Comparable rates of engraftment into primary, secondary, and tertiary recipient mice.
Primary leukemia cells from patient 3 were inoculated into a group of 4 irradiated mice, and engraftment monitored as described in “Patients and methods.” At death, spleens were minced and mononuclear cells purified by density gradient centrifugation and cryopreserved. Subsequently, cells were retrieved from cryostorage and 4 secondary recipient mice were inoculated and monitored for engraftment. When engrafted, the process of harvesting cells from spleens and inoculating tertiary recipient mice was repeated. Primary (open circles, solid line), secondary (closed circles, dotted line), and tertiary (open triangles, dashed line) recipient mice were inoculated with equal numbers of human leukemia cells (3.5 × 106). Individual data points are shown ± SD.
