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Full-Text Articles in Cell and Developmental Biology
Investigation Of Murine Spleen As A Niche For Hematopoiesis., Jonathan Tan, Helen O'Neill
Investigation Of Murine Spleen As A Niche For Hematopoiesis., Jonathan Tan, Helen O'Neill
Jonathan Tan
Background Spleen as a lymphoid tissue is specialized for monitoring blood and mounting immunity against blood-borne antigens. Antigen-presenting cells present in spleen commonly develop from bone marrow-derived precursors that enter blood circulation. However, a distinct splenic myeloid antigen-presenting cell subset described in this laboratory, namely “dendritic-like cells” (L-DC), has been hypothesized not to share a bone marrow origin. Methods In this study, the presence of endogenous hematopoietic progenitors in spleen was investigated by transplanting intact spleen into allotype-distinct recipients and monitoring development of progeny cells in grafted tissues. Results Successful engraftment of donor spleens was achieved for up to 4 …
Gene Signature Of Stromal Cells Which Support Dendritic Cell Development., Geneviève Despars, Pravin Periasamy, Jonathan Tan, Janice Abbey, Terence O'Neill, Helen O'Neill
Gene Signature Of Stromal Cells Which Support Dendritic Cell Development., Geneviève Despars, Pravin Periasamy, Jonathan Tan, Janice Abbey, Terence O'Neill, Helen O'Neill
Jonathan Tan
Spleen stromal cells are critical determinants of dendritic cell (DC) development in spleen. The spleen stromal line, namely STX3, supports DC differentiation in vitro from overlaid bone marrow cells while the lymph node stromal line, namely 2RL22, does not. Here we have characterised the hematopoietic support capacity of each stroma, and analyzed lineage origin of the stromal cell lines by gene profiling using microarrays. Stromal co-culture experiments were performed using bone marrow cells as a source of hematopoietic progenitors. A characteristic immature myeloid-like CD11c+CD11b+CD86+MHC-II−/loB220−CD8α− DC is produced after 14 days in STX3 cocultures, while 2RL22 cocultures produce only monocyte/macrophage-like cells. …
Splenic Stromal Niches Support Hematopoiesis Of Dendritic-Like Cells From Precursors In Bone Marrow And Spleen., Pravin Periasamy, Jonathan Tan, Kristin Griffiths, Helen O'Neill
Splenic Stromal Niches Support Hematopoiesis Of Dendritic-Like Cells From Precursors In Bone Marrow And Spleen., Pravin Periasamy, Jonathan Tan, Kristin Griffiths, Helen O'Neill
Jonathan Tan
Objective The aims of this study are to test the ability of stromal cells from murine spleen to support hematopoiesis, to define the tissue source of precursors that seed these hematopoietic niches, and to determine the type of cells produced. Materials and Methods Cloned isolates of murine spleen stroma have been developed that support hematopoiesis. Analysis has been investigated in terms of tissue source of progenitors. Type and number of cells produced were analyzed by flow cytometry. Results Hematopoietic precursors that seed cocultures exist in spleen and bone marrow (BM), but not thymus. Cell production is highest if overlay cells …
Hematopoiesis Of Immature Myeloid Dendritic Cells In Stroma-Dependent Spleen Long-Term Cultures Occurs Independently Of Nf-Kb/Relb Function, Jonathan Tan, Keping Ni, Fei Le, Helen O'Neill
Hematopoiesis Of Immature Myeloid Dendritic Cells In Stroma-Dependent Spleen Long-Term Cultures Occurs Independently Of Nf-Kb/Relb Function, Jonathan Tan, Keping Ni, Fei Le, Helen O'Neill
Jonathan Tan
Objective The nuclear factor-κB (NF-KB)/RelB transcription factor plays an essential role in development of some dendritic cell (DC) subsets in mice. In this laboratory, immature myeloid DC are produced in vitro in a stroma-dependent murine spleen long-term culture (LTC) system. In LTC, DC differentiate from hematopoietic progenitors maintained within the stromal cell matrix. Expression and function of RelB in development of LTC-DC has been investigated, with a view to assessing the relationship between DC produced in this system and other known subsets of DC. Materials and Methods RelB expression by LTC-DC was confirmed by detection of protein by Western blotting, …
Maturation Requirements For Dendritic Cells In T Cell Stimulation Leading To Tolerance Versus Immunity, Helen O'Neill, Jonathan Tan
Maturation Requirements For Dendritic Cells In T Cell Stimulation Leading To Tolerance Versus Immunity, Helen O'Neill, Jonathan Tan
Jonathan Tan
The model that dendritic cell (DC) "maturation" describes the change from an immature, antigen-capturing cell to a mature, antigen-presenting cell is well-established. Classification of DCs in terms of function has been problematic previously. It is therefore proposed that mature and not immature DCs are responsible for antigen presentation and stimulation of T cells. Furthermore, DC antigen presentation to T cells can have two outcomes: tolerance or immunity. The particular outcomes appear to be determined by the activation state of the mature DC. DCs can be activated by a range of environmental stimuli or "danger signals". Here, the hypothesis is advanced …