Study on the analysis of high-resolution HLA-A,B and DRB1 alleles from 3238 hematopoietic stem cell donors in Jiangsu Han Chinese / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the genetic polymorphism, distribution of haplotypes, common and well-documented (CWD) and rare alleles of high-resolution HLA-A, B and DRB1 alleles by analysis from hematopoietic stem cell (HSC) donors in Jiangsu Han Chinese.</p><p><b>METHODS</b>PCR-sequence-based typing and PCR-sequence specific oligonucleotide probes methods were applied for HLA-A, B and DRB1 high-resolution genotyping of 3238 unrelated healthy donors of hematopoietic stem cells in Jiangsu branch of Chinese National Marrow Donor Program registry.</p><p><b>RESULTS</b>46 alleles of HLA-A,85 HLA-B and 51 HLA-DRB1 locus were found. The frequencies of the most common alleles were A * 11:01 (16.52%), B * 13:02 (11.60%) and DRB1 *07:01 (15.78%). That of the most common haplotype was A * 30: 01-B * 13: 02-DRB1 * 07: 01 (8.87%). 40 alleles of HLA-A,77 alleles of HLA-B, and 47 HLA-DRB1 alleles of HLA-DRB1 were CWD, which account for 99. 8% of total number of samples, and a few rare alleles not reported in Chinese population were found.</p><p><b>CONCLUSION</b>The results of high-resolution, CWD and rare alleles showed the characteristics of HLA distribution in Jiangsu Han population, which may be useful for finding HLA matched unrelated donors, as well as for HLA correlation with population genetics and disease association studies.</p>

Proteasome inhibitor bortezomib inducing apoptosis of K562 cells not affected by bone marrow mesenchymal stem cells in vitro / 中国实验血液学杂志

The study was aimed to investigate the effects of proteasome inhibitor bortezomib on the apoptosis of K562 cells in the presence of bone marrow mesenchymal stem cells, and explore its effect on expression of adhesion molecule VCAM-1 of both MSC and K562 cells. The K562 cells were co-cultured in direct contact with MSC, while the control cells were just cultured alone. Bortezomib was administered at a final concentration of 50 nmol/L. Cell apoptosis was assayed by flow cytometry with Annexin-V/PI double staining kit. The VCAM-1 gene expression was determined by reverse transcription polymerase chain reaction (RT-PCR). The results indicated that bortezomib could induce apoptosis of K562 cells in a time-dependent manner. K562 cells growing on the layer of MSC demonstrated the similar sensitivity to apoptosis induction of bortezomib. K562 cells which did not express VCAM-1 originally were induced to express VCAM-1 mRNA when co-cultured with MSC. This effect could be abrogated by bortezomib treatment. Furthermore, bortezomib significantly downregulated the VCAM-1 expression of MSC. It is concluded that the proteasome inhibitor bortezomib can induce apoptosis of K562 cells even though in presence of the MSC layer.

Human bone marrow stromal cells facilitate the cord blood CD34+ cells ex vivo expansion and short-term engraftment in NOD/SCID mice / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the potential of human bone marrow stromal cells (MSCs) as the feeding-layer to promote ex vivo expansion of cord blood CD34+ cells and engraftment of the expanded cells in NOD/SCID mice.</p><p><b>METHODS</b>Human MSCs were routinely isolated and cultured. MSCs at passage 3 were used as feeding-layer for the expansion of cord blood CD34+ cell in the presence of thrombopoietin (TPO), flt3/flk2 ligand (FL), stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF). The engraftment potential between unexpanded and expanded cord blood cells transplanted into NOD/SCID mice was compared.</p><p><b>RESULTS</b>The total nucleated cells (TNC), CD34 cells and colony forming units (CFUs) in the MSC feeding culture were increased by 111.6-, 19.3- and 58-fold after 1 week expansion and 532.8-, 41.3- and 563.5- fold increased after 2 weeks expansion respectively as compared with that in non MSC feeding culture. In transplant experiment, the percentage of human CD45+ cells (45.3% -59.1%) in bone marrow of recipient mice transplanted with the MSC feeding expanded cells was the highest in all the groups at six weeks after transplantation.</p><p><b>CONCLUSION</b>Human MSCs enhance CB CD34+ cells in vitro expansion and their capacity of short-term engraftment in NOD/SCID mice.</p>

Effect of co-culture of bone marrow mesenchymal stem cells and K562 cells on expression of interleukin 8 / 中国实验血液学杂志

To investigate the effects of interaction between human bone marrow mesenchymal stem cells (MSCs) and K562 cells on the expression of proangiogenic factor IL-8, the K562 cells were co-cultured in direct contact with MSCs or cultured in MSCs conditioned medium while the controlled K562 cells were cultured alone. The IL-8 gene expression of K562 cells and MSCs was determined by RT-PCR. The results indicated that the expression of IL-8 in K562 cells when co-cultured in direct contact with MSCs or cultured in MSCs conditioned medium was obviously higher than that of K562 cells cultured alone (p<0.01). MSCs co-cultured with K562 cells also had an increased level of IL-8 compared with MSCs cultured alone (p<0.01). It is concluded that the interaction between MSCs and K562 cells via direct contact and the cytokine network promotes expression of IL-8.

The population genetics study in HLA field / 中华医学遗传学杂志

Human leukocyte antigen (HLA) is the most polymorphic genetic system found in human genome. The polymorphisms of different HLA genes and haplotypes in different ethnic and geographic populations are of high importance for investigation of their population genetic characteristics and searching for HLA matched unrelated hematopoietic stem cell transplantation donors, as well as in disease association studies. The HLA molecular genetic principals and the progress of HLA population investigation were reviewed, as well as the methods applied in the field.

Expression of HOXB4 in cord blood progenitor cells expanded in vitro / 中国实验血液学杂志

HOXB4, a member of homeobox gene family, is closely related to the self-renewing and proliferative ability of primitive hematopoietic stem/progenitor cells (PHSC/PHPC). This study was aimed to investigate the self-renewing level of cord blood progenitor cells (CBPC) expanded in vitro. The HOXB4 expression at mRNA level was assayed by using real time RT-PCR. The results indicated that as culture prolonged, the total cells, CD34(+) cells greatly increased, however the HOXB4 expression gradually declined, even down to undetectable level similar to that of mature lymphocytes. Meanwhile, it was shown that CD34(+) cells co-cultured with bone marrow mesenchymal stem cells (BM-MSC) could abate the decline of HOXB4 expression. It is concluded that the self-renewing potential of CD34(+) cells gradually decreased during expansion in vitro, co-culture with BM-MSC was helpful to CD34(+) cell expansion and slowed the loss trend of its self-renewal.

HOXB gene family and functions of hematopoietic stem/progenitor cells--review / 中国实验血液学杂志

Recently, many researches indicated the important role played by homeobox (HOX) gene family in normal hematopoiesis. As a kind of transcription factors, HOX gene products regulate and control the expression of target genes by binding to special DNA sequences. HOXB, a member of HOX gene family, especially HOXB(4), interests people greatly. It has been found that its expression relates closely to the self-renewal of hematopoietic stem cells and effective proliferation of hematopoietic progenitor cells. This review presents some new research progress in this area.

Human bone marrow mesenchymal stem cells express multiple hematopoietic growth factors / 中国实验血液学杂志

To study the biological role of human cultured bone marrow mesenchymal stem cell (BM-MSC) in hematopoiesis by investigation of its expression of multiple hematopoietic growth factors, RT-PCR was used to analyze the expression of SCF, Flt3-ligand, TPO, LIF, G-CSF, GM-CSF, IL-3, IL-6 and IL-11 at mRNA level for human BM-MSC from healthy donors and patients with leukemia and lymphoma. BM-MSC were incubated with or without hydrocortison (HC). The results clearly showed that the cultured BM-MSC expressed mRNA of SCF, Flt3-ligand, TPO, LIF, IL-6 and IL-11 at passages 3 up to 15, but did not express G-CSF, GM-CSF and IL-3. The same expression pattern of above cytokines was seen also for the patient's BM-MSC. HC was able to induce BM-MSC to express G-CSF but not to express GM-CSF. BM-MSC seemed not to change morphologically after incubation with HC for up to 21 days. In conclusion, both normal and patient BM-MSC should be potential to promote hematopoiesis according to their expression of multiple hematopoietic cytokines, and HC is able to induce hematopoietic growth factor expression.