CpG ODN treatment reduces B-CLL cell engrafted in NOD-scid mouse xenograft models. (A) B-CLL cells with or without CpG 2006 pretreatment for 2 days were intraperitoneally injected into NOD-scid mice. After 5 days, B-CLL cells engrafted within the peritoneal cavity and spleen of NOD-scid mice were harvested and determined. (B) NOD-scid mice were intraperitoneally injected with fresh B-CLL cells followed by 5 daily intraperitoneal injections of CpG 2006 or PBS. After 5 days, the number of B-CLL cells within host peritoneal cavity and spleen were harvested and determined. (A-B) Results from 5 mice per group with B-CLL cells derived from different patients. Each dot represents an individual mouse, and the horizontal bar represents the median level. *P < .01, the number of B-CLL cells in mice with versus without CpG 2006 treatments. Naive NOD-scid mice were used as control.