SLAM family predicting the initiation potential of human acute lymphoblastic leukemia in NOD/SCID mice

Background The SLAM family recently has been reported to show an important biological role in lymphocytedevelopment and immunological function,and it is efficient to highly purify hematopoietic stem cells using a simplecombination of SLAM family members.To elucidate the presence of this family on acute lymphoblastic leukemia(ALL),as well as its relationship with the leukemia-initiating potential,we analyzed the expression pattern of this familymembers on human ALL progenitor cells,combined with serial xenotransplantation assay.Methods Expression analysis was carried out by flow cytometry.We combined the expression pattern of human CD,CDand CDwith serial xenotransplantation of B-ALL progenitor cells to indicate their relationship.Results CDand CDwere expressed on most B-ALL progenitor cells,the percentage being(93.08±6.46)% and(63.37±29.31)%,respectively.Interestingly,the proportion of CD~+cells declined obviously in engrafted cases((24.94±7.32)%)compared with non-engrafted cases((77.54±5.93)%,P<0.01),which indicated that only blast cells withlow percentage of CD~+population were able to reconstitute leukemia into primary,secondary and tertiary NOD/SCIDmice.Conclusions SLAM family members are present on B-ALL progenitor cells and the leukemia-initiating potential ofleukemic blasts is correlated negatively with the proportion of CD~+cells,the percentage of which can serve as a usefulpredictor for engraftment success of B-ALL to immune deficient mice.