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Full-Text Articles in Medicine and Health Sciences
Impact Of The C-Mybe308g Mutation On Mouse Myelopoiesis And Dendritic Cell Development, Peter Papathanasiou, Sawang Petvises, Ying-Ying Hey, Andrew C Perkins, Helen C O'Neill
Impact Of The C-Mybe308g Mutation On Mouse Myelopoiesis And Dendritic Cell Development, Peter Papathanasiou, Sawang Petvises, Ying-Ying Hey, Andrew C Perkins, Helen C O'Neill
Helen O'Neill
Booreana mice carrying the c-Myb308G point mutation were analyzed to determine changes in early hematopoiesis in the bone marrow and among mature cells in the periphery. This point mutation led to increased numbers of early hematopoietic stem and progenitor cells (HSPCs), with a subsequent reduction in the development of B cells, erythroid cells, and neutrophils, and increased numbers of myeloid cells and granulocytes. Myelopoiesis was further investigated by way of particular subsets affected. A specific question addressed whether booreana mice contained increased numbers of dendritic-like cells (L-DC subset) recently identified in the spleen, since L-DCs arise in vitro by direct …
Redefining Myeloid Subsets In Murine Spleen, Ying-Ying Hey, Jonathan K H Tan, Helen C O'Neill
Redefining Myeloid Subsets In Murine Spleen, Ying-Ying Hey, Jonathan K H Tan, Helen C O'Neill
Helen O'Neill
Spleen is known to contain multiple dendritic and myeloid cell subsets, distinguishable on the basis of phenotype, function and anatomical location. As a result of recent intensive flow cytometric analyses, splenic dendritic cell (DC) subsets are now better characterized than other myeloid subsets. In order to identify and fully characterize a novel splenic subset termed "L-DC" in relation to other myeloid cells, it was necessary to investigate myeloid subsets in more detail. In terms of cell surface phenotype, L-DC were initially characterized as a CD11b(hi)CD11c(lo)MHCII(-)Ly6C(-)Ly6G(-) subset in murine spleen. Their expression of CD43, lack of MHCII, and a low level …
The B Subunit Of Escherichia Coli Heat-Labile Toxin Alters The Development And Antigen-Presenting Capacity Of Dendritic Cells, Jing Ji, Kristin Grifftiths, Peter Milburn, Timothy Hirst, Helen O'Neill
The B Subunit Of Escherichia Coli Heat-Labile Toxin Alters The Development And Antigen-Presenting Capacity Of Dendritic Cells, Jing Ji, Kristin Grifftiths, Peter Milburn, Timothy Hirst, Helen O'Neill
Helen O'Neill
Escherichia coli's heat-labile enterotoxin (Etx) and its non-toxic B subunit (EtxB) have been characterized as adjuvants capable of enhancing T cell responses to co-administered antigen. Here, we investigate the direct effect of intravenously administered EtxB on the size of the dendritic and myeloid cell populations in spleen. EtxB treatment appears to enhance the development and turnover of dendritic and myeloid cells from precursors within the spleen. EtxB treatment also gives a dendritic cell (DC) population with higher viability and lower activation status based on the reduced expression of MHC-II, CD80 and CD86. In this respect, the in vivo effect of …
Characterisation Of The Effect Of Lps On Dc Subset Discrimination In Spleen., Kristin Griffiths, Jonathan Tan, Helen O'Neill
Characterisation Of The Effect Of Lps On Dc Subset Discrimination In Spleen., Kristin Griffiths, Jonathan Tan, Helen O'Neill
Helen O'Neill
The Gram-negative bacterial endotoxin lipopolysaccharide (LPS) is a potent inflammatory mediator and a leading cause of bacterial sepsis. While LPS is known to activate antigen-presenting cells, here we find that LPS down-regulates expression of CD11c and CD11b on splenic dendritic cell subsets, thus confounding the ability to identify these subsets following treatment. This has implications with regard to tracking the response to LPS in terms of the cell subsets involved, and should be considered whenever such studies are undertaken.
Development Of Two Distinct Dendritic-Like Apcs In The Context Of Splenic Stroma, Pravin Periasamy, Sawang Petvises, Helen O'Neill
Development Of Two Distinct Dendritic-Like Apcs In The Context Of Splenic Stroma, Pravin Periasamy, Sawang Petvises, Helen O'Neill
Helen O'Neill
Murine splenic stroma has been found to provide an in vitro niche for hematopoiesis of dendritic-like APC. Two distinct cell types have been characterized. The novel "L-DC" subset has cross-presenting capacity, leading to activation of CD8+ T cells, but not activating CD4+ T cells, which is consistent with their CD11cloCD11bhiMHC-II- phenotype. For L-DC, an equivalent tissue-specific APC has been found only in spleen. A second population of CD11chiCD11bloMHC-II+ cells resembling conventional dendritic cells (cDC) can activate both CD4 and CD8 T cells. Production of L-DC but not cDC-like cells is now shown to be dependent on contact between the L-DC …
Investigation Into The Prevalence Of A Novel Dendritic-Like Cell Subset In Vivo, Kristin Griffiths, Jonathan Tan, Helen O'Neill
Investigation Into The Prevalence Of A Novel Dendritic-Like Cell Subset In Vivo, Kristin Griffiths, Jonathan Tan, Helen O'Neill
Helen O'Neill
A novel dendritic-like cell subset termed L-DC was recently identified in murine spleen based on marker expression of a homogeneous cell population derived from long-term culture of neonatal spleen. The function of L-DC is distinct from other splenic dendritic and myeloid cell subsets because of their high endocytic capacity and their ability to cross-present antigen to CD8+ T cells. This paper shows the subset to be unique to spleen and blood, with a similar, but possibly functionally distinct subset also present in bone marrow. The prevalence of the subset is low; ~6% of all dendritic and myeloid cells in the …
Myelopoiesis In Spleen Producing Distinct Dendritic-Like Cells, Jonathan Tan, Helen O'Neill
Myelopoiesis In Spleen Producing Distinct Dendritic-Like Cells, Jonathan Tan, Helen O'Neill
Helen O'Neill
Dendritic cells (DC) represent a heterogeneous class of antigen presenting cells (APC). Previously we reported a distinct myeloid dendritic-like cell present in spleen, as an in vivo counterpart to cells produced in murine spleen long-term cultures (LTC-DC). These cells, named 'L-DC', were found to be functionally and phenotypically distinct from conventional (c)DC, plasmacytoid (p)DC and monocytes. These results suggested that spleen may represent a niche for development of L-DC from endogenous progenitors. Adult murine spleen has now been investigated for the presence of L-DC progenitors. Lineage-negative (Lin)-ckitlo and Lin-ckithi progenitor subsets were identified as candidate populations, and tested for ability …
Identification Of A Novel Antigen Cross-Presenting Cell In Spleen: A Counterpart To Cells Produced In Long-Term Culture, Jonathan Tan, Ben Quah, Kristin Griffiths, Pravin Periasamy, Yingying Hey, Helen O'Neill
Identification Of A Novel Antigen Cross-Presenting Cell In Spleen: A Counterpart To Cells Produced In Long-Term Culture, Jonathan Tan, Ben Quah, Kristin Griffiths, Pravin Periasamy, Yingying Hey, Helen O'Neill
Helen O'Neill
Antigen-presenting cells (APC), like dendritic cells (DC), are essential for T-cell activation, leading to immunity or tolerance. Multiple DC subsets each play a unique role in the immune response. Here, a novel splenic dendritic-like APC has been characterized in mice that has immune function and cell surface phenotype distinct from other, described DC subsets. These were identified as a cell type continuously produced in spleen long-term cultures (LTC) and have anin vivoequivalent cell type in mice, namely 'L-DC'. This study characterizes LTC-DC in terms of marker phenotype and function, and compares them with L-DC and other known splenic DC and …