Both Tc1 and Tc2 populations demonstrate allospecific cytolytic function. CD8⁺ T cells and bone marrow were collected from each of 2 normal donors (A and B). Bone marrow–derived allostimulatory cells were generated by culturing low-density bone marrow cells for 10 days in IL-4, GM-CSF, IL-7, and NAC. Allospecific CD8⁺ T cells of Tc1 or Tc2 phenotype were generated by in vitro coculture of CD8⁺ cells with bone marrow–derived allogeneic stimulator cells in the presence of either IL-12 (2.5 ng/mL) and TGF-β (5 ng/mL) or IL-4 (1,000 U/mL), respectively. On day 13 of culture, allospecific Tc1 and Tc2 populations were harvested and plated in a 4-hour ⁵¹Cr-release assay at the E:T ratios indicated with either allogeneic or autologous bone marrow–derived cells as targets. A anti-B, culture of CD8⁺ T cells from donor A with stimulator cells from donor B; B anti-A, culture of CD8⁺ T cells from donor B with stimulator cells from donor A.