-
Journal of Leukocyte Biology Aug 2019Monocytes are innate immune cells of the mononuclear phagocyte system that have emerged as important regulators of cancer development and progression. Our understanding... (Review)
Review
Monocytes are innate immune cells of the mononuclear phagocyte system that have emerged as important regulators of cancer development and progression. Our understanding of monocytes has advanced from viewing these cells as a homogenous population to a heterogeneous system of cells that display diverse responses to different stimuli. During cancer, different monocyte subsets perform functions that contribute to both pro- and antitumoral immunity, including phagocytosis, secretion of tumoricidal mediators, promotion of angiogenesis, remodeling of the extracellular matrix, recruitment of lymphocytes, and differentiation into tumor-associated macrophages and dendritic cells. The ability of cancer to evade immune recognition and clearance requires protumoral signals to outweigh ongoing attempts by the host immune system to prevent tumor growth. This review discusses current understanding of monocyte heterogeneity during homeostasis, highlights monocyte functions in cancer progression, and describes monocyte-targeted therapeutic strategies for cancer treatment.
Topics: Animals; Biomarkers; Cell Movement; Combined Modality Therapy; Disease Management; Disease Susceptibility; Humans; Immunophenotyping; Monocytes; Neoplasms; Tumor Microenvironment
PubMed: 30776148
DOI: 10.1002/JLB.4RI0818-311R -
Cytometry. Part B, Clinical Cytometry May 2017In April 2013, a symposium was organized to highlight different aspects of differentiation and activation of the monocyte-macrophage lineage as analyzed on the flow...
In April 2013, a symposium was organized to highlight different aspects of differentiation and activation of the monocyte-macrophage lineage as analyzed on the flow cytometer. Characterization of this lineage requires knowledge of the maturation process from their progenitors that are present in bone marrow up to the mature monocytic cells in peripheral blood, because each monocytic lineage cell with an aberrant phenotype refers to the corresponding maturation stage. A standardized quantitative analysis will facilitate the monitoring of the pathological processes and the clinical features, such as the outcome of treatment. However, changes in marker expression by variation in intensity, asynchronism, and lineage infidelity must be considered. The dynamics of normal marker expressions in early differentiation stages, e.g. molecules like HLA II, CD64 or CD14, give rise to a hypothesis on their possible role in monocyte ontogeny. Besides their usual role in tissue homeostasis, mature macrophages may also play a similar role in hematopoiesis. This meeting highlighted the large potential of flow cytometric tools available for monitoring of all these aspects in the monocytic and macrophage cell lineage. © 2015 International Clinical Cytometry Society.
Topics: Cell Differentiation; Cell Lineage; Flow Cytometry; Humans; Macrophages; Monocytes
PubMed: 26332381
DOI: 10.1002/cyto.b.21280 -
Cancer Research Mar 2014Growing understanding of the role of the tumor microenvironment in angiogenesis has brought monocyte-derived cells into focus. Monocyte subpopulations are an... (Review)
Review
Growing understanding of the role of the tumor microenvironment in angiogenesis has brought monocyte-derived cells into focus. Monocyte subpopulations are an increasingly attractive therapeutic target in many pathologic states, including cancer. Before monocyte-directed therapies can be fully harnessed for clinical use, understanding of monocyte-driven angiogenesis in tissue development and homeostasis, as well as malignancy, is required. Here, we provide an overview of the mechanisms by which monocytic subpopulations contribute to angiogenesis in tissue and tumor development, highlight gaps in our existing knowledge, and discuss opportunities to exploit these cells for clinical benefit.
Topics: Animals; Humans; Monocytes; Neoplasms; Neovascularization, Pathologic; Tumor Microenvironment
PubMed: 24556724
DOI: 10.1158/0008-5472.CAN-13-2825 -
The American Journal of Pathology May 2020Monocyte rolling, adhesion, and transmigration across the endothelium are mediated by specific interactions between surface adhesion molecules. This process is... (Review)
Review
Monocyte rolling, adhesion, and transmigration across the endothelium are mediated by specific interactions between surface adhesion molecules. This process is fundamental to innate immunity and to inflammatory disease, including atherosclerosis, where monocyte egress into the intimal space is central to formation of fatty plaques. Monocytes are a heterogeneous population of three distinct subsets of cells, all of which play different roles in atherosclerosis progression. However, it is not well understood how interactions between different monocyte subsets and the endothelium are regulated. Furthermore, it is appreciated that endothelial adhesion molecules are heavily N-glycosylated, but beyond regulating protein trafficking to the cell surface, whether and if so how these N-glycans contribute to monocyte recruitment is not known. This review discusses how changes in endothelial N-glycosylation may impact vascular and monocytic inflammation. It will also discuss how regulating N-glycoforms on the endothelial surface may allow for the recruitment of specific monocyte subsets to sites of inflammation, and how further understanding in this area may lead to the development of glyco-specific therapeutics in the treatment of cardiovascular disease.
Topics: Animals; Cell Adhesion Molecules; Endothelial Cells; Glycosylation; Humans; Leukocyte Rolling; Monocytes; Polysaccharides
PubMed: 32084367
DOI: 10.1016/j.ajpath.2020.01.006 -
Revista Espanola de Quimioterapia :... Apr 2022Sepsis is one of the main causes of mortality in the emergency department (ED), due to the fact that signs and symptoms are common to other acute diseases, and this can... (Review)
Review
Sepsis is one of the main causes of mortality in the emergency department (ED), due to the fact that signs and symptoms are common to other acute diseases, and this can result in delayed detection. This diagnostic complexity has a huge impact on an entity in which early recognition determined treatment, as wells as enhance the patient's prognosis. Therefore, it is crucial to improve early identification. Different analytical tools arise from this approach, such as biomarkers: procalcitonin, C-reactive protein or MR-proadrenomedullin. In this review we will focus on a newer biomarker, the monocyte distribution width. The main objectives are to evaluate the usefulness of monocyte distribution width (MDW) in sepsis identification in ED, its limitations, and to compare it with other biomarker.
Topics: Biomarkers; C-Reactive Protein; Humans; Monocytes; Procalcitonin; Sepsis
PubMed: 35488816
DOI: 10.37201/req/s01.01.2022 -
Frontiers in Immunology 2019Blood monocytes develop in the bone marrow before being released into the peripheral circulation. The circulating monocyte pool is composed of multiple subsets, each... (Review)
Review
Blood monocytes develop in the bone marrow before being released into the peripheral circulation. The circulating monocyte pool is composed of multiple subsets, each with specialized functions. These cells are recruited to repopulate resident monocyte-derived cells in the periphery and also to sites of injury. Several extrinsic factors influence the function and quantity of monocytes in the blood. Here, we outline the impact of sex, ethnicity, age, sleep, diet, and exercise on monocyte subsets and their function, highlighting that steady state is not a single physiological condition. A clearer understanding of the relationship between these factors and the immune system may allow for improved therapeutic strategies.
Topics: Aging; Animals; Environment; Ethnicity; Exercise; Homeostasis; Humans; Inheritance Patterns; Leukopoiesis; Life Style; Monocytes; Sex Characteristics; Sleep
PubMed: 31787976
DOI: 10.3389/fimmu.2019.02581 -
Immunobiology Dec 2012Atherosclerosis has been characterized as an inflammatory process, in which monocytes and monocyte-derived macrophages are of paramount importance. Contrasting with... (Review)
Review
Atherosclerosis has been characterized as an inflammatory process, in which monocytes and monocyte-derived macrophages are of paramount importance. Contrasting with their established role in atherosclerosis, monocytes have not unanimously been found to predict cardiovascular events in large epidemiological studies. However, in these studies human monocyte heterogeneity has been largely overlooked so far. Three human monocyte subsets can be distinguished: classical CD14(++)CD16(-), intermediate CD14(++)CD16(+) and nonclassical CD14(+)CD16(++) monocytes. Of note, correct enumeration of subset counts requires appropriate staining and gating strategies that encompass a pan-monocytic marker (e.g. HLA-DR or CD86). In experimental studies on murine atherogenesis a monocyte subset-specific contribution to atherosclerosis has been established. However, major interspecies differences in atherogenesis itself, as well as in the immune system (including monocyte subset phenotype and distribution) preclude a direct extrapolation to human pathology. Experimental and pilot clinical studies point to a prominent involvement of intermediate CD14(++)CD16(+) monocytes in human atherosclerosis. Future clinical studies should analyze monocyte heterogeneity in cardiovascular disease. If a specific contribution of intermediate monocytes should be confirmed, immunomodulation of this monocyte subset could represent a future therapeutic target in atherosclerosis.
Topics: Animals; Cardiovascular Diseases; Humans; Monocytes
PubMed: 22898391
DOI: 10.1016/j.imbio.2012.07.001 -
The Journal of Experimental Medicine Apr 2015
Review
Topics: Animals; Antigens, Differentiation; Humans; Mice; Monocytes; Portraits as Topic
PubMed: 25847970
DOI: 10.1084/jem.2124insight1 -
Cellular Immunology 2014Monocytes are mononuclear myeloid cells that develop in the bone marrow and circulate within the bloodstream. Although they have long been argued to play a role in the... (Review)
Review
Monocytes are mononuclear myeloid cells that develop in the bone marrow and circulate within the bloodstream. Although they have long been argued to play a role in the repopulation of tissue-resident macrophages, this has been questioned by numerous recent studies, which has forced a reappraisal of their biology. Here we discuss monocyte development, as well as the homeostatic control of monocyte subpopulations within the blood. We also outline the known functions of monocyte subsets. Finally, we highlight the plastic nature of monocytes, which are capable of a remarkable range of phenotypic and functional changes that depend on signals from local microenvironments.
Topics: Animals; Cell Lineage; Homeostasis; Humans; Inflammation; Mice; Monocytes
PubMed: 24962351
DOI: 10.1016/j.cellimm.2014.05.010 -
Cellular Immunology 2014Monocyte development is a tightly regulated and multi-staged process, occurring through several defined progenitor cell intermediates. The key transcription factors,... (Review)
Review
Monocyte development is a tightly regulated and multi-staged process, occurring through several defined progenitor cell intermediates. The key transcription factors, including PU.1, IRF8 and KLF4, growth factors, such as M-CSF and IL-34 and cytokines that drive monocyte development from hematopoietic progenitor cells are well defined. However, the molecular controls that direct differentiation into the Ly6C(hi) inflammatory and Ly6C(lo) monocyte subsets are yet to be completely elucidated. This review will provide a summary of the transcriptional regulation of monocyte development. We will also discuss how these molecular controls are also critical for microglial development despite their distinct haematopoetic origins. Furthermore, we will examine recent breakthroughs in defining mechanisms that promote differentiation of specific monocyte subpopulations.
Topics: Animals; Cell Differentiation; Kruppel-Like Factor 4; Mice; Monocytes; Stem Cells; Transcription, Genetic
PubMed: 24709055
DOI: 10.1016/j.cellimm.2014.02.008