间充质干细胞可能通过调控免疫细胞促进再生障碍性贫血小鼠骨髓的造血功能

目的:探讨间充质干细胞(MSCs)影响再生障碍性贫血小鼠造血功能的可能免疫机制。方法:30只小鼠分3组,分别为单纯照射组、再障模型组、MSCs治疗组,建立再生障碍性贫血小鼠模型。单纯照射组仅经5Gy[60Co]γ射线照射,再障模型组经5Gy[60Co]γ射线照射后输注DBA/2小鼠胸腺淋巴结细胞1×106cell/只,MSCs治疗组经5Gy[60Co]γ射线照射后输注DBA/2小鼠胸腺淋巴结细胞1×106cell/只,3d后输注人骨髓MSCs1×106cell/只。观察各组小鼠外周血象、骨髓及外周血CD4+细胞、CD8+细胞、CD4+/CD8+、NK细胞变化及与造血的关系。结果:经5Gy[60Co]γ射线照射后,单纯照射组、MSCs治疗组外周血象第7d开始下降,21d血象恢复正常。再障模型组外周血象第7d开始持续性下降,至21d血象仍未恢复。照射后7d,各组小鼠间外周血CD4+细胞、CD8+细胞、CD4+/CD8+无明显差异,但MSCs治疗组NK细胞低于单纯照射组和再障模型组(P0.05)。照射后14d3组CD4+细胞比例均明显下降,CD8+细胞则表现不同,再障模型组与MSCs治疗组CD8+细胞比例明显高于单纯照射组,至照射后21d,MSCs治疗组CD8+、NK细胞与单纯照射组相近、而模型组则明显高于单纯照射组和MSCs治疗组;MSCs治疗组小鼠股骨病理切片中脂肪细胞比例明显低于再障模型组,与单纯照射组结果一致。结论:MSCs输注可能通过调控免疫细胞影响再生障碍性贫血小鼠骨髓造血功能。     

骨髓间充质干细胞干预再生障碍性贫血患者树突状细胞的成熟分化CSCD

背景:骨髓间充质干细胞对再生障碍性贫血患者T细胞增殖的影响国内仅见少量报道,而骨髓间充质干细胞是否通过调节树突状细胞来影响再生障碍性贫血患者T细胞的增殖,国内未见报道,其机制值得深入研究。目的:观察骨髓间充质干细胞对再生障碍性贫血患者树突状细胞的免疫调节作用。方法:将培养第5天的再生障碍性贫血患者外周血单个核细胞来源的树突状细胞与第3代健康人骨髓间充质干细胞混合培养,加入脂多糖、肿瘤坏死因子促树突状细胞成熟,应用流式细胞仪检测骨髓间充质干细胞与未成熟、成熟树突状细胞共培养前后树突状细胞表面标志表达。结果与结论:未成熟的树突状细胞在脂多糖的刺激诱导下与骨髓间充质干细胞共培养前后,树突状细胞表面标志CD14,CD1a,CD83,CD80表达无变化(P>0.05);成熟树突状细胞与骨髓间充质干细胞共培养前后,树突状细胞表面标志CD14,CD1a,CD83,CD80表达降低(P<0.05)。结果说明骨髓间充质干细胞可抑制再生障碍性贫血患者单核细胞来源的树突状细胞的发育和成熟,进而发挥调节再生障碍性贫血患者的免疫作用。     

乙酰苯肼、X射线和环磷酰胺联合复制小鼠再生障碍性贫血模型

目的以乙酰苯肼、X射线、环磷酰胺联合应用的方法建立小鼠再生障碍性贫血动物模型。方法BALB/c小鼠,采用皮下注射乙酰苯肼100mg/kg,次日X射线2.0Gy照射后,于试验第5天环磷酰胺80 mg/kg腹腔注射,第15天重复以上步骤但不给予射线处理。观察试验小鼠的血象、骨髓象、造血细胞内的线粒体、造血干细胞集落的形成及肝脏、脾脏的病理变化。结果与正常对照组相比,再障模型组小鼠外周血象三系细胞均有显著降低:促红细胞生成素(EPO)含量升高;骨髓有核细胞数显著降低,造血干细胞集落的形成减低,肝脾出现再障的病理改变。结论本方法建立的再生障碍性贫血小鼠模型,简便,成功率高,外周血和骨髓的病理变化持续、稳定,符合再生障碍性贫血的临床表现。     

单倍体相合造血干细胞移植治疗儿童重型再生障碍性贫血

背景：目前治疗儿童再生障碍性贫血的主要方法为强化免疫抑制治疗或干细胞移植,后者由于供者来源少而受到限制,HLA单倍体相合的异基因造血干细胞在白血病治疗中常见应用,在再生障碍性贫血治疗中较少应用。目的：探讨单倍体相合的造血干细胞移植联合胎盘来源的间充质干细胞移植治疗重型儿童再生障碍性贫血的疗效。方法：患儿,女,7岁,确诊重型再生障碍性贫血1年半,2012-07-09接受HLA单倍体相合的异基因骨髓及外周血单个核细胞联合胎盘来源间充质干细胞移植,供者为母亲。预处理采用氟达拉滨联合环磷酰胺和抗胸腺细胞球蛋白方案。结果与结论：移植后+9 d中性粒细胞>0.5×10⁹ L^-1,+12 d完成造血重建,+100 d查STR提示植入完成。移植后+8个月停用免疫抑制药物,未发生急、慢性移植物抗宿主病。患儿随访18个月,无病生存。结果表明,HLA单倍体相合的造血干细胞联合胎盘来源间充质细胞移植治疗儿童重型再生障碍性贫血是一种安全有效、值得探索的方法。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

成人再生障碍性贫血患者骨髓间充质干细胞增殖分化潜能： 与健康人的比较

背景：骨髓间充质干细胞具有成脂和成骨分化潜能,再生障碍性贫血患者骨髓间充质干细胞可能存在成脂和成骨分化异常。 目的：观察再生障碍性贫血患者骨髓间充质干细胞增殖及分化潜能与健康人的差异。 方法：选择哈尔滨市第一医院血液病肿瘤研究所收治的再生障碍性贫血患者5例,另选5例健康成人作为对照组;采用全骨髓培养法分离骨髓间充质干细胞。 结果与结论：采用全骨髓培养法成功分离出骨髓间充质干细胞;与对照组相比,再生障碍性贫血组骨髓间充质干细胞的细胞形态和免疫表型无显著差异,皆表达CD73、CD90、CD105,不表达CD34、CD45和HLA-DR;再生障碍性贫血组骨髓间充质干细胞增殖能力显著低于对照组(P < 0.05),成脂肪细胞分化诱导率高于对照组(P < 0.05),PPARγ mRNA和FABP4 mRNA表达量均高于对照组(P < 0.05);而成骨细胞分化诱导率低于正常对照组(P < 0.05),ALP mRNA和BGLAP mRNA表达量分别低于对照组(P < 0.05)。提示再生障碍性贫血组骨髓间充质干细胞分化潜能存在成脂肪细胞和成骨细胞分化的失衡。     

第二次单倍体造血干细胞移植治疗首次移植失败再生障碍性贫血并发淋巴瘤1例

背景：急性重型再生障碍性贫血第一次异基因造血干细胞移植失败对患儿是严重致命的,若同时合并有继发性淋巴瘤等多种并发症,治疗就更为棘手,目前无成功方法可借鉴。 目的：探讨第二次HLA单倍体造血干细胞移植治疗首次移植失败且并发淋巴瘤的急性重型再生障碍性贫血患儿的有效性和安全性。 方法：回顾性分析1例急性重型再障患儿的二次造血干细胞移植的临床资料：患儿男,3岁,2011年11月25日行第一次非血缘异基因外周血干细胞移植(供受者HLA为8/10相合,血型主要不合),移植后粒细胞和血小板造血分别在11 d和14 d恢复,移植后30 d DNA移植植入鉴定和染色体检测均示移植成功植入,术后35 d出现皮肤Ⅰ度移植物抗宿主病,激素治疗后消失,术后54 d因出现自身免疫性溶血性贫血及纯红细胞再生障碍性贫血,给予大剂量丙种球蛋白冲击、激素及促红素等治疗好转,激素逐渐减量,EBV拷贝数逐渐升高,术后3个月患者出现发热、双侧颈部可触及数个肿大淋巴结,行B超引导下右侧颈部淋巴结穿刺活检,考虑移植后淋巴增殖性疾病,病理示：弥漫大B细胞淋巴瘤,治疗上减停免疫抑制剂,应用美罗华及CHOP方案化疗,淋巴结缩小,且EBV拷贝数下降,体温正常。移植术后5个月复查血象和骨髓象提示继发性植入失败,进而于2012年5月15日行第二次单倍体相合造血干细胞移植。供者为患儿的父亲,预处理方案为清髓性预处理方案：氟达拉滨+环磷酰胺+马利兰+米托蒽醌+抗CD52单克隆抗体。回输骨髓造血干细胞的同时输注脐带间充质干细胞。移植物抗宿主病预防：环孢素A+短程的甲氨喋呤+CD25单克隆抗体联合霉酚酸酯。回输的有核细胞分别为13.52×108/kg,CD34+细胞数为2.45×106/kg,无关供者脐带来源间充质干细胞的量为1×106/kg。随访时间为移植后24个月。 结果与结论：移植后中性粒细胞达到0.5×109 L-1,血小板计数≥20×109 L-1分别为14 d和30 d;二次移植后1个月DNA指纹检测说明造血干细胞移植成功植入。预处理后肿大淋巴结逐渐缩小,但术后2个月因淋巴结有增大趋势,停用免疫抑制剂并局部放疗后淋巴结缩小且稳定至今,PET无明显代谢异常区,移植后每半年定期随访,目前正常生活及上学。结果说明：单倍体造血干细胞联合脐带间充质干细胞共移植是安全、高效的治疗第一次移植失败重型再生障碍性贫血的方法,患儿可以耐受预处理毒性,造血恢复较快,移植物抗宿主病可控,值得进一步临床研究。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

氯甲基苯甲酰氨标记骨髓间充质干细胞在免疫介导骨髓衰竭小鼠模型体内的归巢

背景：再生障碍性贫血是T淋巴细胞免疫亢进破坏造血干祖细胞的一种异常免疫反应性疾病。骨髓间充质干细胞具有支持造血功能同时具有免疫调控作用。 目的：观察骨髓间充质干细胞移植骨髓衰竭模型小鼠体内的归巢情况。 方法：将BALB/c小鼠随机分成正常对照组、骨髓衰竭模型组和骨髓间充质干细胞移植组,于第6天将已标记氯甲基苯甲酰氨的BALB/c小鼠骨髓间充质干细胞经尾静脉注射途径移植给骨髓衰竭模型小鼠,采用流式细胞术和组织学荧光显微镜观察标记细胞在不同组织的动态分布。造模第14 天,观察各组小鼠的平均生存时间、外周血血象和骨髓形态学特征。 结果与结论：骨髓间充质干细胞经尾静脉输注后24 h在受体小鼠骨髓中可发现氯甲基苯甲酰氨阳性标记细胞,72 h时阳性标记细胞数量增多(P < 0.05)。骨髓间充质干细胞移植组小鼠濒死或处死前的白细胞、血红蛋白、血小板、骨髓单个核细胞数与模型组小鼠濒死时相比显著升高(P < 0.01)。骨髓衰竭模型组比骨髓间充质干细胞移植组平均生存时间短(P < 0.05)。结果证实,骨髓间充质干细胞输入骨髓衰竭模型体内能归巢至骨髓,促进造血恢复,减轻骨髓衰竭程度,显著延长生存时间。       

当归多糖干预线粒体凋亡改善骨髓衰竭的机制

文题释义： 再生障碍性贫血：①血象：呈全血细胞减少,少数病例早期可仅1系或2系细胞减少。贫血属正常细胞型,亦可呈轻度大红细胞。红细胞轻度大小不一,但无明显畸形及多染现象,一般无幼红细胞出现。网织红细胞绝对值和比例显著减少,中性粒细胞减少低于0.5×10⁹ L^-1,血小板低于20×10⁹ L^-1。②骨髓象：骨髓涂片大体观察油滴增多,骨髓小粒镜检空虚,非造血细胞和脂肪细胞增多,一般在50%以上。 线粒体凋亡：当线粒体膜电位下降,线粒体膜通透性增加,线粒体内促凋亡因子(例如Cyt C、AIF、SMAC/DIABLO、HTRA2/OMI、ENDOG)释放到胞质中。Cyt C与Apaf-1相互作用,在ATP和dATP的协助下形成凋亡复合体,凋亡复合体通过招募并激活Pro-Caspase9,形成Caspase9全酶。Caspase9全酶进一步激活效应Caspase3和Caspase7,启动Caspase级联反应,切割细胞中如α-tubulin、Actin、PARPA、Lamin等超过100种的底物,最终导致细胞凋亡。 背景：再生障碍性贫血的重要发病机制之一是造血干细胞衰竭,如何逆转骨髓衰竭是目前的热点问题。 目的：探讨当归多糖对骨髓衰竭小鼠线粒体功能异常的调控作用。 方法：将72只ICR小鼠随机分为对照组、模型组和治疗组,每组24只,后两组通过⁶⁰Co γ射线照射、腹腔注射环磷酰胺和灌胃氯霉素制备再生障碍性贫血模型,然后分别给予生理盐水或200 mg/kg当归多糖喂养2周,对照组不造模,正常喂养。造模后第1,7,14天进行外周血细胞、骨髓单个核细胞计数,并用透射电子显微镜观察骨髓的线粒体超微结构。采用免疫磁珠与流式结合的分选技术从骨髓单个核细胞中分离并纯化Lin^-Sca-1⁺c-Kit⁺(LSK)细胞,即造血干细胞,检测LSK细胞线粒体膜电位、活性氧水平以及Bcl-2、Bax、cleaved caspase-9、cleaved caspase-3、p38蛋白表达水平。 结果与结论：与对照组相比,模型组和治疗组血常规明显异常,骨髓单个核细胞计数明显下降,LSK细胞中线粒体数量减少,线粒体膜电位以及Bcl-2/Bax比值降低,活性氧水平以及cleaved caspase-9、cleaved caspase-3、p38蛋白表达水平升高(P < 0.05)。与模型组相比,治疗组上述异常得到明显改善(P < 0.05)。结果提示,当归多糖可能通过上调造血干细胞的线粒体膜电位、增加线粒体膜稳定性,逆转其异常凋亡水平,改善造血功能。 ORCID: 0000-0002-8771-5898(崔兴) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

非血缘外周血造血干细胞移植治疗重型再生障碍性贫血的有效性

文题释义：非血缘外周血造血干细胞移植：由于中华骨髓库的快速扩容,使得很多无HLA相合同胞供者的患者非血缘HLA配型成功,随着近期造血干细胞移植技术的不断完善,非血缘外周血造血干细胞移植治疗良性和恶性血液病的疗效已经取得与同胞相合造血干细胞移植相似的疗效。非血缘外周血造血干细胞移植治疗重型再生障碍性贫血：重型再生障碍性贫血如没有进行有效治疗,短期内死亡率高,强化免疫抑制治疗起效需要时间较长。虽然同胞相合造血干细胞移植是一线治疗方法,但多数患者无同胞相合供者,此类重型再生障碍性贫血患者非血缘外周血造血干细胞移植是有效可行的替代治疗方案。 背景：重型再生障碍性贫血患者获得同胞相合造血干细胞移植供者的概率低于30%,随着近期非血缘外周血造血干细胞移植技术的不断完善,其治疗良性和恶性血液病已经达到与同胞相合造血干细胞移植相似的疗效。目的：评价非血缘外周血造血干细胞移植治疗重型再生障碍性贫血的有效性和安全性。 方法：回顾性分析2014年3月至2019年9月期间接受非血缘外周血造血干细胞移植治疗的25例重型再生障碍性贫血(Ⅰ型和Ⅱ型)患者,均无同胞相合供者并且拒绝接受免疫抑制治疗。移植预处理方案为氟达拉滨+环磷酰胺+兔抗人胸腺细胞球蛋白抗体。移植物抗宿主病的预防方案为环孢素+吗替麦考酚酯+短程甲氨蝶呤。观察指标包括植入率及造血重建时间、移植物抗宿主病发生率、移植相关并发症发生率、5年预计总生存率、5年预计无病生存率。该临床研究的实施获得郑州大学第一附属医院伦理委员会批准,患者及亲属签署非血缘外周血造血干细胞移植相关知情同意书。结果与结论：①25例重型再生障碍性贫血患者中有3例移植后+28 d之内死亡,无法评价植入情况。剩余22例患者中有21例(95.4%)获得造血重建,植入成功;1例(4.6%)植入失败。中性粒细胞≥0.5×10⁹ L^-1和血小板≥20×10⁹ L^-1的中位时间分别为12 d(9-18 d)和13 d(10-32 d)。②植入成功的21例患者中,急性移植物抗宿主病发生率为28.6%(6/21),其中Ⅰ-Ⅱ度3例,Ⅲ-Ⅳ度3例。轻度慢性移植物抗宿主病患者仅有9.5%(2/21),无中度和重度慢性移植物抗宿主病发生。③中位随访396 d(15-1 886 d),18例(72.0%)存活,5年预计总生存率为71.1%,5年预计无病生存率为65.6%。7例(28.0%)死亡,其中3例(12.0%)患者死于感染,2例(8.0%)患者死于急性肠道移植物抗宿主病,1例(4.0%)患者死于颅内出血,1例(4.0%)患者死于多器官功能衰竭。④结果显示,对于无同胞相合供者的重型再生障碍性贫血患者,非血缘外周血造血干细胞移植是安全有效的治疗方法,是一项可行有益的替代治疗选择。 ORCID: 0000-0002-0880-309X(张素平) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

表达SDF-1/HOXB4融合基因的间充质干细胞联合脐血CD34~+干细胞共移植对辐射损伤小鼠的影响

目的观察表达SDF-1/HOXB4融合基因的间充质干细胞(mesenchymal stem cells,MSCs)联合脐血CD34+造血干细胞(hematopoietic stem cells,HSCs)共移植对辐射损伤小鼠的影响。方法表达SDF-1、HOXB4和SDF-1/HOXB4基因的3个腺病毒载体分别转染正常人骨髓MSCs,将其联合脐血CD34+细胞经尾静脉移植到辐射损伤的NOD/SCID小鼠体内(MSCs 8×105细胞/只,CD34+1×105细胞/只),分别为SDF-1/MSCs+CD34+组(SDF-1组)、HOXB4/MSCs+CD34+组(HOXB4组)、SDF1-HOXB4/MSCs+CD34+组(S-H组),另外3组为未转染MSCs+CD34+组(MSC-HSC组)、单纯CD34+组(HSC组)、单纯辐照组(IR组)。检测移植后各组小鼠存活率、外周血象恢复、骨髓病理变化及人源CD45+细胞植入率。结果 S-H组小鼠存活率高,且外周血WBC、HGB、PLT和骨髓造血功能恢复快。在移植后6周骨髓CD45+细胞植入率(47.43%±8.89%)较其余各组高。结论表达SDF-1/HOXB4融合基因的间充质干细胞(MSCs)联合脐血CD34+造血干细胞(HSCs)共移植能促进造血重建及植入,提高移植成功率。     

Transformation of polycythemia vera to chronic myelogenous leukemia

Transformation of polycythemia vera to chronic myelogenous leukemia is a rare event. We report 2 women with long-standing polycythemia vera who developed chronic myelogenous leukemia. Both patients had no BCR/ABL1 fusion at the time of polycythemia vera diagnosis but were positive for the fusion at chronic myelogenous leukemia onset. Most patients with polycythemia vera have JAK2(V617F) mutation. Analysis of an archival bone marrow aspirate sample from 1 patient showed a heterozygous mutation status. The blood and bone marrow samples from the other patient showed the presence of homozygous JAK2(V617F) mutation and BCR/ABL1 fusion. The possible pathogenesis of such an event is discussed in the light of current literature.     

JAK2-V617F-mutated myeloproliferative neoplasms reveal different allele burden within hematopoietic cell lineages: a microdissection study of bone marrow trephine biopsies

The JAK2-V617F mutation is prevalent in almost all patients with polycythemia vera (PV) and about half of the cases of essential thrombocythaemia (ET) and primary myelofibrosis (PMF). A different allele burden in these entities has long been noticed, but little is known about its distribution among the neoplastic hematopoietic cell lineages within the bone marrow. We conducted a microdissection study of JAK2-V617F-mutated myeloproliferative neoplasms (MPN); 10 cases each of ET, PV, and PMF, with separate analysis of the JAK2 mutation status in three hematopoietic cell lines (i.e., megakaryo-, granulo-, and erythropoiesis). Different numbers of cell lineages harboring the JAK2-V617F mutation were found, being the lowest in ET (17/30), higher in PV (24/30) and in PMF (22/30). The megakaryopoiesis was the most commonly mutated cell lineage (24/30 cases). By analyzing microdissectates we were able to demonstrate a different allele burden of the JAK2-V617F mutation in the megakaryo-, erythro-, and granulopoiesis within the bone marrow of a given case of MPN. We demonstrated differences in the number of mutated cell lineages. The different mutation status may contribute to the different phenotypes of ET, PV, and PMF.     

The role of Janus Kinase 2 V617F mutation in extramedullary hematopoiesis of the spleen in neoplastic myeloid disorders.

Extramedullary hematopoiesis (EMH) in the spleen is a characteristic feature of the chronic myeloproliferative disorders (CMPDs) and various other neoplastic or reactive myeloid conditions. However, the origin of these hematopoietic precursor cells and the molecular mechanisms underlying their development in the spleen is uncertain. The V617F mutation in the Janus Kinase 2 gene (JAK2(V617F)) was recently shown to be frequently and preferentially present in the peripheral blood and bone marrow cells of CMPD patients, and the resulting dysregulation of its downstream targets is important to CMPD pathogenesis. To determine the occurrence and potential role of JAK2(V617F) in splenic EMH cells, we studied splenectomy specimens from 47 patients with significant EMH. JAK2(V617F) was detected by real-time PCR melting curve analysis in 22 specimens, including 11/17 chronic idiopathic myelofibrosis, 7/7 polycythemia vera, 1/1 essential thrombocythemia, 1/3 CMPD unclassifiable, 1/5 chronic myelomonocytic leukemia, 0/5 chronic myelogenous leukemia, 1/3 myelodysplastic syndrome and 0/6 acute myeloblastic leukemia cases, whereas only the JAK2 wild-type allele was detected in the other 25. Nineteen of 20 cases with adequate bone marrow samples available for molecular examination demonstrated concordant JAK2 genotypes. Laser-capture microdissection was then used to enrich the EMH and non-EMH splenic cell fractions, confirming that the mutant alleles specifically originated from the EMH cells. Furthermore, megakaryocytes in the JAK2(V617F)-positive splenectomy specimens expressed higher levels of Bcl-xL, an antiapoptotic protein and downstream target of the JAK2/STAT5 pathway. Thus, JAK2(V617F) is frequently present in splenic EMH cells associated with CMPD, but it is rarely identified in splenic EMH cells associated with other myeloid disorders. Our results indicate that the precursor cells leading to extramedullary hematopoietic expansion in CMPD most likely originate from the transformed bone marrow clone. Also, dysregulation of downstream pathways such as Bcl-xL may be important to CMPD disease pathogenesis in the spleen.     

51Immune reactivity against Janus Kinase 2 mutation V617F in Polycythemia Vera Patients

Polycythemia Vera (PV) is a part of a group of Philadelphia Chromosome negative myeloproliferative diseases, in which an acquired Valine to Phenylalanine mutation in exon 12 of Janus Kinase II gene in a hematopoietic stem cell yields malignant clonal hyperproliferation leading to increased morbidity and mortality caused by trombosis, bone marrow fibrosis and severe Acute Myeloid Leukemia. The mutation is found in more that 90% of PV-patients and in ∼20% of chronic neutrophilic leukaemia and atypical chronic myeloid leukaemia. The JAK II V617F mutation represents an obvious target for cancer immune therapy. The overall purpose of this study is to investigate whether patients harbouring this mutation elicit a spontaneous T cell response against mutated JAK II Kinase and subsequently if reacting JAK II specific T cells are capable of killing target cells. Thus, we have predicted peptides at and surrounding the V617F mutation capable of binding to HLA molecules (included HLA molecules are HLA A2, A3 and A24 covering about 80% of Caucasian population). These peptides are used to study peripheral blood lymphocytes from PV patients for the presence of T cells capable of recognizing the predicted peptides in the context of the appropriate HLA molecule. The frequency and phenotype of reacting cells in patients expressing these HLA molecules will be analysed in order to examine a possible correlation between immune reactivity and disease progress. The ultimate goal is to prepare the platform for a clinical vaccination trial targeting the JAK II mutation.
Preliminary results: 60 polycythemia vera patients harbouring the mutation have been HLA-typed and their T cells tested in Elispots with HLA matched peptides. Two medium sized and a weak response have been detected. These preliminary results suggest the existence of an immune response against JAK II V617F.     

Janus kinase 2 V617F mutation is detectable in spleen of patients with chronic myeloproliferative diseases suggesting a malignant nature of splenic extramedullary hematopoiesis

Extramedullary hematopoiesis occurs in patients with a variety of hematologic diseases, and the spleen is a common site. Extramedullary hematopoiesis is very common in chronic myeloproliferative diseases and myeloproliferative/myelodysplastic diseases. The pathogenesis of extramedullary hematopoiesis is unknown. Using JAK2 V617F mutation as a molecular marker, we assessed paired spleen and bone marrow samples of 15 patients with various types of chronic myeloproliferative diseases and myeloproliferative/myelodysplastic diseases. The diagnosis was chronic idiopathic myelofibrosis (n=8), polycythemia vera (n=3), and chronic myelomonocytic leukemia (n=4). DNA was extracted from fixed, paraffin-embedded tissue and assessed for JAK2 V617F by real-time polymerase chain reaction assay followed by melting curve analysis. Concordant JAK2 mutation was detected in the paired samples in 7 patients. A discordant result with JAK2 V617F found in the spleen but not bone marrow was noted in 1 patient. These results indicate that extramedullary hematopoiesis in patients with chronic myeloproliferative diseases and myeloproliferative/myelodysplastic diseases is a clonal process and lend support to the theory that the cells of extramedullary hematopoiesis are carried from the bone marrow.     

人脐血间充质干细胞移植修复骨髓造血损伤

文题释义：间充质干细胞：是一种多功能干细胞,由胚胎发育早期的中胚层发展而来,存在于人的各种组织、器官中,如骨、软骨、脂肪、外周血和肌肉等。骨髓组织中的间充质干细胞最多,但其在骨髓细胞中的比例仍很低,只有0.01%-1.00%,且年龄越大其含量越少,骨髓中的间充质干细胞分化能力也呈下降趋势。与骨髓相比,脐血中所含的间充质干细胞更加原始,因而有更强的增殖、分化能力。相较于骨髓间充质干细胞而言,人脐血间充质干细胞具有来源广泛、取材方便、无伦理方面的限制,使得人脐血间充质干细胞成为再生医学中的另一重要来源。骨髓造血损伤动物模型：建立骨髓造血损伤动物模型的方法有很多,主要分为物理方法、化学方法及物理化学方法等。物理方法包括各种射线,如X射线等,化学方法主要指以环磷酰胺为代表的烷化剂类化疗药物,而物理化学方法也叫混合性方法,联合应用放射线和化疗药物建立动物模型。  摘要背景：大多数研究间充质干细胞体外培养对造血干细胞的增殖作用和骨髓间充质干细胞移植可降低辐照引起的造血细胞死亡,增加骨髓细胞存活,修复造血功能,而少有研究人脐血间充质干细胞移植对骨髓造血损伤的修复。目的：探讨人脐血间充质干细胞对骨髓造血微环境的修复情况。方法：选用雄性BALB/c小鼠随机分为3组,实验组和对照组小鼠进行总剂量为6 Gy的X射线全身照射,建立骨髓造血损伤模型,正常组为未经处理的正常小鼠。实验组小鼠照射当天经尾静脉输入CM-DiL标记的人脐血间充质干细胞5×10⁶/只(0.2 mL),对照组和正常组经尾静脉输入生理盐水0.2 mL,移植后第1,5,7,14,21天观察外周血血象恢复情况和骨髓造血微环境修复情况。结果与结论：①外周血常规：移植后第1,5,7天,实验组和对照组小鼠与正常组小鼠比较,白细胞、血小板、红细胞计数及血红蛋白浓度进行性下降,第7天下降最为明显,移植后第14天三系较前有所恢复,移植后第21天基本恢复正常,与实验组相比,对照组三系下降更为明显,移植后第14天实验组较对照组恢复快;②骨髓涂片情况：移植后第1,5,7,14天实验组及对照组小鼠骨髓出现造血功能抑制,以第7天最为明显,移植后第14天骨髓增生较前有所恢复,实验组优于对照组;移植后第21天实验组及对照组小鼠骨髓造血功能恢复,与正常组相比无差异;③骨髓病理切片情况：移植后第1,5,7,14天实验组及对照组小鼠骨髓出现造血功能抑制;移植后第14天实验组及对照组小鼠的骨髓造血功能较前开始恢复,实验组小鼠的骨髓增生情况优于对照组小鼠, 移植后第21天实验组及对照组小鼠骨髓增生情况与正常组比较无差异;④结果表明,人脐血间充质干细胞对骨髓造血功能恢复均有明显促进作用。ORCID: 0000-0002-7547-9664(高坤莉) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Genomic insult oriented mitochondrial instability and proliferative hindrance in the bone marrow of aplastic mice including stem/progenitor population

Aplastic anemia is the bone marrow failure condition characterized by the development of hypocellularity in both marrow and peripheral blood compartments. Anti-tumor chemotherapeutic agents often exert secondary effect on hematopoietic system leading to aplastic anemia by marrow failure. The precise mechanisms behind the marrow ablative effects of the drugs remain yet to be established. The present study holds a mechanistic approach to unveil the mystery. Aplastic anemia was generated in mice with the administration of busulfan and cyclophosphamide followed by the characterization of the disease with peripheral blood hemogram, histopathological and cytochemical examinations of bone marrow. To gain deep knowledge about the molecular mechanisms of the hematopoietic disruption, cytotoxicity assay, DNA damage measurement, apoptosis study, replicative senescence analysis, redox balance study, mitochondrial membrane potential change assessment, flowcytometric expressional analysis of p21, p53, ATM, Chk-2, Necdin, Gfi-1, c-myc, KU-80 and Sod-2 were done with marrow hematopoietic stem/ progenitor cells (HSPCs). Severe blood pancytopenia and marrow hypocellularity was found in aplastic mice. Proliferative hindrance and apoptosis of marrow cells were identified as the cause behind the hematopoietic catastrophe. The genotoxic effects of the drugs triggered chromatin damage and induced replicative senescence in aplastic HSPCs by upregulating p21 in a p53 independent manner. Moreover, accumulation of genomic insults also caused apoptotic elimination of marrow cells due to disruption of mitochondrial membrane potential by generating redox imbalance. The study established the underlying mechanisms behind hematopoietic disruption during drug induced marrow aplasia. Outcome of the study may be helpful in successful designing of therapeutic strategies for the disease concerned.