Ex vivo expansion of T, NK and CD34+ cells from umbilical cord blood.

Umbilical cord blood stem cell transplantation (CBSCT) has made significant progress in treatment of lethal congenital or malignant disorders. Both the incidence and severity of GVHD from CBSCT were lower than that from bone marrow and peripheral blood stem cell transplantation, particularly for adult patients, but these advantages were also associated with higher rates of relapse. The immune-mediated effect of natural killer and cytotoxic T cells against residual tumor cells were shown to prevent relapse and to induce remission after bone marrow transplantation.

Establishment of a transplantable human myeloid BALB/c nude mouse model.

To establish a mouse model bearing transplantable human chronic myeloid leukemia for hematopoietic stem cell transplantation to treat leukemia, 4 - 5-week-old female BALB/c nude mice were given cyclophosphamide 2 mg/mouse at day -2, -1, and then the human chronic myeloid leukemia K562 cells were engrafted into the mice at day 0 by injection via tail vein or peritoneal cavity. PB and BM cells were collected, the CD45, CD13, and CD33 antigens were delected by using FCM, the bcr/abl fusion gene mRNA was examined by RT-PCR. The results showed that transplantable leukemic mice could be yielded from 4 - 5-week-old nude mice either by injection through tail vein or peritoneal cavity when the total number of inoculated tumor cells was more than 2 x 10(5) per mouse, whether being pretreated with 2 mg CTX/mouse or not.