Sequence analysis of a novel human leukocyte antigen allele B*5827 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the molecular basis for a novel human leukocyte antigen (HLA) allele B*5827.</p><p><b>METHODS</b>DNA from the proband was analyzed by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) typing. The amplified product was sequenced bidirectionally.</p><p><b>RESULTS</b>Abnormal HLA-B locus was observed and its nucleotide sequence was different from the known HLA-B allele sequences, with highest homology to HLA-B*5820 allele. It differs from HLA-B*5820 by 8 nucleotide substitutions in exon 3, i.e., nt 290 (G > C), nt 346 (T > A), nt 390 (A > C), nt 404 (G > C), nt 413 (C > G), nt 471 (A > G), nt 486 (A > G) and nt 487 (C > A), resulting in an amino acid change from ser > arg at nt 97, phe >tyr at nt 115, ser > arg at nt 130, thr > ala at nt 157 and thr > glu at nt 162. Nucleotide differences of nt 404 (G > C) and nt 413( C > G) did not change amino acid.</p><p><b>CONCLUSION</b>The sequences of the novel allele have been submitted to GenBank (access No.GU071234). A novel HLA class I allele B*5827 has been officially assigned by the WHO HLA Nomenclature Committee in Jan. 2010.</p>

In vitro expansion and function of cord blood megakaryocyte / 中华儿科杂志

<p><b>OBJECTIVE</b>Cord blood (CB) provides a rich source of stem cells for transplantation. CB transplantation has been used widely after myeloablative therapy. One major disadvantage of CB transplantation is delayed platelet engraftment. The aim of this study was to hasten platelet engraftment by investigating the ability of different hematopoietic growth factor combinations to generate large numbers of megakaryocyte (Mk) from CB and by evaluating the biologic characteristics and function of the expanded Mk.</p><p><b>METHODS</b>CB samples were obtained at the end of normal full-term deliveries with informed consent. Mononuclear cells (MNCs) were isolated from CB using Ficoll density centrifugation. MNC population was positively selected for CD(34) expression by magnetic cell sorting (MACS). CD(34)(+) cells were cultured in serum-free and stroma-free medium containing the following two different cytokine combinations: thrombopoietin (TPO) + stem cell factor (SCF) + interleukin (IL) -3 + IL-6 and TPO + SCF. Cultures were characterized after 3, 7, 10 and 14 days by flow cytometry, colony forming unit-megakaryocyte (CFU-Mk) and maturation evaluation (Mk ploidy). The expanded Mk function was examined by the platelet activation in vitro and severe combined immunodiffiency (SCID) mice transplantation in vivo.</p><p><b>RESULTS</b>Different results were observed with different culture conditions. With the first cytokine combination optimal expansion of CD(41)(+) cells was observed on day 10, but the optimal expansion of Mk progenitors (CD(34)(+)CD(41)(+)) was observed on day 7, with a median 121 and 44-fold increase at the starting cell dose. This result was also proven by CFU-Mk. The largest numbers of CFU-Mk were also observed on day 7. The degree of maturation of Mk cells also increased as suggested by DNA content of CD(41)(+) cells, which means that CD(34)(+) cells cultured for 3 - 7 days were richer in primitive Mks, while those cultured for 10 - 14 days had greater numbers of more differentiated Mks. For the second cytokine combination, CD(41)(+) and CD(34)(+)CD(41)(+) cells were fewer than the first one, but it produced 36 and 85-fold CD(34)(+)CD(41)(+) and CD(41)(+) respectively on day 7. Platelet activation test confirmed that the expanded Mks had normal function. Therefore, the expanded Mks could be transplanted into the SCID mice bone marrow and produce human platelet in the peripheral blood of the mice.</p><p><b>CONCLUSION</b>Ex vivo expanded Mk might facilitate CB transplantation and help shorten the period of post-transplant thrombocytopenia.</p>

Study of single cell PCR for HLA typing / 中华血液学杂志

<p><b>OBJECTIVE</b>To apply the single cell nested multiplex polymerase chain reaction (PCR) to HLA typing, and analyze the influence factors on the amplification results.</p><p><b>METHODS</b>Single cell DNA templates were prepared with different methods. The exon 2, 3 and intron 2 of HLA-A, B, and exon 2 of DRBI were amplified using multiplex PCR. The second round of SSP-PCR HLA typing was carried out according to the large scale routine HLA typing results.</p><p><b>RESULTS</b>Enzyme lysis method was the most efficient procedure for preparing the single cell DNA template, with a success rate (SR) of 93.3%, while the SRs of alkali lysis and freezing-thaw lysis methods were 83.3% and 73.3%, respectively. The second round amplification using enzyme lysis and SSP-PCR in 20 samples obtained a 95% success rate and a 15% allele drop out rate. The time for performing the whole procedure was less than 6 hours.</p><p><b>CONCLUSION</b>The modified nested multiplex PCR technique is efficient for single cell HLA typing and might be applied to clinical preimplantation genetic diagnosis.</p>

Biological characteristics of rabbit bone marrow mesenchymal stem cells and their response to different growth factors / 中国实验血液学杂志

This study was aimed to analyze the biological characteristics of rabbit bone marrow mesenchymal stem cells (rBM-MSCs) and their response to different growth factors. Rabbit BM-MSCs were separated from bone marrow mononuclear cells by using adherent cultivation. Biological characteristics were investigated by optical and electron microscopy. Immunophenotype of rBM-MSCs was measured by flow cytometry. The expression of collagen was detected by RT-PCR. Differentiation potential was identified by specific staining and RT-PCR. The response of rBM-MSCs to IL-1, 3, 8 and HGF with different concentrations were tested by MTT. The results showed that the rBM-MSCs gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast-like morphology and could be cultured for over 15 passages. CD44 was highly expressed on F5 rBM-MSCs (32%) and CD45 was lowly expressed (4.7%). Type I collagen was highly expressed, while type II collagen was lowly expressed and type X collagen was not detected on rBM-MSCs using RT-PCR method. In various conditions inducting differentiation, rBM-MSCs could differentiate into the osteoblast, chondrocyte, adipocyte and neuron-like cells. The rBM-MSCs were sensitive to IL-3, even low concentration (10 ng/ml) of IL-3 could promote the proliferation of rBM-MSCs effectively (>32%, P < 0.01), whereas high concentration IL-3 inhibited it significantly. It is concluded that rabbit BM-MSCs were successfully isolated and culture-expanded. The biological characteristics of rabbit BM-MSCs are similar to those of human and rhesus BM-MSCs. IL-3 with low concentration can promote the proliferation of rBM-MSCs effectively, but high concentration of IL-3 can inhibit their proliferation.

Differentiating ability of non-hematopoietic adult stem cells from rat fetal blood and bone marrow in vitro / 中国实验血液学杂志

To compare the growth characteristics of non-hematopoietic adult stem cells (NASC) derived from rat fetal blood and rat bone marrow in vitro, and to study the differentiation of these stem cells into neuron-like cells in vitro, the fetal blood of pregnant rats and bone marrow of adult rats were sterilely collected; mononuclear cells (MNC) were isolated by using standard Ficoll-hypague techniques and then cultured in DMEM/LG containing 10% fetal bovine serum (FBS). The acquired NASCs were subcultured for passage. The immunophenotype of NASCs was detected by flow cytometry. The expanded NASCs were induced to differentiate into neurons-like cells by beta-mercaptoethanol (beta-ME), dimethylsulfoxide (DMSO), butylated hydroxyanisole (BHA). The specific markers of these neuron-like cells were detected by immunocytochemistry. The results showed that two kinds of subcultured NASCs showed homogeneous spindle-shaped and expressed antigens CD44 and CD54, but did not expressed CD11b and CD45. The both induced cells were similar to neuron in morphology and were positive for nestin and neuron-specific enolase (NSE), but negative for glial fibrillary acidic protein (GFAP). It is concluded that no significant difference of NASCs derived from pregnant rat fetal blood and adult rat bone marrow found in cell morphology and biological characteristics. NASCs of both origins can be induced to differentiate into neuron-like cells, so fetal blood can be regarded as another resource of NASC.

Biological characteristics and induced differentiation ability of in vitro expanded umbilical cord blood mesenchymal stem cells / 中华儿科杂志

<p><b>OBJECTIVE</b>Mesenchymal stem cells (MSCs) from bone marrow are capable of differentiating into cells of different tissue lineages such as bone, cartilage, and adipose tissue and are the best candidates for tissue engineering. It is well accepted that umbilical cord blood (UCB) is a source for hematopoietic stem cells. However, controversy exists as to whether UCB contains MSCs and can serve as a source of MSCs. Therefore, the aim of this study was to explore the biological characteristics and inducing differentiation ability of in vitro expanded UCB MSCs.</p><p><b>METHODS</b>UCB was collected on normal full term delivery of infants with informed consent (n = 35) obtained from the mothers. Mononuclear cells (MNCs) were isolated from UCB by gravity centrifugation and cultured with DMEM including 10% fetal bovine serum. The morphology was observed under microscope per day. Cytochemical staining was carried out and flow cytometry was used to examine the surface antigen phenotype. Fifth passage cells were transferred into a different medium and osteogenic differentiation, adipogenic differentiation, and neurogenic differentiation were assessed.</p><p><b>RESULTS</b>MSCs could be isolated and cultured from MNCs of a few UCB sources. These cells displayed fibroblast-like morphology. They withstood over 20 passages without significant structural changes. These MSCs were negative for alkaline phosphatase (ALP) staining and positive for alpha-naphthol butyric acid esterase (NBE) staining. Expression of CD(29), CD(44)and CD(105), especially the human MSCs-specific markers SH-2 and SH-3 were observed, but CD(3), CD(14), CD(19), CD(34) and CD(45) could not be found, indicating that these cells were not of hematopoietic origin. Exposure of these MSCs to serum-free osteogenic condition, they could differentiate into bone cells and form mineralized matrix as evidenced by Alizarin red staining 2 weeks later. When these UCB-derived MSCs were cultured in adipogenic medium, morphologic changes in cells as well as the formation of neutral lipid vacuoles were noticeable as early as 1 week after induction and visualized by staining with oil-red O. Surprisingly, these MSCs were also able to differentiate into neuroglial-like cells. Morphology of these induced cells resembled that of neurons. Immunocytochemistry showed that they expressed Nestin and neuron-specific enolase (NSE), but not glial fibrillary acidic protein (GFAP).</p><p><b>CONCLUSION</b>UCB does contain MSCs. These MSCs, which are multipotent, could be isolated and cultured from a few UCB sources. UCB might serve as an alternative source of MSCs to bone marrow.</p>

Effect of total glucosides of paeony on the proliferation of fibroblast-like synovial cells in osteoarthritis / 中华风湿病学杂志

Objective To investigate the proliferative characteristics of fibroblast-like synovial cells (FLS)in osteoarthritis in vitro and the mechanism of the immunosuppressive effect of total glucusides of paeony(TGP).Methods FLS of OA and non-inflamed synovium(NS)were cultured and identified in vitro in the presence or absence of TGP.After incubation,the survival fraction(SF)of FLS was evaluated by MTI' and the TNF-?,IFN-?and bFGF level in cultured FLS supernatant was measured by ELISA.The expression of FLS c-los mRNA and cell cycle of OA-FLS was observed by RT-PCR and flow eytometry respectively at the same time.Results No statistical significant differences were noted between the OA and NS FLS in pro- liferating double time.High doses of TGP suppressed FLS-SF more evidently in OA patients than in NS(P0.05).Conclusion High dose TGP can inhibit OA-FLS proliferation,modulate cy- tokine secretion and c-fos expression in OA.This suggests that TGP has immunosuppressive effect on OA syn- ovitis,probably by preventing the synovial hypertrophy in OA.

Effect of T-614 on proliferation characteristics of fibroblast like synovial cells in osteoarthritis / 中华风湿病学杂志

Objective To investigate the proliferation characteristics of fibroblast like synovial cells (FLS)in osteoarthritis in vitro and the mechanism of the immnnosuppressive effect of T-614 [N-(3-formy- lamino-4-oxo-6-phenoxy-4H-chromen-7-yl)methanesulfonamide ] on them.Methods FLS of OA and non- inflamed synovium(NS)were cultured and identified in vitro in the presence or absence of T-614.After incu- bation,the survival fraction(SF)of FLS was evaluated by MTT,cell cycle was observed using fluorescence - activated cell sorting(FCS)method and the expression of c-fos and COX-2 mRNA was examined by RT- PCR in FLS of OA patients.Results No statistically significant difference was noted between the OA and NS FLS in proliferation ability and cell cycle.High dose T-614 suppressed FLS SF obviously in OA and NS sta- tistically(P＜0.05),whereas the inhibition degree was not different between the two kinds of FLS.The agent induced cell apoptosis and reduced the accumulation of c-fos mRNA in OA-FLS at dose 1000 ml/L,prolonged G_1 term and shortened S term at dose 200 ml/L.The expression of COX-2 mRNA in OA FLS was suppressed obviously by T-614 at dose 1000 ml/L.Conclusion OA FLS do not display a distinct activated unlimited viability compared with NS cells,without stimulated by proinflammatory cytokine in vitro.High dose T-614 moderately inhibits the proliferation and differentiation of FLS,directly affects gene of the c-fos and COX-2 expression in OA,which may contribute to its immunosuppressive effect on OA'synovitis.

Double chimerism in recipient by transplantation of two allogeneic MHC-mismatched mouse fetal blood units / 中国实验血液学杂志

We have constituted a mouse model for fetal blood transplantation (FBT) to cross over major histocompatibility complex (MHC) without causing serious GVHD. It seems that full matching at the MHC appears not necessary for FBT, while the nucleated cell dose is critical. Two fetal blood units were combined from different donors to increase the stem/progenitor cell dose so as to explore the possibility of MHC-mismatched allogeneic transplantation. 26 out of 40 mice in mixed FBT group survived in the observation period of 60 days after transplantation without obvious GVHD. Double chimerism was demonstrated by PCR and flow cytometric analysis; and skin transplantation test proved the induction of donor specific immune tolerance. Our data suggest that two MHC-mismatched allogeneic donor fetal blood units could simultaneously engraft and reconstitute immune and hematopoietic system in a mouse model. The result may be beneficial for the expansion of cord blood application and enables more patients to share the advantages of cord blood transplantation.