Blocked lectins, methods and affinity support for making same using affinity ligands, and method of killing selected cell populations having reduced nonselective cytotoxicity

摘要

An activated affinity ligand is described comprising: a ligand having (a) a region with affinity for binding sites of a lectin; and (b) a reactive group capable of covalently linking the ligand to the lectin to thereby block one or more of the binding sites of the lectin. A blocked lectin is described comprising one or more affinity ligands covalently linked by means of a reactive group present on each of the ligands to a lectin such that one or more binding sites of the lectin is blocked. A cell-binding agent-blocked lectin conjugate is described comprising the above-described blocked lectin and a cell-binding agent covalently linked to: (a) one of the covalently linked affinity ligands; or (b) the lectin. A method of preparing a blocked lectin is described. A method of preparing the cell-binding agent-blocked lectin conjugate is described. An affinity support capable of binding to a lectin to form a blocked lectin is described comprising an activated affinity ligand covalently linked to a solid support. A method of preparing the affinity support capable of binding to a lectin to form a blocked lectin is described. A method of killing selected cell populations having reduced cytotoxicity to non-selected cell populations is described comprising contacting a cell population or tissue suspected of containing cells from said selected cell population with the above-described cell-binding agent- blocked lectin conjugate, wherein the lectin is a cytotoxic lectin. Medicaments and methods of treatment using the above-described cell- binding agent-blocked lectin conjugate also are described.