Patent ID: 8637307

Claim:
An isolated population of T cells expanded and restimulated by a method comprising: contacting a population of T cells with an engineered K562 cell, said engineered K562 cell comprising on its surface: 1) an exogenous antibody that binds to CD3 or CD2, 2) a molecule that binds CD28, wherein the molecule that binds CD28 is selected from the group consisting of anti-CD28 antibody, CD80, and CD86, and 3) the natural 4-1BBL; and expanding said population of T cells by culturing said population of T cells under conditions and time sufficient to induce cell division, wherein said contacting and/or said culturing occurs in the absence of exogenously added cytokines, wherein said T cells so expanded are substantially free of said engineered K562 cell, followed by restimulating said T cells wherein said T cells remain in exponential growth after restimulation.