A method of enhancing binding of cells to an integrin-binding ligand comprises treating integrin-expressing cells in vitro with an agonist of integrin, wherein the integrin is selected from the group consisting of α4β1, α5β1, α4β7, αvβ3 and αLβ2, and contacting the treated cells with an integrin-binding ligand; integrin agonist compounds having the general formula I; methods of treating integrin-expressing cells with such agonists to enhance binding; and therapeutic methods comprising administering agonist-treated cells or agonist compounds to a mammal.