scholarly journals TLR2 and Dectin-1 Signaling in Mouse Hematopoietic Stem and Progenitor Cells Impacts the Ability of the Antigen Presenting Cells They Produce to Activate CD4 T Cells

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1317 ◽  
Author(s):  
Alba Martínez ◽  
Cristina Bono ◽  
Daniel Gozalbo ◽  
Helen S. Goodridge ◽  
M. Luisa Gil ◽  
...  

Microbial recognition by pattern recognition receptors (PRRs) expressed on hematopoietic stem and progenitor cells (HSPCs) not only activates myelopoiesis but also programs the function of the monocytes and macrophages they produce. For instance, changes in HSPC programming modify the ability of macrophages derived from them to produce inflammatory cytokines. While HSPCs exposed to a TLR2 agonist give rise to tolerized macrophages (lower proinflammatory cytokine production), HSPCs treated with Dectin-1 ligands produce trained macrophages (higher proinflammatory cytokine production). However, nothing is known about the impact of HSPC exposure to microbes on the function of antigen presenting cells (APCs). In this study we evaluated whether treatment of murine bone marrow HSPCs with a TLR2 or Dectin-1 ligand impacts the antigen presenting capacity of APCs derived from them in vitro. Following activation with microbial ligands or Candida albicans yeasts, APCs derived from TLR2/Dectin-1-programed HSPCs exhibit altered expression of MHCII (signal 1), co-stimulatory molecules (CD40, CD80 and CD86; signal 2) and cytokines (TNF-α, IL-6, IL-12 p40 and IL-2; signal 3). Moreover, APCs derived from TLR2/Dectin-1-programed HSPCs prime enhanced Th1 and Th17 responses, which are important for antifungal defense, in CD4 T cell cocultures. Overall, these results demonstrate for the first time that microbial detection by bone marrow HSPCs can modulate the adaptive immune response by inducing the production of APCs with an altered phenotype.

Blood ◽  
2009 ◽  
Vol 113 (10) ◽  
pp. 2352-2362 ◽  
Author(s):  
Rupali Das ◽  
Xiao Chen ◽  
Richard Komorowski ◽  
Martin J. Hessner ◽  
William R. Drobyski

Abstract Damage to the gastrointestinal tract during graft-versus-host disease (GVHD) from the conditioning regimen in conjunction with alloreactive donor T cells plays a pivotal role in the pathogenesis of this disease. In this study, we have identified secretion of interleukin-23 (IL-23) by donor antigen-presenting cells (APCs) as a critical event in the induction of GVHD of the colon linking conditioning regimen-induced mucosal injury and lipopoly-saccharide (LPS) translocation to subsequent proinflammatory cytokine production and GVHD-associated pathologic damage. In the absence of donor APC-derived IL-23 secretion, there is a selective and profound reduction in pathologic damage as well as a marked reduction in LPS and proinflammatory cytokine production in the colon microenvironment. The downstream proinflammatory effects of IL-23 are dependent upon donor-derived secretion of interferon-γ (IFN-γ), but are independent of donor IL-17 production. These findings define a novel organ-specific role for IL-23 in the pathophysiology of GVHD and demonstrate that IL-23 can direct tissue-specific pathology within the context of a systemic inflammatory disorder. Furthermore, these studies also identify IL-23 as a potential therapeutic target for the prevention of this life-threatening disorder.


Blood ◽  
2010 ◽  
Vol 116 (17) ◽  
pp. 3197-3207 ◽  
Author(s):  
Kirsteen J. Campbell ◽  
Mary L. Bath ◽  
Marian L. Turner ◽  
Cassandra J. Vandenberg ◽  
Philippe Bouillet ◽  
...  

Abstract Diverse human cancers with poor prognosis, including many lymphoid and myeloid malignancies, exhibit high levels of Mcl-1. To explore the impact of Mcl-1 overexpression on the hematopoietic compartment, we have generated vavP-Mcl-1 transgenic mice. Their lymphoid and myeloid cells displayed increased resistance to a variety of cytotoxic agents. Myelopoiesis was relatively normal, but lymphopoiesis was clearly perturbed, with excess mature B and T cells accumulating. Rather than the follicular lymphomas typical of vavP-BCL-2 mice, aging vavP-Mcl-1 mice were primarily susceptible to lymphomas having the phenotype of a stem/progenitor cell (11 of 30 tumors) or pre-B cell (12 of 30 tumors). Mcl-1 overexpression dramatically accelerated Myc-driven lymphomagenesis. Most vavP-Mcl-1/ Eμ-Myc mice died around birth, and transplantation of blood from bitransgenic E18 embryos into unirradiated mice resulted in stem/progenitor cell tumors. Furthermore, lethally irradiated mice transplanted with E13 fetal liver cells from Mcl-1/Myc bitransgenic mice uniformly died of stem/progenitor cell tumors. When treated in vivo with cyclophosphamide, tumors coexpressing Mcl-1 and Myc transgenes were significantly more resistant than conventional Eμ-Myc lymphomas. Collectively, these results demonstrate that Mcl-1 overexpression renders hematopoietic cells refractory to many cytotoxic insults, perturbs lymphopoiesis and promotes malignant transformation of hematopoietic stem and progenitor cells.


Author(s):  
Omika Katoch ◽  
Mrinalini Tiwari ◽  
Namita Kalra ◽  
Paban K. Agrawala

AbstractDiallyl sulphide (DAS), the pungent component of garlic, is known to have several medicinal properties and has recently been shown to have radiomitigative properties. The present study was performed to better understand its mode of action in rendering radiomitigation. Evaluation of the colonogenic ability of hematopoietic progenitor cells (HPCs) on methocult media, proliferation and differentiation of hematopoietic stem cells (HSCs), and transplantation of stem cells were performed. The supporting tissue of HSCs was also evaluated by examining the histology of bone marrow and in vitro colony-forming unit–fibroblast (CFU-F) count. Alterations in the levels of IL-5, IL-6 and COX-2 were studied as a function of radiation or DAS treatment. It was observed that an increase in proliferation and differentiation of hematopoietic stem and progenitor cells occurred by postirradiation DAS administration. It also resulted in increased circulating and bone marrow homing of transplanted stem cells. Enhancement in bone marrow cellularity, CFU-F count, and cytokine IL-5 level were also evident. All those actions of DAS that could possibly add to its radiomitigative potential and can be attributed to its HDAC inhibitory properties, as was observed by the reversal radiation induced increase in histone acetylation.


Stem Cells ◽  
1999 ◽  
Vol 17 (6) ◽  
pp. 339-344 ◽  
Author(s):  
John Eugenes Chisi ◽  
Joanna Wdzieczak‐Bakala ◽  
Josiane Thierry ◽  
Cecile V. Briscoe ◽  
Andrew C. Riches

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