KLRE-1 plays a pivotal role in allogeneic bone marrow transfer. (A) Cytotoxic activity against allogeneic Con A blasts using KLRE-1–deficient cells. Cytolytic activity of LAK cells containing activated NK cells from wild-type C57BL/6 (WT, ▵) and KLRE-1–deficient (KLRE-1 KO, ▪) mice was assessed. Representative data from 3 independent experiments (n = 5/experiments) are shown as means ± SD. (B-C) KLRE-1 KO mice fail to reject BM allograft. (B) BALB/c BM cells (1 × 106 or 3 × 106 cells) or C57BL/6 BM cells (1 × 105 cells) were intravenously infused to lethally irradiated age-matched wild-type or KLRE-1–deficient C57BL/6 mice. At 8 days after transplantation, spleens were removed and the number of colonies on the spleen was counted. Representative data from the 3 independent experiments are shown. Data are indicated as means ± SD of 5 individuals per experiments. (C) Representative picture of allograft-induced colony formation in the spleen of KLRE-1 knock-out mice. Colony formation resulting from the BALB/c BM allograft as described in panel B can be observed on the spleen of lethally irradiated KLRE-1 null mice (KO), but not on that of C57BL/6 mice (WT) after the fixation in the Bouin solution. The photo was taken with a Nikon digital camera (Cool Pix 995) and processed with Adobe Photoshop.
