Using CD3/CD28 immunomagnetic beads for magnetic cell separation, CD3+ T cells can be isolated and enriched from the obtained separation product. After isolation, CD3+ T cells were cultured in the presence of magnetic beads. By binding anti-CD3 and anti-CD28 antibodies on immunomagnetic beads, magnetic beads can provide the primary and costimulatory signals required for T cell activation and expansion. Activated T cells produce IL-2 (interleukin 2), GM-CSF (granulocyte macrophage stimulating factor), IFN-γ (interferon), and (tumor necrosis factor alpha), which play the role and function of T cells.