A population of T cells that have been sensitized to vaccine tumor antigen(s) in vivo; collected from the patient; co-stimulated with antibodies to the T-cell cell surface proteins CD3 and CD28 and expanded ex vivo; and then infused into the same patient. CD3, part of the T cell receptor complex, and CD28, a T-cell surface-associated co-stimulatory molecule, are both required for full T-cell activation. Adoptive transfer of CD3/CD28 costimulated vaccine-primed autologous T-cells may induce the production of interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF) and associated antitumor effects and a graft-versus-tumor (GVT) response. Check for active clinical trialsusing this agent.