monocyte homeostasis

Definition

Target type: biologicalprocess

The process of regulating the proliferation and elimination of monocytes such that the total number of monocytes within a whole or part of an organism is stable over time in the absence of an outside stimulus. [CL:0000576, GOC:BHF, PMID:18832716]

Monocyte homeostasis is a tightly regulated process that ensures a constant supply of monocytes, a type of white blood cell crucial for innate immunity and tissue repair. This process involves a complex interplay between multiple factors including bone marrow production, circulation in the blood, differentiation into macrophages and dendritic cells in tissues, and removal of senescent or damaged monocytes.

Monocyte production occurs in the bone marrow, where hematopoietic stem cells differentiate into committed myeloid progenitors. These progenitors undergo several stages of maturation, ultimately giving rise to monocytes. The production of monocytes is influenced by various factors like colony-stimulating factors (CSFs) such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF), which promote the survival and differentiation of monocytic progenitors.

Newly formed monocytes enter the bloodstream and circulate for a limited time, typically a few days. They then migrate to various tissues, where they differentiate into macrophages and dendritic cells. Macrophages play a critical role in phagocytosing pathogens, cellular debris, and apoptotic cells, contributing to tissue repair and immune response. Dendritic cells act as antigen-presenting cells, initiating adaptive immune responses by presenting antigens to T cells.

The removal of senescent or damaged monocytes from circulation is crucial for maintaining monocyte homeostasis. This process is primarily mediated by apoptosis, a programmed cell death mechanism. Apoptotic monocytes are recognized and engulfed by macrophages, preventing their accumulation in the blood and contributing to tissue homeostasis.

Monocyte homeostasis is a dynamic process that is constantly adapting to changes in the body's needs. For instance, during infections or injuries, the production of monocytes increases to meet the demand for immune cells. Conversely, under normal conditions, the production and removal of monocytes are tightly balanced to maintain a steady supply of these essential cells.'
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Proteins (1)

Compounds (4)