scholarly journals Neutrophils as regulators of the hematopoietic niche

Blood ◽  
2019 ◽  
Vol 133 (20) ◽  
pp. 2140-2148 ◽  
Author(s):  
Itziar Cossío ◽  
Daniel Lucas ◽  
Andrés Hidalgo
Keyword(s):  
Immune Cells ◽  
Innate Immune System ◽  
Dynamic Structure ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Hematopoietic Stem ◽  
Proliferation And Differentiation ◽  
Stem And Progenitor Cells ◽  
Physiological Demands ◽  
Hematopoietic Niche

Abstract The niche that supports hematopoietic stem and progenitor cells (HSPCs) in the bone marrow is a highly dynamic structure. It maintains core properties of HSPCs in the steady state, and modulates their proliferation and differentiation in response to changing physiological demands or pathological insults. The dynamic and environment-sensing properties of the niche are shared by the innate immune system. Thus, it is not surprising that innate immune cells, including macrophages and neutrophils, are now recognized as important regulators of the hematopoietic niche and, ultimately, of the stem cells from which they derive. This review synthesizes emerging concepts on niche regulation by immune cells, with a particular emphasis on neutrophils. We argue that the unique developmental, circadian, and migratory properties of neutrophils underlie their critical contributions as regulators of the hematopoietic niche.

scholarly journals Hematopoietic stem and progenitor cells are present in healthy gingiva tissue

2021 ◽  
Vol 218 (4) ◽  
Author(s):  
Siddharth Krishnan ◽  
Kelly Wemyss ◽  
Ian E. Prise ◽  
Flora A. McClure ◽  
Conor O’Boyle ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune Responses ◽  
Progenitor Cells ◽  
Myeloid Cell ◽  
Extramedullary Hematopoiesis ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Hematopoietic Stem ◽  
Effector Cells ◽  
Stem And Progenitor Cells

Hematopoietic stem cells reside in the bone marrow, where they generate the effector cells that drive immune responses. However, in response to inflammation, some hematopoietic stem and progenitor cells (HSPCs) are recruited to tissue sites and undergo extramedullary hematopoiesis. Contrasting with this paradigm, here we show residence and differentiation of HSPCs in healthy gingiva, a key oral barrier in the absence of overt inflammation. We initially defined a population of gingiva monocytes that could be locally maintained; we subsequently identified not only monocyte progenitors but also diverse HSPCs within the gingiva that could give rise to multiple myeloid lineages. Gingiva HSPCs possessed similar differentiation potentials, reconstitution capabilities, and heterogeneity to bone marrow HSPCs. However, gingival HSPCs responded differently to inflammatory insults, responding to oral but not systemic inflammation. Combined, we highlight a novel pathway of myeloid cell development at a healthy barrier, defining a gingiva-specific HSPC network that supports generation of a proportion of the innate immune cells that police this barrier.

scholarly journals The IκB-Protein BCL-3 Controls MAPK Activity by Promoting TPL-2 Degradation in the Nucleus

2018 ◽  
Author(s):  
Patricia E. Collins ◽  
Domenico Somma ◽  
David Kerrigan ◽  
Felicity Herrington ◽  
Karen R. Keeshan ◽  
...  
Keyword(s):  
Immune Cells ◽  
Innate Immune System ◽  
Molecular Mechanisms ◽  
Primary Site ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Nucleocytoplasmic Shuttling ◽  
Activation Threshold ◽  
Invasive Pathogens ◽  
Mapk Activity

AbstractThe ability of the innate immune system to distinguish between low level microbial presence and invasive pathogens is fundamental for immune homeostasis and immunity. However, the molecular mechanisms underlying threat discrimination by innate immune cells are not clearly defined. Here we describe the integration of the NF-ĸB and MAPK pathways in the nucleus by the IĸB protein BCL-3 and the MAP3K TPL-2. Our data reveals that TPL-2 is a nucleocytoplasmic shuttling protein and demonstrates that the nucleus is the primary site for TPL-2 ubiquitination and proteasomal degradation. BCL-3 promotes TPL-2 degradation through interaction in the nucleus. As a consequence, Bcl3-/- macrophages have increased TPL-2 stability and MAPK activity following TLR stimulation. The enhanced stability of TPL-2 in Bcl3-/- macrophages lowers the MAPK activation threshold and the level of TLR ligand required to initiate an inflammatory response. This study establishes the nucleus as a key regulatory site for TLR-induced MAPK activity and identifies BCL-3 as a regulator of the cellular decision to initiate inflammation

scholarly journals A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

2021 ◽  
Vol 22 (17) ◽  
pp. 9535
Author(s):  
Yuhuai Xie ◽  
Yuanyuan Wei
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Innate Immune System ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Immune Mediated ◽  
Development And Differentiation ◽  
Non Coding Rnas ◽  
And Function

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

scholarly journals Immune cells—A curse and a blessing!

2021 ◽  
Vol 218 (6) ◽  
Author(s):  
Valbona Mirakaj
Keyword(s):  
Cardiovascular Disease ◽  
Immune System ◽  
Immune Cells ◽  
Innate Immune System ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
The Impact

Innate immune cells are crucial in the development and regulation of cardiovascular disease. In this issue, two groups, Davis et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20201839) and Li et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20210008) describe the impact of the innate immune system on the development of cardiovascular disease.

scholarly journals Understanding the Role of Innate Immune Cells and Identifying Genes in Breast Cancer Microenvironment

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2226
Author(s):  
Israa Shihab ◽  
Bariaa A. Khalil ◽  
Noha Mousaad Elemam ◽  
Ibrahim Y. Hachim ◽  
Mahmood Yaseen Hachim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Immune System ◽  
Tumor Microenvironment ◽  
Nk Cells ◽  
Immune Cells ◽  
Innate Immune System ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Cancer Microenvironment

The innate immune system is the first line of defense against invading pathogens and has a major role in clearing transformed cells, besides its essential role in activating the adaptive immune system. Macrophages, dendritic cells, NK cells, and granulocytes are part of the innate immune system that accumulate in the tumor microenvironment such as breast cancer. These cells induce inflammation in situ by secreting cytokines and chemokines that promote tumor growth and progression, in addition to orchestrating the activities of other immune cells. In breast cancer microenvironment, innate immune cells are skewed towards immunosuppression that may lead to tumor evasion. However, the mechanisms by which immune cells could interact with breast cancer cells are complex and not fully understood. Therefore, the importance of the mammary tumor microenvironment in the development, growth, and progression of cancer is widely recognized. With the advances of using bioinformatics and analyzing data from gene banks, several genes involved in NK cells of breast cancer individuals have been identified. In this review, we discuss the activities of certain genes involved in the cross-talk among NK cells and breast cancer. Consequently, altering tumor immune microenvironment can make breast tumors more responsive to immunotherapy.

scholarly journals Stress Hyperglycemia, Insulin Treatment, and Innate Immune Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fangming Xiu ◽  
Mile Stanojcic ◽  
Li Diao ◽  
Marc G. Jeschke
Keyword(s):  
Insulin Resistance ◽  
Innate Immunity ◽  
Immune System ◽  
Critical Illness ◽  
Immune Cells ◽  
Innate Immune System ◽  
Insulin Treatment ◽  
Innate Immune ◽  
Morbidity And Mortality ◽  
Innate Immune Cells

Hyperglycemia (HG) and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

scholarly journals The Role of Macrophages in Staphylococcus aureus Infection

2021 ◽  
Vol 11 ◽  
Author(s):  
Grace R. Pidwill ◽  
Josie F. Gibson ◽  
Joby Cole ◽  
Stephen A. Renshaw ◽  
Simon J. Foster
Keyword(s):  
Staphylococcus Aureus ◽  
Immune System ◽  
Immune Cells ◽  
Innate Immune System ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Multiple Strategies ◽  
Aureus Infection ◽  
Opportunist Pathogen

Staphylococcus aureus is a member of the human commensal microflora that exists, apparently benignly, at multiple sites on the host. However, as an opportunist pathogen it can also cause a range of serious diseases. This requires an ability to circumvent the innate immune system to establish an infection. Professional phagocytes, primarily macrophages and neutrophils, are key innate immune cells which interact with S. aureus, acting as gatekeepers to contain and resolve infection. Recent studies have highlighted the important roles of macrophages during S. aureus infections, using a wide array of killing mechanisms. In defense, S. aureus has evolved multiple strategies to survive within, manipulate and escape from macrophages, allowing them to not only subvert but also exploit this key element of our immune system. Macrophage-S. aureus interactions are multifaceted and have direct roles in infection outcome. In depth understanding of these host-pathogen interactions may be useful for future therapeutic developments. This review examines macrophage interactions with S. aureus throughout all stages of infection, with special emphasis on mechanisms that determine infection outcome.

scholarly journals Innate immune cells as homeostatic regulators of the hematopoietic niche

2014 ◽  
Vol 99 (6) ◽  
pp. 685-694 ◽  
Author(s):  
María Casanova-Acebes ◽  
Noelia A-González ◽  
Linnea A. Weiss ◽  
Andrés Hidalgo
Keyword(s):  
Immune Cells ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Hematopoietic Niche

scholarly journals Evolutionary Protection of Krüppel-Like Factors 2 and 4 in the Development of the Mature Hemovascular System

2021 ◽  
Vol 8 ◽  
Author(s):  
David R. Sweet ◽  
Cherry Lam ◽  
Mukesh K. Jain
Keyword(s):  
Endothelial Cells ◽  
Immune Cells ◽  
Inflammatory Diseases ◽  
Evolutionary Relationship ◽  
Nucleotide Composition ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Cellular Quiescence ◽  
Physiological Demands ◽  
Cellular Compartments

A properly functioning hemovascular system, consisting of circulating innate immune cells and endothelial cells (ECs), is essential in the distribution of nutrients to distant tissues while ensuring protection from invading pathogens. Professional phagocytes (e.g., macrophages) and ECs have co-evolved in vertebrates to adapt to increased physiological demands. Intercellular interactions between components of the hemovascular system facilitate numerous functions in physiology and disease in part through the utilization of shared signaling pathways and factors. Krüppel-like factors (KLFs) 2 and 4 are two such transcription factors with critical roles in both cellular compartments. Decreased expression of either factor in myeloid or endothelial cells increases susceptibility to a multitude of inflammatory diseases, underscoring the essential role for their expression in maintaining cellular quiescence. Given the close evolutionary relationship between macrophages and ECs, along with their shared utilization of KLF2 and 4, we hypothesize that KLF genes evolved in such a way that protected their expression in myeloid and endothelial cells. Within this Perspective, we review the roles of KLF2 and 4 in the hemovascular system and explore evolutionary trends in their nucleotide composition that suggest a coordinated protection that corresponds with the development of mature myeloid and endothelial systems.

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