Immune system cells

Immune system cells, collectively referred to as leukocytes, are the primary cellular components of the vertebrate immune system responsible for defending the body against infectious agents and foreign substances [NIH, 2023]. This broad category encompasses diverse cell types including lymphocytes (T cells, B cells, and natural killer cells), myeloid cells (neutrophils, monocytes, macrophages), and dendritic cells, each playing specialized roles in innate and adaptive immunity [StatPearls, 2023]. Because this term refers to an entire cellular population rather than a specific protein or molecule, it is considered too non-specific to serve as a defined therapeutic target in modern pharmacology [PubMed, 2021]. Instead, drug development focuses on specific molecular targets within these cells, such as kinases, receptors, or cytokines, to modulate immune function. Pathological states involving these cells include autoimmune diseases, where the immune system attacks host tissues, and various cancers, where immune evasion or over-proliferation occurs [NCBI, 2022]. Broad-acting drugs like corticosteroids or cytotoxic agents interact with these cells by inhibiting proliferation or inducing apoptosis to manage systemic inflammation [PubChem, 2023].

Other names

LeukocytesWhite blood cellsImmune effectorsHematopoietic immune cells

Drugs targeting these cells generally act by inhibiting cellular proliferation, modulating cytokine production, or inducing cell death to suppress overactive immune responses.