同种异基因造血干细胞移植急性移植物抗宿主病小鼠模型的制作

目的 制作同种异基因造血干细胞移植急性移植物抗宿主病(GVHD)小鼠模型.方法 以C57BL/6( H-2b)小鼠为供者,Balb/c( H-2d)小鼠为受者,进行同种异基因骨髓移植.设立全身照射(TBI)对照组(4只)、GVHD组(10只)、单纯骨髓移植组(10只)及正常对照组(4只).TBI对照组仅进行致死性TBI,TBI后不进行骨髓移植;GVHD组于TBI前5d开始饮用含320 mg/L庆大霉素和250 mg/L红霉素的饮用水,移植当天以60Co γ射线行一次性TBI,总剂量8.0Gy,TBI后5h内每只小鼠经尾静脉输注C57BL/6小鼠骨髓细胞2×106个+脾细胞1×107个;单纯骨髓移植组预处理与GVHD组相同,每只小鼠经尾静脉输注C57BL/6小鼠骨髓细胞2×106个.移植后观察小鼠的精神状态、活动能力、体位改变、皮毛、体重和大便等,记录每只小鼠的存活时间,计算存活率,并绘制生存曲线.濒死小鼠的皮肤、肝脏、小肠和骨髓行病理检查.结果 TBI对照组小鼠的存活时间为(9.0±0.7)d,GVHD组为(32.0±3.2)d,单纯骨髓移植组为(17.5±1.6)d,3组间两两比较,存活时间的差异均有统计学意义(P＜0.01).TBI对照组病理检查显示造血功能衰竭.GVHD组于移植后第10～13天出现急性GVHD表现,其皮肤、肝脏和小肠组织的病理表现均符合Ⅰ～Ⅱ度急性GVHD改变,单纯骨髓移植组也于移植后第10～13天出现GVHD表现,但其GVHD表现和组织学改变明显轻于GVHD组,仅为0～Ⅰ度GVHD.结论 Balb/c小鼠经致死性TBI后移植同种异基因小鼠骨髓细胞+脾细胞可成功制作稳定的急性GVHD模型.     

骨髓间充质干细胞的输注时机对小鼠骨髓移植后急性移植物抗宿主病的影响

目的 探讨骨髓间充质干细胞(MSCs)输注时机对异基因骨髓移植(allo-BMT)后急性移植物抗宿主病(aGVHD)的影响及其机制.方法 以Babl/c小鼠为供者,于无菌条件下获取其骨髓,制成MSCs悬液及骨髓细胞悬液.C57BL/6小鼠为受者,经电子直线加速器行全身照射后,分为5组进行allo-BMT.骨髓移植组受者经尾静脉输注骨髓细胞悬液和RPMI 1640培养液各0.2 ml;联合移植组受者经尾静脉输注骨髓细胞悬液和MSCs悬液各0.2 ml;延迟输注Ⅰ组受者经尾静脉输注骨髓细胞悬液0.2 ml,3 d后再输注MSCs悬液0.2 ml;延迟输注Ⅱ组受者经尾静脉输注骨髓细胞悬液0.2 ml,7 d后再输注MSCs悬液0.2 ml;对照组受者经尾静脉输注RPMI 1640培养液0.4 ml.记录受者存活时间及aGVHD的发生情况,检测外周血白细胞、CD4+ 和CD8+淋巴细胞数,测定血清γ干扰素(IFN-γ)和白细胞介素4(IL-4)水平,观察死亡小鼠的肝、脾、小肠及皮肤等组织病理学变化.结果 对照组受者均于移植后14 d内死亡.骨髓移植组于移植14 d以后出现aGVHD的表现,且均于23 d内死亡.联合移植组aGVHD的发生率为30%,延迟输注Ⅰ组aGVHD的发生率为60%,两组受者的存活时间均长于骨髓移植组.延迟输注Ⅱ组与骨髓移植组间aCVHD发生率和死亡时间的差异无统计学意义.受者的白细胞数均于全身照射后3 d降至最低,各移植组白细胞数皆于移植后回升,但骨髓移植组和延迟输注Ⅱ组的白细胞数未能恢复至正常水平,而联合移植组和延迟输注Ⅰ组的白细胞数均于移植后28 d恢复正常.输入MSCs者,CD4+淋巴细胞数量明显升高,而CD8+淋巴细胞数量下降,以联合移植组最为明显.联合移植组的IFN-γ水平明显低于骨髓移植组,而IL-4水平高于骨髓移植组.各组发生aGVHD的小鼠的肝、脾、小肠及皮肤病理改变基本一致.结论 MSCs与骨髓同时输注时aGVHD的发生率最低,受者的存活时间也最长,其机制可能与细胞因子水平有关.     

延迟并连续小鼠异基因骨髓移植减轻移植物抗宿主病的探讨

目的 探讨延迟并连续小鼠异基因骨髓移植减轻急性移植物抗宿主病(aGVHD)的作用及其机制.方法 选择BALB/c(H-2d)/b鼠为受者,C57BL/6(H-2b)小鼠为供者.受者接受60Coγ射线全身照射(TBI)后,建立骨髓移植模型.实验分为5组.对照组:TBI后4 h经受者尾静脉输注RPMI 1640液0.4 ml;经典移植组:TBI后4 h经受者尾静脉输注供者的骨髓细胞(BMC)和脾细胞(SC)各1×107个/0.2 ml;连续移植组:TBI后4 h、1 d、2 d和3 d分4次经受者尾静脉输注供者的BMC和SC,每次输注量各为2.5 × 106个/0.05 ml;延迟移植组:TBI后第4天经受者尾静脉输注供者的BMC和SC各1× 107个/0.2 ml;延迟并连续移植组:TBI后第4、5、6和7天分4次经受者尾静脉输注供者的BMC和SC,每次输注量各为2.5×106个/0.05 ml.移植后观察受者的临床表现、病理学改变及存活时间,采用酶联免疫吸附试验(ELISA)测定受者外周血中白细胞介素(IL)-2、IL-4、IL-10及γ干扰素(IFN-γ)的水平,应用流式细胞仪测定受者H-2b细胞、T淋巴细胞亚群及自然杀伤(NK)细胞的百分率.结果 对照组和经典移植组受者均在TBI后3周内因造血功能衰竭和/或aGVHD死亡;连续移植组和延迟移植组受者TBI后60 d存活率分别为30%和50%;延迟并连续移植组受者TBI后60 d的存活率为70%,高于其它4组(P＜0.05).延迟并连续移植组IL-4、IL-10的表达高于经典移植组(P＜0.05);IL-2和IFN-γ的表达低于经典移植组(P＜0.05).延迟并连续移植组TBI后20 d时外周血白细胞计数恢复正常,30 d时外周血T淋巴细胞亚群和NK细胞的表达恢复正常,60 d时H-2b细胞的百分率为(98.13±1.11)%.结论 延迟并连续小鼠异基因骨髓移植能减轻移植后的aGVHD.其作用机制主要是避开了TBI后炎症冈子表达的高峰期,下调了炎症因子和Th1类细胞因子的表达,促进了Th2类细胞因子的表达.     

利用脊柱骨来源骨髓细胞建立急性移植物抗宿主病模型

目的探讨利用脊柱骨来源骨髓细胞建立小鼠异基因造血干细胞移植(allogeneic hematopoietic stem cell transplantation,Allo-HSCT)急性移植物抗宿主病(aGVHD)模型的可行性。方法选择C57BL/6(H-2b)雄性小鼠为供体鼠,BALB/c(H-2d)雌性小鼠为受体鼠。制备供体鼠的脾细胞和脊柱骨来源骨髓细胞悬液。受体鼠采用药物加小剂量辐照的预处理方式,于移植前8d～移植前4d腹腔注射氟达拉滨(200mg/kg),接着移植前3d～移植前1d腹腔注射环磷酰胺(60mg/kg),最后在移植前进行全身照射(total-body irradiation,TBI),照射剂量为4Gy(戈瑞)。18只受体鼠经预处理后随机分为3组,每组6只:(1)骨髓移植组,只输入1×107个脊柱骨来源骨髓细胞;(2)aGVHD组,输注1×107个脊柱骨来源骨髓细胞和5×106个脾细胞,建立aGVHD模型;(3)空白对照组,不输入任何细胞。观察3组小鼠生存状态及存活率,取aGVHD组与骨髓移植组存活21d的受体鼠进行病理学检查,取aGVHD组移植后21～28d存活的小鼠的脾脏进行流式细胞术检测骨髓细胞嵌合度。结果骨髓移植组小鼠全部存活,可重建造血,单纯输注骨髓细胞不会诱发aGVHD。aGVHD组小鼠出现aGVHD表现,100%发生aGVHD相关死亡,中位生存期为18d;病理检查结果显示符合aGVHD病理表现,移植后21～28d存活的小鼠诊断为供受体混合嵌合状态,符合aGVHD诊断标准。结论用脊柱骨来源骨髓建立的aGVHD模型完全符合标准,且更加经济,适合大规模建模。     

输注鼠基因工程Treg细胞抑制小鼠异基因骨髓移植后移植物抗宿主病

目的 探讨输注慢病毒载体介导的鼠基因工程调节性T淋巴细胞(Treg细胞)对小鼠异基因骨髓移植后移植物抗宿主病(GVHD)的影响.方法 利用慢病毒载体介导,将鼠又状头螺旋转录因子(Foxp3)基因转导入Balb/c小鼠的CD4~+ CD25~-T淋巴细胞,即为基因工程Treg细胞.以Balb/c小鼠为供者,C57BL/6小鼠为受者,进行异基因骨髓移植,实验分4组进行:(1)工程Treg组经受鼠尾静脉输注供鼠骨髓细胞5×10~6个+脾细胞5×10~6个+基因工程Treg细胞5×10~6个;(2)移植对照组经受鼠尾静脉输注供鼠骨髓细胞5×10~6个+脾细胞5x10~6;(3)单纯照射组经受鼠尾静脉输注RPMI 1640培养液0.2ml;(4)空载体对照组经受鼠尾静脉输注供鼠骨髓细胞5×10~6个+脾细胞5×10~6个十空载体转导的CD4~+ CD25~-T 淋巴细胞5×10~6个.每天观察受鼠存活情况;记录GVHD的发生情况;各组均于小鼠濒死前取其肝脏、小肠、皮肤等组织,进行病理学观察;取长期存活(超过60d)的受鼠骨髓细胞,检测嵌合情况.结果 单纯照射组、移植对照组、工程Treg组和空载体对照组小鼠存活时间分别为(8.8±0.6)d、(36.7±2.5)d、(51.6±4.0)d和(34.1±2.3)d,工程Treg组小鼠存活时间明显长于其他各组,差异有统计学意义(P<0.05).移植对照组及空载体对照组小鼠肝脏、皮肤和小肠病理切片均存在GVHD病理改变,工程Treg组长期存活小鼠的肝脏、皮肤和小肠常规病理切片结构基本正常,未见GVHD病理表现,该组GVHD评分明显低于移植对照组及空载体对照组.结论 小鼠异基因骨髓移植时联合输注基因工程Treg细胞可有效减少GVHD的发生,减轻其严重程度.     

基因工程Treg细胞对小鼠异基因骨髓移植后GVHD和GVL效应的影响

目的 探讨输注慢病毒载体介导的小鼠基因工程调节性T淋巴细胞(Treg细胞)对小鼠异基因骨髓移植后移植物抗宿主病(GVHD)及移植物抗白血病(GVL)效应的影响.方法 利用慢病毒载体介导,将小鼠叉状头螺旋转录因子(Foxp3)基因转导入Balb/c小鼠的CD4+CD25-T淋巴细胞,即为基因工程Treg细胞.以Balb/c小鼠为供者.C57BL/6小鼠为受者,进行异基因骨髓移植,移植当天受者接受X线直线加速器全身照射.用随机数字表法将受者分为5组,每组10只.(1)单纯照射组:经受者尾静脉输注RPMI 1640培养液0.2 ml;(2)白血病对照组:经受者尾静脉输注供者骨髓细胞5×106个+C57BL/6小鼠T淋巴细胞白血病/淋巴瘤细胞株(EL4细胞)500个;(3)移植对照组:经受者尾静脉输注供者骨髓细胞5×106个+脾细胞5×106个+EL4细胞500个;(4)工程Treg组:经受者尾静脉输注供者骨髓细胞5×106个+脾细胞5×106个+EL4细胞500个+基因工程Treg细胞5×106个;(5)空载体对照组:经受者尾静脉输注供者骨髓细胞5×106个+脾细胞5×106个+EL4细胞500个+空载体转导的CD4+CD25-T淋巴细胞5×106个.每天观察受者存活情况;记录GVHD及白血病的发生情况;各组均于小鼠濒死前取其肝脏、小肠、皮肤、脾脏等组织,进行病理学观察;取长期存活(超过60 d)受者的骨髓细胞,检测嵌合情况.结果 单纯照射组、白血病对照组、移植对照组、工程Treg组和空载体对照组小鼠存活时间分别为(10.3±1.5)d、(20.7±1.9)d、(26.0±4.3)d、(49.0±17.7)d和(24.4±4.1)d,工程Treg组小鼠存活时间明显长于其他各组,差异有统计学意义(P＜0.05).白血病对照组小鼠肝、脾组织病理切片均存在白血病细胞浸润表现,移植对照组及空载体对照组小鼠肝脏、皮肤和小肠病理切片存在GVHD病理改变,而工程Treg组长期存活小鼠各组织病理切片结构基本正常,未见GVHD及白血病细胞浸润病理表现,该组GVHD评分明显低于移植对照组及空载体对照组.结论 小鼠异基因骨髓移植时联合输注基因工程Treg细胞可有效减少GVHD的发生并保留GVL效应.     

输注Wnt3a基因修饰的骨髓间充质干细胞减轻小鼠急性移植物抗宿主病

目的 探讨联合输注经Wnt3a基因修饰的MSC减轻小鼠异基因骨髓移植(allo-BMT)后急性移植物抗宿主病(aGVHD)的作用及其可能机制.方法 以C57BL/6小鼠为供鼠,以Balb/c小鼠为受鼠,建立小鼠allo BMT模型.采用随机数字表法将受鼠分为4组:(1)移植对照组(A组):经受鼠尾静脉仅输注供鼠骨髓细胞5×106个;(2) aGVHD组(B组):经受鼠尾静脉输注供鼠脾细胞5×106个及骨髓细胞5×106个;(3)aGVHD+空载体组(C组):经受鼠尾静脉输注供鼠脾细胞5×106个、骨髓细胞5×106个及转染了空载体pAd-GFP的MSC 1×106个;(4)实验组(D组):经受鼠尾静脉输注供鼠脾细胞5×106个、骨髓细胞5×106个及经Wnt3a基因修饰的MSC1×106个.移植后监测各组受鼠的一般表现和存活情况,观察aGVHD的发生情况,检测受鼠脾脏中供者来源的T淋巴细胞数量变化及白细胞介素2(IL-2)和γ干扰素(IFN-γ)水平.结果 A组受鼠的存活时间均超过60d;B、C、D组受鼠的存活时间分别为(19.1±6.19)d、(32.6±19.6)d和(47.2±15.6)d,D组受鼠的存活时间较B组和C组明显延长(P＜0.05).移植后,B、C、D组受鼠的aGVHD评分分别为(8.0±0.41)分、(6.7±0.29)分和(4.0±1.0)分,D组受鼠的aGVHD评分较B组和C组明显降低(P＜0.05),且病理分级明显减轻.移植后3和5d时D组受鼠脾脏中供者T淋巴细胞的数量和增殖速度均较B组和C组明显降低(P＜0.05),并且移植后7、14、21、28 d时D组受鼠血清IL-2和IFN-γ水平均较B组和C组明显减少(P＜0.05).术后60d时,长期存活受鼠的骨髓细胞中H-2Kb细胞的嵌合率均在95％～100％.结论 联合输注经Wnt3a基因修饰的MSC可更有效的减轻小鼠allo-BMT后的aGVHD,这可能与Wnt3a的过表达激活了MSC的Wnt/β-catenin信号通路,从而抑制供者T淋巴细胞的早期激活和扩增及抑制IL-2和IFN-γ的表达有关.     

粒细胞集落刺激因子减轻小鼠混合骨髓移植后移植物抗宿主病的实验研究

目的探讨同基因骨髓混合一定比例粒细胞集落刺激因子(G-CSF)动员的异基因骨髓移植能否减轻急性移植物抗宿主病(aGVHD).方法将BALB/c与BCF1(BALB/c×C57BL/6)小鼠或与G-CSF动员BCF1小鼠脾细胞按一定比例混合,腹腔注入BALB/c幼鼠,制备新生小鼠GVHD模型,结果以脾指数表示.成年雌性BALB/c小鼠接受60Co全身照射8.5Gy后进行移植,移植物为BALB/c与雄性BCF1或与G-CSF动员BCF.小鼠骨髓细胞按一定比例的混合,移植细胞总数60×105个/只.观察移植小鼠aGVHD典型症状、病理表现及存活率.ELISA法测定细胞因子含量,流式细胞术分析T细胞亚群变化.结果(1)注射BALB/c与BCF1小鼠脾细胞混合比例为21、11及异基因BCF1小鼠脾细胞的新生小鼠均发生GVHD;但G-CSF动员与否,GVHD发生程度差异有统计学意义.(2)21及11混合骨髓移植(MBMT)组小鼠有中到重度GVHD表现;经G-CSF动员的MBMT组小鼠8周存活率较未动员组明显提高(P＜0.05).(3)G-CSF动员供鼠后L3T4+细胞下降显著,L3T4+/Lyt2+比值明显低于未动员组(P＜0.01).(4)G-CSF动员供鼠后混合淋巴细胞反应(MLR)细胞培养上清中,IL-2、IFN-γ水平降低,IL-4水平升高.结论同基因骨髓混合一定量H-2半相合异基因骨髓移植可减轻GVHD的发生;G-CSF动员供鼠可进一步减轻MBMT后GVHD的发生.其机理可能与IL-2、IFN-γ下降、IL-4升高有关.     

HSV-sr39TK-GCv/ACV系统抑制小鼠异基因骨髓移植后移植物抗宿主病

目的 研究突变型单纯疱疹病毒胸苷激酶一更昔洛韦/阿昔洛韦(HSV-sr39TK-GCV/ACV)系统对小鼠异基因骨髓移植后移植物抗宿主病(GVHD)的影响.方法 采用改良的磷酸钙沉淀法,以携带HSv-sr39TK基因的慢病毒感染C57BL/6小鼠的脾淋巴细胞.制得sr39TK+T淋巴细胞.以C57BL/6小鼠为供者,Balb/c小鼠为受者进行骨髓移植,受者移植前接受60>Coγ射线照射.实验分6组进行:(1)GCV组共30只小鼠,均于骨髓移植的同时输注sr39TK+T淋巴细胞.其中10只于骨髓移植当天至第6天腹腔注射GCV 0.5 mg/d,10只于骨髓移植后第7～13天腹腔注射GCV0.5 mg/d,10只于骨髓移植后第12～18天腹腔注射GCV 0.5 nag/d;(2)ACV组共30只小鼠,骨髓移植与sr9TK+T淋巴细胞输注同GCV组,其中10只于骨髓移植当天至第6天腹腔注射ACV 0.5mg/d,10只于骨髓移植后第7～13天腹腔注射ACV 0.5 mg/d,10只于骨髓移植后第12～18天腹腔注射ACV 0.5 mg/d;(3)移植对照组仅行骨髓移植;(4)脾细胞对照组行骨髓移植和脾淋巴细胞输注;(5)GCV对照组在脾细胞对照组的基础上于骨髓移植后第7～13天腹腔注射GCV 0.5 mg/d.(6)sr39TK对照组行骨髓移植和sr9TK+T淋巴细胞输注.观察各组受者的存活时间、GVHD的发生情况及程度.结果 GCV对照组、sr9TK对照组、睥细胞对照组和移植对照组小鼠均于骨髓移植后19 d内死亡.GCV组移植当天用药者、第7天用药者和第12天用药者的存活时间分别为(36.70±5.20)d、(40.30±4.69)d和(27.10±4.85)d.ACV组移植当天用药者、第7天用药者和第12天用药者的存活时间分别为(36.50±5.26)d、(46.20±3.61)d和(30.90±5.21)d.GCV组和ACV组受者的存活时间均长于4个对照组(P<0.01),GCV组和ACV组中第7天用药者的存活时间和5(1 d存活率优于其它各时间用药者,差异有统计学意义(P<0.05),而ACV组第7天用药者又明显优于GCV组第7天用药者(P<0.05).4个对照组小鼠移植后10～12 d均开始出现Ⅲ～Ⅳ级GVHD.GCV组和ACV组死亡小鼠可见Ⅱ～Ⅳ级GVHD.而该两组中长期存活受者仅有Ⅰ～Ⅱ级GVHD.结论 HSV-sr9TK-GCV/ACV系统对小鼠异基因骨髓移植后的GVHD有一定的抑制作用;ACV的效果优于GCV;移植后7 d时应用ACV的效果较佳.     

硼替佐米对小鼠急性移植物抗宿主病的抑制作用

目的 探讨硼替佐米对小鼠急性移植物抗宿主病(aGVHD)的抑制作用及其可能机制.方法 以C57BL/6小鼠为供鼠,获取骨髓细胞及脾细胞.以Balb/c小鼠为受鼠,共分为5组:空白对照组(n=17)小鼠不予任何处理;单纯照射组(n=17)小鼠仅接受7.0 Gy X射线全身照射(TBI);药物对照组(n=17)小鼠也接受TBI,并且由尾静脉注射硼替佐米;aGVHD组(n=8)小鼠TBI后注射供鼠骨髓细胞及脾细胞;实验组(n=8)小鼠TBI后输注供鼠骨髓细胞及脾细胞,并予以硼替佐米.观察各组小鼠aGVHD的发生情况、存活时间及嵌合状态,蛋白印迹法测定空白对照组、单纯照射组和药物对照组小鼠肝脏及小肠组织细胞核中核因子κB(NF-κB)p65的表达.结果 aGVHD组和实验组的临床aGVHD评分分别为7.37±0.32和5.85±0.40,实验组明显低于aGVHD组(P＜0.05).aGVHD组受鼠肝脏、小肠及皮肤组织为Thomas GVHD病理分级Ⅲ～Ⅳ级改变.实验组受鼠肝脏、小肠及皮肤组织为Ⅰ～Ⅲ级GVHD改变,较aGVHD组有所减轻.实验组存活时间长于aGVHD组(P＜0.05).aGVHD组和实验组小鼠移植后12 d时外周血细胞中H-2Kb分子阳性细胞的百分率均＞90%.药物对照组肝脏及小肠组织细胞核内NF-κB p65表达均高于单纯照射组(P＜0.05).结论 硼替佐米可能通过在一定程度上抑制照射预处理损伤所致肝脏及小肠组织中NF-κB的激活起到减轻aGVHD的作用.

Abstract：

Objective To observe the effect of bortezomib on acute graft-versus-host disease (aGVHD) in an aGVHD model of mice and investigate the related mechanism. Methods Male C57BL/6( H-2Kb)mice were used as donors and female Balb/c (H-2Kd) mice used as recipients. Balb/c mice received total body irradiation (TBI) by 7.0 Gy X-radiation, and randomly divided into five groups. normal (group A), TBI (group B), TBI + bortezomib (group C), TBI + bone marrow cells (BMC) + spleen cells (SC) (group D) and TBI + bortezomib + BMC + SC (group E). The physical signs and the pathological damage of aGVHD, mean survival time, and chimerism were observed in recipients. The NF-κB p65 levels in nuclei of the liver and small intestine tissues of groups A,B and C were analyzed by Western blot. Results ( 1 ) The clinical aGVHD score in group D was (7.37±0. 32), significantly higher than in group E (5.85 ± 0.40) (P＜0. 05). Histopathology of the gut, liver and skin illuminated that the Ⅲ-Ⅳ degree GVHD occurred in group D. The occurrence of aGVHD in group E was later than in group D. The symptoms and the pathological damage of aGVHD in group E were milder than in group D. The average survival time in group E was significantly longer than that in group D (P＜0.05). The percentage of donor-derived cells in recipient mice was above 90% at day 12 after transplantation; (2) NF-κB p65 levels in nuclei of the liver and small intestine tissues in group B was significantly higher than in group C on the day 1,3 and 5 (P＜0. 05). Conclusion Bortezomib can inhibit the activation and expression of NF-κB,which may be the underlying mechanism for it to relieve aGVHD.     

吗替麦考酚酯抑制小鼠TH17细胞的分化和增殖

目的 通过观察吗替麦考酚酯(MMF)对小鼠辅助性T淋巴细胞17(TH 17细胞)分化和增殖的影响,探讨MMF的免疫抑制作用及其机制.方法 采用随机数字表法将小鼠分为MMF组与对照组,每组8只.MMF组小鼠每天给予MMF 40 mg·kg-1·d-1灌胃,对照组小鼠每天给予等体积生理盐水灌胃.3周后取小鼠外周血和脾脏,采用流式细胞术检测小鼠外周血和脾细胞中TH17细胞和CD4+CD25+调节性T淋巴细胞(Treg细胞)的比例,并计算出TH 17细胞与Treg细胞的比值;采用酶联免疫吸附试验法分别检测两组小鼠血清中白细胞介素(IL)-17和IL-23的浓度.结果 MMF组外周血和脾细胞中TH17细胞比例分别为(1.95±0.08)％和(2.42±0.06)％,对照组分别为(3.19±0.07)％和(4.21±0.25)％,两组比较,差异均有统计学意义(P＜0.05).MMF组外周血和脾细胞中TH 17细胞与Treg细胞的比值均显著低于对照组(P＜0.05).MMF组小鼠血清IL-17水平明显低于对照组(P＜0.05),而血清IL-23水平高于对照组(P＜0.05).结论 MMF能够明显抑制小鼠体内TH17细胞的分化与增殖,降低TH 17细胞与Treg细胞的比值,减少IL-17的分泌,有利于诱导免疫耐受.     

TH17 cells are critical for skin-specific pathological injury in acute graft-versus-host disease

Interleukin-17 (IL-17), which is important for host defens, has been implicated in autoimmune and chronic inflammatory diseases. As knockout mice lack IL-17 expression in δγT, NKT-like cells, studies investigating the association between TH17 cells and cutaneous graft-versus-host disease (GVHD) in animal models have reported conflicting results. To determine the role of TH17 cells in cutaneous GVHD, we developed an acute GVHD model using C57BL/6(H-2^b) donors to BABL/c (H-2^d) recipients. Blood samples and skin were examined for inflammation and infiltrating cells using histology and fluorescence-activated cell sorter (FACS) on days 6 and 15 after bone marrow transplantation. We found donor T cells to mediate severe cutaneous inflammation, which was ameliorater by administration of halofuginone (HF) to the recipients. Mechanistically, we demonstrate the severe tissue damage during this disorder to be associated with the production of IL-17 and the expansion of IL-17-producing CD4⁺ cells. Specific inhibition of TH17 differentiation and function by HF reduced disease severity. Thus, TH17 cells are sufficient to induce acute cutaneous GVHD.     

Immunosuppressive activity of the Chinese medicinal plant Tripterygium wilfordii. III. Suppression of graft-versus-host disease in murine allogeneic bone marrow transplantation by the PG27 extract

BACKGROUND: PG27 is an active fraction purified from an extract of a Chinese medicinal plant, Tripterygium wilfordii Hook f. We tested PG27 in murine allogeneic bone marrow transplantation (BMT) and investigated the mechanism of graft-versus-host disease (GVHD) suppression. METHODS: Recipients in the C57BL/6 --> BDF1 murine BMT model received oral or intraperitoneal PG27. RESULTS: Fourteen days of PG27 given orally or intraperitoneally prevented GVHD development and produced extended disease-free survival (more than 300 days) for many animals. PG490-88, a semisynthetic derivative of PG490 (triptolide, present in PG27), was also efficacious. PG27 reduced day 7 splenic allospecific cytotoxic T lymphocyte levels by more than 99% compared with vehicle-treated mice. Compared with normals, spleens from control allogeneic BMT mice displayed significantly reduced mononuclear cell content, an increased percentage of CD8+ cells, fewer CD4+ cells, and more activated ([interleukin-2 receptor+], IL-2R+) CD8+ T cells. PG27 increased mononuclear cell recovery, and significantly reduced the day-14 percentages of CD3+ and IL-2R+ cells in allogeneic BMT mice, producing results similar to those for syngeneic BMT mice. PG27 significantly increased concanavalin A-stimulated in vitro IL-4 production by day-14 splenocytes, with a 7- to 8-fold higher level than that produced by control cells. CONCLUSIONS: PG27 treatment for only 14 days prevented GVHD induction and development and produced long-term survival. PG27 largely normalized splenic T lymphocyte subsets, reduced allospecific cytotoxic T lymphocyte activity, and increased IL-4 production capability. PG27 may suppress GVHD by the induction of anergy and a deviation away from a proinflammatory phenotype, which could be reflected in the increased potential for IL-4 production.     

Bone marrow transplant conditioning intensified with liposomal clodronate to eliminate residual host antigen presenting cells fails to ameliorate GVHD and increases PERI-BMT mortality

BACKGROUND: Graft versus host disease (GVHD) mediated by allogeneic donor T cells may be initiated and/or exacerbated by residual host antigen presenting cells (APC) which survive the transplant conditioning regimen. We examined whether the depletion of hepatic and splenic APC could reduce the severity of hepatic GVHD after bone marrow transplantation (BMT). METHODS: Recipient mice were depleted for hepatic and splenic phagocytic APCs by i.v. injection of clodronate- (dichloromethylene diphosphonate) containing liposomes before fully allogeneic or MHC-matched, minor Ag-mismatched BMT. Severity of hepatic GVHD was scored on histological sections 2, 3, 4, or 9 weeks after BMT. RESULTS: No differences in the severity of GVHD were observed between APC-depleted mice and control mice. APC-depleted mice had increased peritransplant mortality due to sepsis. Bacterial clearance assays showed that APC-depleted mice were unable to efficiently clear bacteria, although nondepleted, transplanted mice were able to clear bacteria as quickly as naive control mice. CONCLUSIONS: Residual host phagocytic APC do not appear to play a role in the induction of GVHD after BMT. They are, however, essential for prevention of sepsis in the transplant host.     

A decrease in graft-vs.-host disease without loss of graft-vs.-leukemia reactivity after MHC-matched bone marrow transplantation by selective depletion of donor NK cells in vivo.

It is thought that natural killer cells may play a role in graft-vs.-host reactions after allogeneic bone marrow transplantation, but the use of NK cell-specific reagents has been limited. In this report, an NK allele-specific monoclonal antibody, anti-NK 1.1, was used to study the impact of in vivo donor NK cell depletion on GVH disease, graft-vs.-leukemia (GVL) reactivity and donor T cell chimerism after allogeneic murine BMT. AKR/J (H-2k) recipient mice were preconditioned with suboptimal irradiation (9 Gy = LD50) and transplanted with major histocompatibility complex-matched B10.BR (H-2k) BM cells with or without added spleen cells as a source of T cells. The addition of increasing numbers of spleen cells to the BM inoculum produced GVHD of varying intensities. The beneficial effect of NK depletion on GVHD was dependent on the intensity of the GVH reaction. Donor NK cell depletion had no effect on the survival of mice with severe GVHD after MHC-matched BMT (B10.BR into AKR) or after MHC-mismatched BMT (B10.BR into DBA/2; H-2k into H-2d). However, donor NK depletion increased survival of AKR hosts given sufficient B10.BR splenic T cells to induce mild-to-moderate GVHD. Ex vivo depletion of donor CD8+ T cells also reduced GVH-associated mortality, but the use of both CD8 and NK depletion offered no improvement over either alone, suggesting an interaction between CD8+ and NK 1.1+ cells. In contrast to CD8 depletion, donor NK depletion did not compromise the rapid and complete establishment of donor T cell chimerism nor the ability of chimeras to mount an effective GVL reaction. Thus, elimination of donor NK cells provides an alternate strategy for reducing GVHD without loss of GVL reactivity following MHC-matched allogeneic BMT.     

小鼠造血干细胞移植后移植物抗宿主病与内皮细胞损伤的关系

目的 探讨异基因造血干细胞移植后移植物抗宿主病(GVHD)与内皮细胞损伤的关系.方法 以C57BL/6小鼠为供者、Balb/c小鼠为受者,分4组进行异基因造血干细胞移植,每组受者15只:对照组(仅输入磷酸盐缓冲液)、单纯骨髓移植组(仅输入骨髓单个核细胞)、GVHD组(输入骨髓单个核细胞和脾细胞)、GVHD减轻组(在GVHD组基础上加用环孢素A).分别于移植后不同时间观察受者的表现,检测外周血中内皮细胞及组织病理学变化.结果 术后第5天,各组受者均无典型的GVHD表现及组织病理学改变;术后第9天,GVHD组受者出现明显的GVHD的表现及病理学改变,并于15 d内全部死亡.术后第5天,单纯移植组、GVHD组和GVHD减轻组受者的外周血中内皮细胞数分别为(11.51±7.40)、(7.34±1.26)和(7.36±0.16)个/μl,三组间差异均无统计学意义(P＞0.05);术后第9天,内皮细胞数分别为(10.49±5.61)、(153.64±35.35)及(47.82±4.69)个/μl,三组间差异均有统计学意义(P＜0.05).术后第5天,单纯移植组、GVHD组、GVHD减轻组受者GVHD靶器官组织病理学评分分别为3.33±0.58、4.33±1.53及4.0±1.73,三组间差异均无统计学意义(P＞0.05);术后第9天,评分分别为3.33±1.15、10.0及4.33±0.58,三组间差异均有统计学意义(P＜0.05);术后第14天,评分分别为2.33±1.25、10.33±2.58和3.33±1.15,三组间差异均有统计学意义(P＜0.05).结论 GVHD的发生再次引起内皮的损伤,同时损伤的内皮加重了GVHD.

Abstract：

Objective To study the relationship between graft-versus-host disease (GVHD) and endothelium injury following hematopoietic stem cells transplantation in mice. Methods C57BL/6 mice as donors and Balb/c mice as recipients were randomly divided into 4 groups: control group, bone marrow transplantation group, GVHD group, GVHD mitigation group. The clinical manifestations,circulating endothelial cells and tissue pathological changes were observed at different time points after transplantation. Results No manifestations of GVHD were found in each group at the day 5, while those were found in GVHD group at the day 9 and all died within 15 days. The counts of endothelial cells in peripheral blood showed no significant difference at the day 5 between GVHD group (7. 34 ±1.26 cells/μl) and bone marrow transplantation group (11.51 ± 7. 40 cells/μl) or GVHD mitigation group (7. 36 ± 0. 16 cells/μl), while among three groups there was statistically significant difference at the day 9 (GVHD group: 153. 64 ± 35. 35 cells/μl vs bone marrow transplantation group: 10. 49 ±5. 61 cells/μl and GVHD mitigation group: 47. 82 ± 4. 69 cells/μl). The scores of pathological aGVHD had no significant difference at the day 5 between GVHD group (4. 33± 1. 53) and bone marrow transplantation group (3. 33 ± 0. 58) or GVHD mitigation group (4. 00 ± 1.73), while among three groups there was statistically significant difference at the day 9 (GVHD group: 10. 0 vs bone marrow transplantation group: 3. 33 ± 1.15 or GVHD mitigation group: 4. 33 ± 0. 58) and at the day 14 (GVHD group: 10. 33 ± 2. 58 vs bone marrow transplantation group: 2. 33 ± 1.25 or GVHD mitigation group 3. 33 ± 1.15). Conclusion Occurrence of GVHD causes endothelial damage again and injured endothelium worsens the GVHD.     

Interleukin-17-producing cells increase among CD4+ lymphocytes before overt manifestation of acute graft-versus-host disease

Interleukin-17A is a hallmark of a subset of CD4+ lymphocytes called T(H)17. Allogeneic hematopoietic stem cell transplantation (HSCT) induces an immune response that facilitates graft acceptance, but if clinically apparent as acute graft-versus-host disease (aGvHD), it may adversely affect transplantation outcomes. TH17 cells are involved in the inflammatory processes associated with several diseases, including inflammatory bowel disease (IBD) as a prototype. In this study we investigated the presence of IL-17-producing cells among peripheral blood mononuclear cells (PBMC) of patients after HSCT. The 48 patients of median age 45 years (range, 1.0-64 years), experienced hematologic malignancies (n=45) or nonmalignant disorders (n=3), treated with matched unrelated (n=24) or sibling (n=24) transplants. We examined IL-17-producing cells in alloreactive reactions after HSCT. PBMC were stimulated with BD Leukocyte Activation Cocktail (Ionomycin, Brefeldin A, and phorbol myristic acetate (PMA)) in the presence of BD GolgiStop. After stimulation the cells were labeled with anti-CD4 and intracellular anti-IL-17A monoclonal antibodies. IL-17+ cell proportions were analyzed in the CD4+ lymphocyte gate. We observed that patients at the time of hematologic reconstitution had higher proportions of IL-17-producing cells than healthy control subjects (0.73±0.13 vs 0.19±0.06%; P=.019). Fourteen patients displayed the first symptoms of aGvHD at the time of hematologic reconstitution, when they showed lower proportions of IL-17+ cells among CD4+ lymphocytes than their counterparts lacking aGvHD at a similar time after transplantation (0.29±0.09 vs 0.73±0.13%; P=.024). Eight patients developed aGvHD after hematologic reconstitution (median, 34 days). All of these patients displayed lower proportions of IL-17-producing CD4+ cells on the day of aGvHD compared with their initial measurements preceding this complication (0.34±0.14 vs 1.07±0.37%; P=.01).