Shatry Alwi M, Levy Robert B
Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, FL 33101, USA.
Stem Cells Dev. 2004 Aug;13(4):390-9. doi: 10.1089/scd.2004.13.390.
The lymphohematopoietic function of the spleen in mice varies dependent on age and hematopoietic requirements. A method was developed to study splenic repopulation of mature and progenitor cell populations by grafting neonatal or adult spleen tissue under the renal capsule of splenectomized mice. Two weeks following implant of irradiated syngeneic neonatal spleens into B6-Ly 5.1 or B6-gfp recipients, host lymphoid (B220(+), CD4/8(+)) and myeloid cells (CD11b(+)) had repopulated the splenic grafts and constituted the majority of cells contained in these heterotopic implants. Notably, the percentage of lymphoid and myeloid cells approximated adult levels in contrast to preimplant neonatal spleen levels. This observation indicated relatively rapid repopulation of the grafted tissue by adult host cells and suggests that the repopulation patterns were regulated by the host. Three months post-implantation, the cell composition in the graft remained comparable to adult levels. Microscopic examination demonstrated normal splenic architecture including follicles and red pulp. Lymphocytes within the graft were functional as indicated by their proliferation in response to lipopolysaccharide (LPS) and concanavalin A (ConA) stimulation. Progenitor cell activity determined by colony-forming unit interleukin-3 (CFU-IL-3) levels was also present in these grafts. Splenic implants were then assessed in transplant models following lethal irradiation and syngeneic or allogeneic bone marrow transplantation (BMT). Two weeks post-BMT, adult splenic tissue implants contained donor-derived B cells, T cells, and myeloid cell populations. As typically detected in the host spleen post-BMT, the grafted tissue also contained elevated levels of donor progenitor cells. By 3 months post-BMT, CFU-IL3 levels in the graft reflected the decreased levels characteristic of adult levels. The functional integrity of post-transplant splenocytes in the implants was also demonstrated by mitogenic responsiveness. In summary, this method should provide a useful model for the transfer of the splenic microenvironment to study the biology of the spleen in non-transplant and BMT settings.
小鼠脾脏的淋巴造血功能因年龄和造血需求而异。我们开发了一种方法，通过将新生或成年脾脏组织移植到脾切除小鼠的肾包膜下，来研究成熟细胞群和祖细胞群的脾脏再填充情况。将经辐照的同基因新生脾脏植入B6-Ly 5.1或B6-gfp受体两周后，宿主淋巴细胞（B220(+)、CD4/8(+)）和髓样细胞（CD11b(+)）已重新填充脾脏移植物，并构成这些异位植入物中所含细胞的大部分。值得注意的是，与植入前新生脾脏水平相比，淋巴细胞和髓样细胞的百分比接近成年水平。这一观察结果表明成年宿主细胞对移植组织的再填充相对较快，并表明再填充模式受宿主调节。植入后三个月，移植物中的细胞组成仍与成年水平相当。显微镜检查显示脾脏结构正常，包括滤泡和红髓。移植物中的淋巴细胞具有功能，这通过它们对脂多糖（LPS）和刀豆球蛋白A（ConA）刺激的增殖来表明。通过集落形成单位白细胞介素-3（CFU-IL-3）水平测定的祖细胞活性在这些移植物中也存在。然后在致死性辐照和同基因或异基因骨髓移植（BMT）后的移植模型中评估脾脏植入物。BMT后两周，成年脾脏组织植入物包含供体来源的B细胞、T细胞和髓样细胞群。如在BMT后宿主脾脏中通常检测到的那样，移植组织中供体祖细胞水平也升高。到BMT后3个月，移植物中CFU-IL3水平反映出成年水平特有的降低水平。植入物中移植后脾细胞的功能完整性也通过有丝分裂反应性得到证明。总之，该方法应为脾脏微环境的转移提供一个有用的模型，以研究非移植和BMT环境下脾脏的生物学特性。
