓转移，都不能纠正不完全的黏膜重建。这表明在“成功”骨髓移植后，大量宿主 T 细胞仍存在于肠黏膜中，这应该重新评估来自研究骨髓嵌合体实验的数据，以及临床骨髓移植后并发症的机制。
