myeloidderived

Myeloid-derived is a descriptor used in biology and medicine to indicate cells, cells' precursors, or factors that originate from the myeloid lineage. In the immune system, this distinction is made to separate myeloid-origin components from those arising from the lymphoid lineage, such as B and T lymphocytes and NK cells. The myeloid lineage includes monocytes, macrophages, neutrophils, eosinophils, basophils, mast cells, dendritic cells, and related cell types that arise from hematopoietic stem cells through myeloid progenitors. The term can refer to mature cells as well as immature progenitors and to products they produce, such as enzymes, cytokines, or reactive species.

A prominent example is myeloid-derived suppressor cells (MDSCs), a heterogeneous group of immature myeloid cells that accumulate in cancer, chronic infection, and inflammatory conditions. MDSCs suppress T cell and natural killer cell activity through mechanisms including depletion of L-arginine by arginase-1, production of nitric oxide and reactive oxygen species, and induction of regulatory T cells. In humans, MDSCs are typically divided into monocytic and granulocytic (or PMN) subsets, with function influenced by the inflammatory environment. MDSCs are a focus of research due to their role in immune evasion by tumors and potential as therapeutic targets.

Myeloid-derived dendritic cells (moDCs) form when monocytes differentiate into antigen-presenting cells capable of activating T cells and shaping adaptive immunity. They are studied for vaccines and immunotherapy, and their function is regulated by cytokines, pathogen-associated signals, and tissue context.

In broader terms, other myeloid-derived cells such as macrophages and neutrophils participate in defense, tissue repair, and inflammation. The label “myeloid-derived” emphasizes origin from the myeloid lineage and is used across contexts where distinguishing lineage is relevant.