Kohdesolun

Kohdesolun is a Finnish term that translates as "target cell" and is used in biological and medical contexts to denote a cell that is the intended recipient of an interaction, effect or intervention. The concept applies across disciplines including endocrinology, immunology, pharmacology and virology.

In physiology, a target cell carries receptors that bind specific hormones or signaling molecules; the presence, density and downstream signaling machinery of those receptors determine the cell's responsiveness. In immunology, a target cell is one recognized by immune effectors—such as cytotoxic T lymphocytes or natural killer cells—because it displays particular antigens or stress signals. In virology and microbial pathogenesis, target cells are those permissive to entry and replication by a pathogen, often determined by surface receptors and intracellular factors. In pharmacology and toxicology, drugs and toxins act on target cells where intended therapeutic or adverse effects occur.

Determinants of target-cell specificity include receptor expression, tissue accessibility, local microenvironment, and intracellular pathways that permit or restrict a response. Clinically, identifying and manipulating target cells underpins targeted therapies, vaccine design, and cell-specific drug delivery strategies aimed at increasing efficacy and reducing off-target effects. Laboratory methods used to study target cells include receptor binding assays, flow cytometry, cell culture infection models, and imaging of ligand–receptor interactions.