The localisation of B lymphocyte precursor cells in mouse bone marrow and their associations with stromal reticular cells and macrophages have been investigated by in vivo radioimmunolabeling combined with light and electron microscope radioautography. Many early B lineage cells expressing the B220 glycoprotein prior to the expression of surface immunoglobulin and those regenerating after sub-lethal $ gamma$-irradiation, were located in bone-associated regions of femoral marrow. Labeled B220$ sp*$ lymphoid cells of undifferentiated morphology were closely associated with complex cytoplasmic processes of stromal reticular cells. The binding of a monoclonal antibody raised against a B lymphocyte-supportive stromal cell line (mAb KMI6), was highly restricted to the interface between stromal cells and undifferentiated lymphoid cells. The VCAM-1 specific mAb M/K-2, labeled electron-dense stromal cells that contacted lymphoid cells and a variety of other hemopoietic cell lineages. Within the bone marrow of normal mice there was evidence of death of B220$ sp+$ B lineage cells by apoptosis and their removal by macrophages. Cell loss, apoptosis and macrophage deletion of B precursor cells were greatly enhanced in E$ mu$-myc transgenic mice. The results reveal a complex in vivo microenvironmental organisation of B lymphocytopoiesis characterised by intimate interactions with stromal reticular cells and macrophages which regulate the development of precursor B cells and determine the ultimate output of B lymphocytes from the bone marrow.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41346 |
| Date | January 1993 |
| Creators | Jacobsen, Karen Ann |
| Contributors | Osmond, Dennis G. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Anatomy and Cell Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001351436, proquestno: NN91909, Theses scanned by UMI/ProQuest. |
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