KRN7000 promotes NK- and T-cell activation after SCT. (A) Irradiated B6 or B6D2F₁ mice received whole spleen from G-CSF–mobilized BALB/c or B6 allogeneic donors, respectively, followed by control diluent, C20:2, or KRN7000 IP on days +1 and +4. Hepatic lymphocytes were pooled from 4 to 5 mice per group at days 2 and 5 after transplant, gradient-purified, and IFN-γ secretion by cell subsets determined by cytokine secretion assay. Representative plots from 3 experiments in each strain. (B) Irradiated B6D2F₁ mice received whole spleen from G-CSF–mobilized B6 allogeneic donors, followed by control diluent, C20:2, or KRN7000 IP on day +1 and hepatic NK (NK1.1⁺CD3^neg)- and T-cell (CD3^posNK1.1^neg) subsets enumerated 24 and 48 hours after glycolipid injection. Mean ± SE from 5 to 7 mice per group. *P < .05 vs control diluent; **P < .05 vs control diluent and C20:2. (C) Irradiated B6D2F₁ mice received whole CFSE-labeled spleen from G-CSF–mobilized B6 allogeneic donors, followed by control diluent, C20:2, or KRN7000 IP on day +1. Proliferation of liver NK cells was determined by CFSE dilution on day +3. Proliferation indices of individual mice were determined by Modfit analysis and are shown as mean ± SE (n = 5 per group). Representative CFSE fluorescence-activated cell sorter (FACS) plots are also shown. *P < .02 vs control diluent. (D) Irradiated CD45.2⁺ B6D2F₁ mice received whole spleen from CD45.1⁺ G-CSF–mobilized B6 allogeneic donors, followed by control diluent, C20:2, or KRN7000 IP on days +1 and +4. Donor engraftment (CD45.1⁺CD45.2^neg) in NK- and T-cell subsets (gated as above) was determined at day +5 in hepatic lymphocytes pooled from 4 to 5 mice per group.