Besides HSCs, there also existed another kind of stem cells called MSCs (Mesenchymal Stem Cells), they could differentiated into stroma cells and acted as the “”niche”" in the micro-environment[24]. MSCs also had the immunological regulation ability and were believed to be the “”immune protection site”" in the cells environment. So, we believed that MSCs might play selleck inhibitor important role in the pathogenesis of CML,

but there was no article examined the immunological function of MSCs. Previous studies[19, 21] from our laboratory have identified Flk1+ (fetal liver kinase-1 positive) CD31-CD34- cells carrying the BCR/ABL fusion gene from the bone marrow of Philadelphia chromosome positive (Ph+) patients with CML and found that these cells could differentiate into malignant blood cells and phenotypically defined endothelial cells at the single-cell level, suggesting these cells have

the properties of hemangioblasts. The main purpose PD0325901 datasheet of our article was to examine the immune characteristics of Flk1+CD31-CD34- MSC in CML and analyse if there existed abnormalities comparing with the healthy donors. Patients, materials, and methods Patient samples 20 patients with newly diagnosed CML (12 male and 8 female, aged 17-63 years) were recruited in this study(table 1). All were Ph+ patients with CML in chronic phase as revealed by bone marrow histology and cytogenetic analysis. The immunophenotypes of thawed cells were quite variable. None was treated with hydroxyurea or interferon before. The control samples were from 20 healthy donors (12 male and 8 female, aged 21-60 years). Bone marrow samples were collected after obtaining informed consent according to procedures approved by the Ethics Committee at the 309th Hospital of Peoples Liberation Army. Table 1 The general conditions of the patients Patient Age Sex Diagonosis Diagnosis time Ph chromosome Immunosuppressive therapy 1 84 F CML Aug-04 positive

yes 2 54 M CML Jun-87 positive yes 3 56 M CML May-99 positive yes 4 49 M CML Feb-87 positive yes 5 66 M CML Aug-04 positive yes Ibrutinib in vitro 6 40 F CML Feb-05 positive No 7 50 F CML Sep-04 positive No 8 76 F CML Aug-04 positive No 9 64 F CML Dec-05 positive No 10 55 M CML Apr-00 positive yes 11 49 M CML Feb-05 positive No 12 51 M CML Jun-01 positive yes 13 40 F CML Dec-05 positive No 14 43 F CML Dec-05 positive No 15 60 M CML Nov-05 positive No M: male; F:female; Cell preparations and culture Isolation and culture of bone marrow-derived CML hemangioblasts were performed as described previously with some modifications[19, 21]. Briefly, mononuclear cells were separated by a Ficoll-Paque gradient centrifugation (specific gravity 1.077 g/mL; Nycomed Pharma AS, Oslo, Norway) and the sorted cells were plated at concentration of 1 cell/well by limiting dilution in a total of 96 × 10 wells coated with fibronectin (Sigma, St Louis, MO) and collagen (Sigma) for each patient.