Heterogeneity Among CD36+ Cells in Normal and Diseased Human Skin
Brian J. Nickoloff in Dermal Immune System, 2019
Dermal macrophages have been subdivided into various categories (e.g., phagocytic macrophages, dermal dendrocytes, perivascular dendritic cells), depending on their surface determinants, anatomical location, and morphological features. Essentially all of these macrophages are HLA-DR+ cells which are thought to belong to the so-called phagocytic compartment of the monocyte/macrophage system;4,12–15 many are moderately to highly dendritic in shape, hence the name “dendrocyte”. Importantly, these should not be confused with the system of HLA-DR + DCs and LCs which are thought to belong to the immune accessory compartment of the monocyte/macrophage system6,16 and are only abundant in the dermis in certain inflammatory states (Table 1). While published reports do indicate a substantial amount of phenotypic heterogeneity among macrophages in the dermis and other anatomical sites,26 it remains unclear whether the observed differences are indicative of promonocyte cells27 which have become irreversibly committed to a certain subtype with a distinctive function (e.g., melanophage vs. perivascular dendritic cell), or whether there is a single population of macrophages which are susceptible to phenotypic modulation depending on their local microenviroment (e.g., release of neuropeptides,28–30 nerve growth factor,31 and inflammatory cytokines32,33).
Monocyte and lymphocyte membrane markers: Ontogeny and clinical significance
Gabriel Virella in Medical Immunology, 2019
HSCs give rise to the common myeloid progenitors (CMPs), which in turn give rise to the monocyte/dendritic cell progenitors (MDPs) or the granulocyte/monocyte progenitors (GMPs). Maturation then occurs in three stages: monoblast, promonocyte, and monocyte. Monoblasts expressing CD64, CD33, HLA-DR, CD34, and CD4 are derived from both MDP and GMP. As differentiation progresses transition toward promonocytes, there is a loss of CD34 expression and increased expression of CD4 (Figure 10.2). Changes in the expression levels of CD34, HLA-DR, CD117/c-kit, CD64, CD45, CD36, CD14, and CD300 are used to delineate monocyte maturation stages (Table 10.1). Monocytic-myeloid-derived suppressor cells (M-MDSCs) are also differentiated from MDPs.
Macrophages As Effectors Of Cell-Mediated Immunity
Hans H. Gadebusch in Phagocytes and Cellular Immunity, 2020
The origin, structure, and general activities of macrophages have been widely reviewed23,31,35 and will be treated here only in outline. Ther term “mononuclear phagocytic system” (MPS) has been proposed36 to embrace the cells generally referred to as macrophages or members of the reticuloendothelial system and their precursors. Mature macrophages include those found in connective tissue as histiocytes; the liver as Kupffer cells; the pulmonary alveoli, the spleen lymph nodes, and bone marrow as free and fixed macrophages and sinusoidal lining cells; serous cavities as peritoneal macrophages; bone tissues as osteoclasts; and the nervous system, probably as microglia. These cells are derived ultimately from a rapidly dividing precursor (promonocyte) in bone marrow by way of monocytes in blood.37"39 It has been suggested that macrophages may, in some circumstances, arise from precursors with the morphology of lymphocytes.40,41 This suggestion was made, in part, on the basis of experiments with thoracic duct “lymphocytes,” but it is now clear that thoracic duct lymph contains macrophages.42 Lymphocyte to macrophage transformation, if it occurs at all, probably makes only a minor contribution to the body’s supply of macrophages. Mature macrophages are capable of division (see Reference 23 and discussion below) and this may be important in increasing the number of macrophages available as effectors. An increased demand is, however, more likely to be met by increases in the number and activity of monocyte precursors, mainly in the bone marrow.38 Humoral factors — such as colony stimulating factor (CSF) and inhibitors thereof — are probably important in the regulation of monocytopoiesis, though their precise roles are not known.43-45
Importance of distinguishing the promonocyte in leukemia
Published in Baylor University Medical Center Proceedings, 2020
John R. Krause, Arthur Bredeweg
The acute monocytic leukemias are composed of a monoblastic variant and a monocytic variant.1,2 They are morphologically distinguished by the relative proportions of monoblasts and promonocytes. In acute monoblastic leukemia, ≥80% of the cells are monoblasts, whereas in acute monocytic leukemia, most cells are promonocytes or monocytes. Both types require ≥20% blasts. The promonocyte is considered a “blast equivalent.” Monoblasts have round nuclei with delicate lacy chromatin and one or more prominent nucleoli (Figure 1a).3 Promonocytes have irregular and convoluted fine lacy nucleoli with basophilic finely granulated cytoplasm and varying numbers of granules and/or vacuoles (Figure 1b).3 We report a case of acute monocytic leukemia in which the promonocytes morphologically masqueraded as promyelocytes.
Systemic mastocytosis with myeloid sarcoma and B-CLL: molecular and clonal heterogeneity in a rare case of SM-AHN with review of literature
Published in Acta Clinica Belgica, 2023
Philippe Decruyenaere, Dominiek Mazure, Ine Moors, Jo Van Dorpe, Malaïka Van der Linden, Barbara Denys, Mattias Hofmans, Fritz Offner
Subsequently, BM aspiration and trephine biopsy were performed, showing hypercellularity with moderate dysplasia in the erythroid lineage, fibrosis grade 2, as well as the presence of multifocal, dense spindle cell shaped MC infiltrates without blast excess. Immunophenotyping revealed a large MC population with abnormal phenotype (CD2+/CD9+/CD25+/CD33+/CD117+), as well as a small clonal lymphocytic population (0,001%) with a known, aberrant phenotype (CD5+/CD20+/CD45+/CD79b-/CD200+/IgM+), representing residual B-CLL cells. Fine needle aspiration biopsy of the liver showed extramedullary hematopoiesis, MC infiltration with aberrant morphology, as well as a blastoid population, morphologically and immunohistochemically compatible with an AML with promonocyte-monoblastic differentiation (CD2-/CD31+/CD34+/CD43+/CD68+/CD163+/TdT-/MPO-). Diagnostic splenectomy revealed both the MC infiltration, and the blastoid population as observed in the liver (Figure 3). No residual B-CLL cells were present in spleen or liver tissue using a sensitive flow cytometry assay. Serum tryptase level was highly elevated (525 µg/l).
Use of Creatine and Creatinine to Minimize Doxorubicin-Induced Cytotoxicity in Cardiac and Skeletal Muscle Myoblasts
Published in Nutrition and Cancer, 2021
Eric Christopher Bredahl, Wisam Najdawi, Caroline Pass, Jake Siedlik, Joan Eckerson, Kristen Drescher
In addition to its well-documented ergogenic properties (2, 16), Cr supplementation has been shown to be a beneficial adjunct therapy in cardiovascular, muscular, and neurological diseases, as well as diseases characterized by altered energy states (17, 18, 20). Evidence from a number of investigations have also shown that Cr acts as an antioxidant and minimizes oxidative stress in a variety of cell types including cultured cardiac myocytes (7), C2C12 murine-myoblasts (21), human umbilical vein endothelial cells (HUVEC), and U937 human promonocyte cells (21). The cytoprotective effects of Cr have generally been attributed to its ability to supplement short-term ATP production and scavenge ROS, as well as minimize the generation of free radicals caused by Fenton generating reactions (22), which is a primary mechanism underlying DOX-induced oxidative stress (23).
Related Knowledge Centers
- Hematopoietic Stem Cell
- Monocyte
- Monoblast