Figure S2. IL-2 alone and anti-IL-2 antibody (S4B6) alone do not cause expansion of the donor NK cell pool (PDF, 18 KB) - Irradiated bone marrow recipients were left untreated, treated with IL-2 alone (1.5 mg), S4B6 alone (50 mg) or IL-2 complex on day 2 and 4 after bone marrow transfer. Neither IL-2 alone nor S4B6 alone increased the percentage of NK1.1+CD3- cells in the spleen (not shown). IL-2 complex treatment caused massive donor derived NK cell expansion, which was not observed in the two control groups.