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标题: Fast But Durable Megakaryocyte Repopulation and Platelet Production in NOD/SCID [打印本页]

作者: 江边孤钓    时间: 2009-3-5 10:38     标题: Fast But Durable Megakaryocyte Repopulation and Platelet Production in NOD/SCID

a Department of Oncological Sciences, University of Torino Medical School,4 ~' N3 t, J; X
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b Division of Clinical Oncology, Institute for Cancer Research and Treatment, Candiolo, Torino, Italy;
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c The Pediatric Department, University of Torino Medical School, Torino, Italy
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/ g. R4 ?5 j8 I6 n& Y: mKey Words. Cord blood ? CD34  cell expansion ? NOD/SCID ? Megakaryocyte engraftment
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- o! u/ \0 u1 ]" q8 K, eWanda Piacibello, M.D., University of Torino Medical School, Department of Oncological Sciences, Institute for Cancer Research and Treatment, Laboratory of Clinical Oncology, Prov. 142, 10060 Candiolo, Torino, Italy. Telephone: 39-011-9933349; Fax: 39-011-9933522; e-mail: wanda.piacibello@ircc.it
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* {) [  `8 }; m$ ~( ^& GABSTRACT2 l" K7 Z! J9 @" v; O

& |  J  o% y9 s  MThe numbers of hematopoietic progenitors and stem cells in cord blood (CB) may be enough to support engraftment in children, but their ex-vivo expansion might be required to successfully engraft an adult. Moreover, a long-lasting severe post-transplant thrombocytopenia is often observed even in pediatric patients .; p+ _2 u0 ^1 r( S
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Therefore, two important aspects of the biology of ex-vivo expanded cells relate to cultured cells: either maintaining their self-renewal capacity and multilineage differentiation potential, or improving their short-term engraftment ability when transplanted into myeloablated recipients. Several growth factor combinations have been tested to identify suitable culture conditions to induce expansion of primitive stem cells (SCs). So far, only a few studies have shown that primitive non-obese diabetic severe combined immunodeficient (NOD/SCID) mouse repopulating stem cells from CB can be expanded (a few or several-fold) after in vitro culture .( k. h2 i7 e! K( n+ I
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In CB transplants, the megakaryocyte (Mk) lineage takes the longest time to engraft. However, to date, if only a few experimental studies have addressed the issue of the short-term engraftment ability of fresh CB SCs, even fewer have addressed that of ex-vivo expanded SCs . Using the NOD/SCID mouse model, the short-term as well as the long-term repopulating ability and the differentiation and maturation potential of human hematopoietic lineages in an in vivo experimental model can be analyzed .
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/ k2 A4 D; W2 i; oThus, by means of this in vivo model we set up experiments to evaluate the Mk lineage reconstitution ability and functional platelet release by baseline CB CD34  cells (b34 ) and CB CD34  cells reisolated after a 4-week expansion (4w34 ) in the presence of Flt-3 ligand (FL), thrombopoietin (TPO), and stem cell factor (SCF).
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% K* V9 l% d/ {6 k9 H/ F5 k8 L' uMATERIALS AND METHODS
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4 _0 v( o0 S) O- M- A! AMegakaryocyte Reconstitution in NOD/SCID Mice by Baseline and Expanded CD34  Cells (b34  and 4w34 )
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7 u, e& ~) N$ b) H0 k1 I: jTo evaluate short-term Mk-engraftment, 2.5 x 105 b34  cells were injected into cohorts of sublethally irradiated NOD/SCID mice that were sacrificed 1, 2, and 3 weeks after inoculation. BM cells of the sacrificed animals were obtained from both femurs and tibias and assessed for the presence of human hematopoietic cells. Human cells in the murine BM were quantified for myeloid, lymphoid, erythroid, and Mk lineage antigen expression. Fluorescence-activated cell sorter (FACS) analysis of the BM of the sacrificed animals showed that at week 1 post-transplant levels of human CD45  cells were low but clearly detectable (3.7 ± 2.8). Within the human cells, the most represented were the CD34  and the CD19  subpopulations (Table 1). Erythroid cells, identified by CD71 and GpA expression were also present. Surprisingly, no cells belonging to the Mk lineage could be found. At week 2 post injection, the levels of human CD45  cells were quite similar. At week 3, human cell engraftment further increased. Only at this time point the Mk subpopulation, although at very low percentages, became detectable (Table 1).8 z( T+ k8 g6 I# m# i6 F0 A

+ e( {) \; _8 B1 Z+ e6 iTable 1. Short-term engraftment of NOD/SCID mice transplanted with fresh (b34 ) or ex vivo expanded (4w34 ) cells. j* Q5 l# j4 f2 ~9 U
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To evaluate the short-term Mk-engraftment capacity of more expanded primitive cells, in five different experiments, 2.5 x 105 CD34  cells were cultured in triplicate stroma-free liquid cultures in the presence of FL, SCF, and TPO as described . After 4 weeks of expansion they yielded a mean of 48.5 ± 2.4 x 106 total cells that included 1.9 ± 0.43 x 106 CD34  cells. Following immunoselection, only 2.5 x 105 CD34  (4w34 ) cells were injected in each mouse. In these mice the levels of human engraftment at week 1 were similar to those found in b34 -transplanted mice and increased with time. Here the growth of some CFU-Mk colonies could be achieved. CFU-Mk number increased at weeks 2 and 3 (Table 1). By contrast, in mice injected with b34  cells, no CFU-Mk colonies could be found at week 1. Only at week 3 were there as many Mk colonies as those found much earlier (week 1) in 4w34  transplanted mice.
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Long-term Mk-engraftment was evaluated in NOD/SCID mice sacrificed 6–8 weeks after inoculation. Table 2 shows the mean engraftment level of ten mice injected with 2.5 x 105 b34  cells. Flow cytometry analysis showed that the human cells belonged to all hematopoietic lineages; cells of the Mk lineage were found in all mice. CFU-Mk colonies were detected in plasma clot cultures seeded with the BM cells of the transplanted animals (Table 2).
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Table 2. Six- to 8-week engraftment of NOD/SCID mice transplanted with b34  and 4w34  CB cells
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: b- L4 ]& _+ c) l9 K* l2 zThe results of injection of 2.5 x 105 4w34  cells are reported in Table 2. All the mice, after 6–8 weeks from the injection, were successfully engrafted (10/10). The mean engraftment level of the ten mice injected with this cell dose was 15 ± 5%. FACS analysis showed that human cells belonged to all hematopoietic lineages (not shown).+ J" x8 H1 s5 g% [1 r
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Moreover, five mice were transplanted with all of the CD34  cells generated by initial 2.5 x 105 CD34  cells during a 4-week expansion. At 6–8 weeks post-transplant the BM engraftment levels were very high (79 ± 11.4) and the Mk population was well-represented (3.6 ± 0.4% of the total BM).* ?# ?+ X/ y$ O" Z9 G' h9 M: c
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The presence of human CFU-Mk in the BM of mice was evaluated. Overall, 1,900 ± 302, 2,200 ± 159 and 8,259 ± 1,102 human Mk colonies were detected in mice transplanted with b34  and the two concentrations of 4w34  cells, respectively.# n  S. }( q: ]6 L# ^' O& o& [$ L
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To evaluate the effective long-term Mk-engraftment of expanded cells, the unseparated BM cells of three primary mice, harvested 6 weeks after injection of 2.5 x 105 4w34  cells, were transplanted in three secondary and subsequently in three tertiary sublethally irradiated recipients. In these experiments of serial transplants, mice were successfully engrafted, and the Mk population was well-represented  (Fig. 1).. S% d2 k# T) v9 H0 R8 ?

$ K+ }9 Q7 n7 ^9 w6 t/ }Figure 1. Human megakaryocyte engraftment in serial transplant NOD/SCID mice. FACS profile of marrow cells from a representative NOD/SCID mouse that 6 weeks earlier was transplanted with 2.5 x 105 4wCD34  (CD34 cells immunoselected after 4 weeks of expansion in presence of FL, SCF, and TPO). The BM of this primary mouse was injected into a secondary sublethally irradiated NOD/SCID mouse sacrificed 6 weeks after transplantation; the BM of this mouse was injected in a tertiary mouse also sacrificed 6 weeks after transplantation. Human CD45  cells represented 22% of the BM cells of the primary mouse, 7% of the secondary recipient that had received 25 x 106 unseparated BM cells of the primary mouse, and 2.5% of the tertiary mouse that received 30 x 106 total BM cells of the secondary recipient. FACS analyses of human CD41 expression in the BM of primary, secondary, and tertiary mice were performed on total BM: the percentages of CD41  cells were respectively: 1.3%, 0.6%, and 0.1%. The bottom panels represent the analysis of the CD41  population within the CD45  cell gate in each of the three recipients." _4 J; p9 @8 H8 t4 m/ r

6 a. b! w  f* M) ^: n& ]Platelet Production in NOD/SCID Mice' }! Y; n# Z" y" ?7 \
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The appearance of HuPlts in the mouse PB after CB injection was monitored from week 1 by FACS analyses. After total body irradiation murine platelets decreased from a mean of 1.45 ± 0.3 x 1012/l to a mean of 0.45 ± 0.1 x 1012/l at week 1 and increased to a mean of 0.8 ± 0.2 x 1012/l at week 3.
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& P& }5 {! |, VHuPlts were detected by staining PB cells with an anti-CD41 mAb against HuPlts surface GP IIb/IIIa. After transplantation of b34  cells, a maximum of 0.3% HuPlts was detected only at week 3 (Fig. 2). At week 4 HuPlt count was a mean of 4.5%; the percentage of the HuPlts was similar at 6–8 weeks after transplant in some transplanted mice. By contrast in the PB of mice injected with 2.5 x 105 4w34  cells, 0.5% of HuPlts were seen as early as week 1, even if the human CD41  cells in the murine BM were below the FACS detection limit (' i7 W# R3 ^! K: V! ]' V9 G- d

% X5 C( X% j+ ~( K9 i9 SFigure 2. Human platelet appearance. Kinetics of HuPlt appearance in the PB of NOD/SCID mice injected with 2.5 x 105 baseline CD34  cells, 2.5 x 105 CD34  cells immunoselected from 4-week expanded cultures and with all the CD34  progeny of 2.5 x 105 initial CD34  cells expanded for 4 weeks. Results show the mean ± SD of the percentage of HuPlts detected by FACS analysis in the murine PB at the indicated time points after transplantation (4 mice per experimental point, 3 separate experiments).& E/ b. H' E3 e) U  c

6 \' @9 V6 s9 a7 H6 l: ]9 rFigure 3. Flow cytometric analysis of human platelets in peripheral blood of NOD/SCID mice. A) PB samples (from a representative untransplanted mouse, a normal human donor, and a mouse injected 3 weeks previously with 2.5 x 105 4w34  cells) were labeled with a mAb against human CD41a. Analysis was performed within the platelet population gate based upon forward and side scatter. B) Flow cytometric analysis of HuPlts from a mouse transplanted 3 weeks previously with 2.5 x 105 4w34  cells before and after thrombin stimulation. On the y-axis PE-anti-human CD41a, on the x-axis FITC-anti-human CD62P. CD62P is expressed only on activated platelets. FACS analysis is carried out within the gate of HuPlts.
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HuPlt activation in response to in vitro challenge with thrombin was tested. Thrombin induces granule secretion resulting in CD62P expression on the platelet membrane. After thrombin stimulation, the expression of CD62P on human CD41  platelets was increased (Fig. 3B)., {  f( |- {! |' o2 d" g

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, I# M- ]4 z* s( E; CSupport for this work was provided by grants from the Associazione Italiana per la Ricerca sul Cancro (AIRC), Milan, Italy and from the Ministero dell’Universit角 e della Ricerca Scientifica e Tecnologica (MURST), Rome to W.P. and to M.A., and from CNR (Progetto Finalizzato Oncologia). The authors wish to thank Mrs. L. Ramini for invaluable secretarial assistance.
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作者: tempo    时间: 2016-9-10 22:54

不错啊! 一个字牛啊!  
作者: abc987    时间: 2016-10-15 17:18

干细胞与动物克隆
作者: 依旧随遇而安    时间: 2016-10-17 08:43

人气还要再提高  
作者: 命运的宠儿    时间: 2016-10-27 10:28

哈哈,看的人少,回一下  
作者: 甘泉    时间: 2016-12-12 16:27

我也来顶一下..  
作者: xuguofeng    时间: 2017-1-20 19:50

干细胞研究人员的天堂
作者: yukun    时间: 2017-2-21 18:23

挺好啊  
作者: ikiss    时间: 2017-2-21 23:25

今天的干细胞研究资料更新很多呀
作者: 加菲猫    时间: 2017-3-29 03:20

今天没事来逛逛  
作者: 狂奔的蜗牛    时间: 2017-3-30 15:00

严重支持!
作者: immail    时间: 2017-4-12 05:44

牛牛牛牛  
作者: dglove    时间: 2017-4-26 01:06

好贴坏贴,一眼就看出去  
作者: 甘泉    时间: 2017-5-5 17:34

挺好啊  
作者: 咖啡功夫猫    时间: 2017-5-14 07:27

我的妈呀,爱死你了  
作者: kaikai    时间: 2017-5-15 15:27

老大,我好崇拜你哟  
作者: 3344555    时间: 2017-5-16 17:51

干细胞研究还要面向临床
作者: na602    时间: 2017-5-31 13:34

细胞治疗行业  
作者: 修复者    时间: 2017-6-14 21:22

强人,佩服死了。呵呵,不错啊  
作者: 三好学生    时间: 2017-6-23 08:01

照你这么说真的有道理哦 呵呵 不进沙子馁~~~  
作者: 水木清华    时间: 2017-6-29 14:27

呵呵 大家好奇嘛 来观看下~~~~  
作者: bluesuns    时间: 2017-7-1 22:35

很好!很强大!  
作者: 糊涂小蜗牛    时间: 2017-7-7 07:14

@,@..是什么意思呀?  
作者: netlover    时间: 2017-7-16 07:07

照你这么说真的有道理哦 呵呵 不进沙子馁~~~  
作者: 剑啸寒    时间: 2017-7-29 02:31

顶顶更健康,越顶吃的越香。  
作者: 张佳    时间: 2017-9-13 10:35

我好想升级  
作者: 983abc    时间: 2017-9-21 04:18

不错,看看。  
作者: 考拉    时间: 2017-10-4 18:15

设置阅读啊  
作者: 苹果天堂    时间: 2017-10-15 14:28

(*^__^*) 嘻嘻……   
作者: 求索迷茫    时间: 2017-10-21 22:21

好贴子好多啊  
作者: laoli1999    时间: 2017-10-22 00:15

看或者不看,贴子就在这里,不急不忙  
作者: 丸子    时间: 2017-10-22 09:10

帮你项项吧  
作者: 小小C    时间: 2017-11-14 19:04

先看看怎么样!  
作者: dada    时间: 2017-12-29 10:27

进行溜达一下  
作者: marysyq    时间: 2018-1-16 04:25

越办越好~~~~~~~~~`  
作者: 旅美学者    时间: 2018-1-29 02:28

…没我说话的余地…飘走  
作者: 蚂蚁    时间: 2018-2-1 10:01

哦...............  
作者: 老农爱科学    时间: 2018-2-21 16:35

青春就像卫生纸。看着挺多的,用着用着就不够了。  
作者: 咕咚123    时间: 2018-2-25 22:43

楼主good  
作者: apple0    时间: 2018-3-3 11:01

干细胞库  
作者: 陈晴    时间: 2018-4-1 02:31

不对,就是碗是铁的,里边没饭你吃啥去?  
作者: 海小鱼    时间: 2018-4-3 02:01

今天再看下  
作者: abc987    时间: 2018-4-20 08:10

支持你加分  
作者: htc728    时间: 2018-4-23 06:41

加油站加油  
作者: abc987    时间: 2018-4-27 19:07

支持~~顶顶~~~  
作者: tuting    时间: 2018-5-3 21:54

端粒酶研究
作者: qibaobao    时间: 2018-5-6 01:07

其实回帖算是一种没德德,所以我快成圣人了  
作者: Whole    时间: 2018-5-17 20:11

呵呵,找个机会...  
作者: dmof    时间: 2018-6-6 10:10

干细胞之家 我永远支持
作者: 初夏洒脱    时间: 2018-6-7 18:01

干细胞与动物克隆
作者: Diary    时间: 2018-6-11 15:32

dddddddddddddd  
作者: 考拉    时间: 2018-6-21 07:54

说嘛1~~~想说什么就说什么嘛~~  
作者: 快乐小郎    时间: 2018-6-27 05:10

楼主good  
作者: 生科院    时间: 2018-7-11 00:10

努力,努力,再努力!!!!!!!!!!!  
作者: nosoho    时间: 2018-8-24 18:15

干细胞之家 我永远支持
作者: 蚂蚁    时间: 2018-8-31 23:18

今天无聊来逛逛  
作者: 三好学生    时间: 2018-9-16 14:35

今天没事来逛逛,看了一下,感觉相当的不错。  
作者: 桦子    时间: 2018-9-19 04:57

加油啊!!!!顶哦!!!!!  
作者: dypnr    时间: 2018-9-25 11:01

嘿...反了反了,,,,  
作者: tempo    时间: 2018-10-13 20:10

很好!很强大!  
作者: nauticus    时间: 2018-10-21 06:54

21世纪,什么最重要——我!  




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