Conjugates targeted to the interleukin-2 receptor

Abstract

A composition for intracellular delivery of a chemical agent into an interleukin-2-receptor-bearing cell, e.g. an activated T cell, includes a chemical agent and at least one copy of an interleukin-2-receptor-binding and endocytosis-inducing ligand coupled to a water soluble polymer. The ligand binds to a receptor on the interleukin-2-receptor-bearing cell and elicits endocytosis of the composition. The composition also preferably includes a spacer for coupling the chemical agent and the ligand to the polymer. Chemical agents can include cytotoxins, transforming nucleic acids, gene regulators, labels, antigens, drugs, and the like. A preferred water soluble polymer is a polyalkylene oxide, such as polyethlene glycol and polyethylene oxide, and activated derivatives thereof. The composition can further comprise a carrier such as another water soluble polymer, liposome, or particulate. Methods of using these compositions for delivering a chemical agent in vivo or in vitro are also disclosed. A method of detecting a disease, such as T-cell lymphocytic leukemia, T-cell acute lymphoblastic leukemia, peripheral T-cell lymphoma, Hodgkin's disease, or non-Hodgkin's lymphoma, associated with elevated levels of soluble IL-2 receptor is also disclosed.