Physiological hematopoietic and immune cell populations (HSPCs/Leukocytes)

Physiological hematopoietic and immune cell populations refer to the collective group of specialized cells derived from hematopoietic stem cells (HSCs) in the bone marrow, including erythrocytes, megakaryocytes, and various myeloid and lymphoid leukocytes [1]. These populations are fundamental to human physiology, providing the basis for oxygen delivery, hemostasis, and the innate and adaptive immune responses [2]. While not a single molecular target, these cell populations are critical in pharmacology as they are often the unintended targets of cytotoxic chemotherapy, leading to dose-limiting toxicities such as myelosuppression [3]. Conversely, they are the primary focus of regenerative and supportive therapies, such as colony-stimulating factors (e.g., G-CSF) used to recover white blood cell counts or immunosuppressive agents used to modulate overactive immune responses in autoimmune diseases [4]. Monitoring the health and composition of these populations through biomarkers like CD34 and absolute cell counts is a standard practice in clinical oncology and hematology to ensure patient safety during treatment [5]. (Sources: [1] https://www.ncbi.nlm.nih.gov/books/NBK534811/; [2] https://www.niaid.nih.gov/research/immune-system-disorders; [3] https://www.cancer.gov/publications/dictionaries/cancer-terms/def/myelosuppression; [4] https://pubmed.ncbi.nlm.nih.gov/24507156/; [5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3661114/)

Other names

Hematopoietic systemImmune systemBlood cell populationsHematopoietic stem and progenitor cellsLeukocytesMyeloid and lymphoid lineages

Drugs interacting with these populations typically act via myelosuppression (cytotoxic depletion), immunostimulation (growth factor signaling), or immunosuppression (inhibition of proliferation/activation).