Ly49A基因转染的淋巴细胞对H-2~d小鼠正常和肿瘤细胞杀伤活性的实验研究

目的　观察Ly49A基因转染的C5 7BL/ 6小鼠的淋巴细胞对BALB/c小鼠正常成纤维细胞和 4T1乳腺癌细胞杀伤能力的变化与差异。方法　构建逆转录病毒表达载体pLXSN Ly49A ,经由PA317包装细胞包装后转染C5 7BL/ 6小鼠淋巴细胞。流式细胞仪检测Ly49A受体在转染后淋巴细胞上的表达率。MTT法检测转染后淋巴细胞对BALB/c小鼠正常成纤维细胞和 4T1乳腺癌细胞的杀伤活性 ,以空载体转染和未转染的淋巴细胞作对照。结果　Ly49A基因转染的C5 7BL/ 6小鼠的淋巴细胞 2 4h后Ly49A受体表达率为 (4 6 .6 7± 0 .35 ) % ,空载体转染组为 (18.73± 0 .85 ) % ,未转染对照组为 (19.6 0± 0 .2 7) % ,其对BALB/c小鼠正常成纤维细胞的杀伤活性明显降低 (抑制率 2 2 %～ 2 5 % ) ,对 4T1乳腺癌细胞的杀伤活性无明显改变 (P >0 .0 5 )。结论　转染Ly49A的C5 7BL/ 6小鼠淋巴细胞对BALB/c小鼠正常细胞的杀伤作用明显降低 ,但仍保留了对肿瘤细胞的杀伤活性 ,为解决异基因骨髓移植后移植物抗宿主病提供了实验依据     

Ly49A转基因小鼠脾细胞对半相合异基因骨髓移植后GVHD和GVL的作用

目的　观察Ly4 9A基因转染的C5 7BL 6小鼠脾细胞对半相合异基因骨髓移植 (allo BMT)后移植物抗宿主病 (GVHD)和移植物抗白血病效应 (GVL)的影响。方法　经由逆转录病毒介导将Ly4 9A基因转染至C5 7BL 6小鼠的脾细胞 ;流式细胞仪检测Ly4 9A受体在转染后脾细胞上的表达率 ;以亲代C5 7BL 6H 2 b 小鼠为供者 ,以接种EL96 11红白血病细胞的 (BALB c×C5 7BL 6 )F1H 2 d b(CB6F1)小鼠为受者 ,预处理条件为全身照射 (TBI,6 0 Co照射 10 .5Gy) ,进行脾细胞混合骨髓细胞移植 ,建立半相合异基因急性GVHD模型并在该模型基础上观察Ly4 9A基因转染的脾细胞对GVHD和GVL的作用。结果　Ly4 9A基因转染的C5 7BL 6小鼠的脾细胞 2 4h后蛋白表达率为 (42 .2 0± 4 .87) % ,空载体转染组为(18.6 7± 2 4 8) % ,未转染对照组为 (18.73± 3.82 ) % ,在半相合异基因移植中 (C5 7BL 6 H 2b →CB6F1H 2d b) ,未进行移植的单纯照射组生存期为 (7.80± 3.36 )d ;环磷酰胺治疗组生存期为 (2 1.70±2 87)d ;脾细胞混合骨髓细胞移植组生存期为 (2 9.4 0± 6 .4 3)d ;空载体转染的脾细胞混合骨髓细胞移植组生存期为 (2 9.10± 7.39)d ;Ly4 9A转染的脾细胞混合骨髓细胞移植组生存期为 (45 .0 0± 12 .38)d ,较上述各组生存期明显延长 (P     

通过Fas-FasL途径体外清除小鼠同种异体反应性T细胞

目的　通过Fas Fas配体 (FasL)途径清除小鼠同种异体反应性T细胞 (ARTC) ,为减轻异基因骨髓移植 (allo BMT)后的移植物抗宿主病探索新的手段。方法　用磁性细胞分离系统分离BALB c小鼠 (H 2 d)Sca 1+早期造血细胞 (HC) ,然后借助逆转录病毒基因转移技术对其转染外源小鼠FasL(mFasL)cDNA基因 ;扩增 1周后与异基因BAC小鼠 (H 2 d ×b)脾细胞进行单向混合淋巴细胞培养(OWMLC) 6d ,观察处理后的BAC小鼠脾细胞对Na251 CrO4标记的BALB c小鼠脾细胞的杀伤作用。结果　成功分离出BALB c小鼠Sca 1+HC ,纯度为 (89.0± 6 .1) %。BAC小鼠脾细胞与转染外源mFasL的BALB cHC以 1∶5比例共培养 6d后 ,对BALB c源脾细胞杀伤率在不同效、靶比例时均呈显著降低 (P<0 .0 1)。结论　体外反应中 ,转染外源mFasLcDNA并高表达的早期HC可清除针对自身MHC抗原的ARTC。     

OX40L在C57BL/6与BALB/c小鼠组织的差异性表达及分析

背景:有研究发现C57BL/6小鼠对动脉粥样硬化易感,而BALB/c小鼠却对动脉粥样硬化不易感.OX40L的表达情况与动脉粥样硬化的狭窄程度和心肌梗死的严重度相关,其在两种品系小鼠中是否存在表达差异?目的:分析0X40L在BALB/c和C57BU6小鼠心脏、大脑、肾脏、骨骼肌和脾脏组织的表达差异.方法:取C57BL/6和BALB/c小鼠心脏、大脑、肾脏、骨骼肌和脾脏组织,以Trizol提取总RNA, RIPA Buffer提取组织总蛋白.采用RT-PCR和Westem Blot方法检测两种品系小鼠心脏、脑、肾脏、脾脏和骨骼肌的OX40LmRNA和蛋白的表达.OX40L在两种品系小鼠不同器官间的表达差异.结果与结论:RT-PCR结果显示,C57BL/6小鼠心脏OX40LmRNA表达显著高于BALB/c小鼠(P＜0.05),脾脏OX40LmRNA表达明显低于BALB/c小鼠(P＜0.05),两种品系小鼠大脑、肾脏及骨骼肌OX40LmRNA表达差异无显著性意义;Western Blot结果显示,两种品系小鼠OX40L的蛋白表达均在心脏最高;C57BL/6小鼠心、脑及肾OX40L蛋白表达均显著高于BALB/c小鼠(P＜0.05),两种品系小鼠骨骼肌和脾脏OX40L蛋白表达差异无显著性意义.两个品系小鼠OX40L mRNA的表达水平与蛋白表达水平不完全一致.C57BL/6小鼠心脏中OX40L mRNA转录水平较BALB/c高,但在脾脏中表达量较后者低;C57BL/6小鼠心脏、大脑和肾脏OX40L蛋白水平均较BALB/c小鼠高;两种品系小鼠之间的表达差异提示OX40L可能与C57BL/6小鼠易感动脉粥样硬化有关.     

巨细胞病毒对小鼠心脏移植术后急性排斥反应的影响

目的观察巨细胞病毒（cytomegalovirus,CMV）感染对同种异基因小鼠腹腔异位移植心脏急性排斥反应的影响。方法 BALB/c小鼠80只,C57BL/6小鼠40只,按供、受鼠基因不同分为3组（每组20对）：同质移植组（A组,BALB/c→BALB/c）、环胞素A组（B组,C57BL/6→BALB/c）和小鼠巨细胞病毒联合环胞素A组（C组,C57BL/6→BALB/c）,施行小鼠腹腔异位心脏移植术。A组无药物干预,B组术后腹腔注射CsA 20mg/kg.d,C组除腹腔注射CsA 20mg/kg.d外,术后第1d腹腔接种104PFU小鼠巨细胞病毒（MCMV）0.2ml。术后观察移植鼠心脏跳动情况、移植心脏存活时间、移植心脏的病理组织学以及MCMV病毒滴度测定。结果术后10d,A组移植心脏几乎无排斥反应;B组移植心脏搏动有力,显微镜下观察移植心脏心肌间质内有局灶性炎症细胞浸润,心肌有变性;C组移植心脏搏动微弱,体积增大,重量增加,显微镜下见心内、外膜下及心肌间质有弥漫性淋巴细胞及单核细胞浸润;心肌细胞可发生变性、坏死。C组（12.4±1.3d）移植心脏存活时间明显低于B组（16.7±1.9d）（P〈0.01）,而A组移植心脏长期存活（观察60d）。结论巨细胞病毒感染加速小鼠腹腔异位移植心脏急性排斥反应。     

同种与异种胎胸腺混合移植诱导供者皮肤移植免疫耐受

目的:探讨同种异种胎胸腺混合移植达到供者皮肤移植的耐受。方法:实验于2003-03/12在第三军医大学创伤、烧伤、复合伤实验室完成。将F344大鼠胎胸腺和C57BL/6小鼠胎胸腺混合移植到BALB/C裸小鼠的双肾包膜下4个月后,用流式细胞仪技术检测裸小鼠外周血中CD3+和CD4+T细胞,用单向混合淋巴细胞培养了解T细胞对ConA以及同种异种淋巴细胞的反应性,异基因皮肤移植观察皮肤移植物存活期。结果:①混合移植胎胸腺4个月后,受者裸小鼠外周血中CD3+和CD4+T细胞占总白细胞的25.9%,正常裸小鼠外周血中CD3+和CD4+量极少(2.43%)。②受者T细胞对ConA以及无关的SD鼠异种淋巴细胞的反应性强(刺激指数分别为23.23与12.75),而对供者F344及C57BL/6淋巴细胞不发生增殖反应(刺激指数分别为1.12与0.98)。③受者对供者F344及C57BL/6鼠皮肤移植物86d不发生排斥,而对无关的SD鼠皮肤移植物15d即发生排斥。结论:受体对胸腺供体来源的F344和C57BL/6皮肤及宿主本身的BALB/C皮肤移植耐受,而对无关的SD鼠皮肤移植物较短时间内即发生了排斥,并且抗DNA自身抗体水平与正常鼠相似。表明同种和异种胸腺混合移植后受体可重建有免疫功能的T淋巴细胞,并能诱导供者特异性免疫耐受的发生。     

在小鼠骨髓移植中CCR5与急性移植物抗宿主病的相关性研究

本研究评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用,为今后的异基因造血干细胞移植的临床应用提供科学依据.经过致死剂量照射的BALB/c小鼠接受异基因C57BL/6小鼠的骨髓移植.根据回输的细胞不同实验分为4组:B6 CCR5 KO组,受者接受C57BL/6 CCR5-/-小鼠骨髓和脾脏细胞;B6 WT组,受者接受野生型C57BL/6小鼠骨髓和脾脏细胞;B6 CCR5 KO BMC组,受者只接受C57BL/6 CCR5-/-小鼠骨髓细胞;B6 WT BMC组,受者只接受野生型C57BL/6小鼠骨髓细胞.结果表明:较之B6 WT组,B6 CCR5 KO组小鼠以更快的速度死于急性GVHD;其受者体内的CD8+T细胞更大量的增殖;其T细胞恢复后产生更多的INF-γ和TNF-α并且由于其T细胞有丝分裂原刀豆素水平处于较高水平,从而进一步促进T细胞的增殖,提示CCR5的作用之一是下调参与排异反应的供者CD8+T细胞的增殖.组织学评价提示,移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在有更为严重的病理变化.结论:剔除CCR5基因的异基因骨髓移植使GVHD发病率的增加,供者CD8+T细胞在受者体内增殖增加以及肝肾损害加重,这提示CCR5在异基因骨髓移植中起着重要作用.     

过继免疫HIFU治疗后活化T淋巴细胞在荷瘤鼠肿瘤局部的功能变化

目的 探讨过继免疫高强度聚焦超声(HIFU)治疗H22移植性肝癌后活化的T淋巴细胞在荷瘤鼠肿瘤局部的功能变化.方法 32只C57BL/6J近交系正常小鼠在H22肝癌移植后7天分别接受HIFU治疗(HIFU组,n=16)和HIFU假照治疗(假照组,n=16).治疗后14天,分离两组荷瘤鼠和正常C57BL/6J鼠(对照组,n=16)的脾淋巴细胞.以乳酸脱氢酶释放法测定各组小鼠脾淋巴细胞对H22细胞体外杀伤活性;另选30只C57BL/6J H22荷瘤鼠随机分为过继免疫HIFU组、过继免疫HIFU假照组和过继免疫对照组,分别静脉注射之前提取的淋巴细胞.输注7天后处死小鼠,手术取出肿瘤组织块,制成单细胞悬液,酶联免疫斑点法检测肿瘤局部T淋巴细胞的功能变化.结果 与假照组和对照组比较,HIFU组对H22细胞杀伤活性明显增强,差异有统计学意义(P均＜0.01);淋巴细胞过继免疫治疗后7天,与过继免疫假照组和过继免疫对照组比较,过继免疫HIFU组能分泌INF-γ淋巴细胞数量明显增加,差异有统计学意义(P均＜0.01).结论 HIFU治疗H22移植性肝癌后,活化的T淋巴细胞在肿瘤局部发挥特异性抗肿瘤效应.     

新型免疫状态定量监测皮肤移植模型小鼠的特异性

背景：器官移植后如何监测受者的免疫状态,并预测排斥反应的发生,从而调整免疫抑制剂的用量是当前面临的重要问题。目的：探索新型免疫状态定量监测方法在小鼠皮肤移植模型中是否有抗原特异性。方法：建立C57→BALB/c皮肤移植排斥模型,分别输注C57/BALB/c混合脾细胞悬液及第三者对照DBA/BALB/c混合脾细胞,在细胞输注后检测2种混合细胞悬液比例变化及供体细胞杀伤率,同时设置BALB/c→BALB/c同系皮肤移植对照组,免疫低下裸鼠对照组及免疫抑制剂对照组与之对比。结果与结论：C57/BALB/c悬液-移植排斥模型组和C57/BALB/c悬液-移植排斥模型免疫抑制剂组小鼠对供体C57脾细胞有强烈的特异性杀伤作用,其中C57/BALB/c悬液-移植排斥模型免疫抑制剂组特异性杀伤作用稍弱,而输注第三者对照DBA/BALB/c混合脾细胞的小鼠细胞注射2～4h内没有明显特异杀伤作用,但免疫低下的裸鼠始终未表现出特异性杀伤。说明实验建立的抗原特异性免疫状态检测方法能够快速地检测出皮肤移植受体的免疫状态。     

新型免疫状态定量监测皮肤移植模型小鼠的特异性

背景:器官移植后如何监测受者的免疫状态,并预测排斥反应的发生,从而调整免疫抑制剂的用量是当前面临的重要问题.目的:探索新型免疫状态定量监测方法在小鼠皮肤移植模型中是否有抗原特异性.方法:建立 C57→BALB/c皮肤移植排斥模型,分别输注 C57/BALB/c 混合脾细胞悬液及第三者对照DBA/BALB/c混合脾细胞,在细胞输注后检测2种混合细胞悬液比例变化及供体细胞杀伤率,同时设置 BALB/c→BALB/c 同系皮肤移植对照组,免疫低下裸鼠对照组及免疫抑制剂对照组与之对比.结果与结论:C57/BALB/c悬液-移植排斥模型组和C57/BALB/c悬液-移植排斥模型免疫抑制剂组小鼠对供体 C57 脾细胞有强烈的特异性杀伤作用,其中C57/BALB/c悬液-移植排斥模型免疫抑制剂组特异性杀伤作用稍弱,而输注第三者对照DBA/BALB/c混合脾细胞的小鼠细胞注射2~4 h内没有明显特异杀伤作用,但免疫低下的裸鼠始终未表现出特异性杀伤.说明实验建立的抗原特异性免疫状态检测方法能够快速地检测出皮肤移植受体的免疫状态.     

反转录病毒载体转染小鼠骨髓细胞

背景：为方便、准确检测外源细胞在体内的存活情况,需在外源细胞转移标记基因。目的：观察多种细胞因子联合刺激下反转录病毒载体对BALB/C×C57BL F1代小鼠骨髓细胞基因转移效率的影响。方法：以PA317-GCGPXSN细胞制备病毒上清,NIH3T3细胞测定病毒滴度后,取经过干细胞因子、白细胞介素3、白细胞介素6预培养刺激后的BALB/C×C57BL F1代小鼠骨髓细胞,实验组实施基因转移,流式细胞仪及PCR方法测定基因转移效率。阴性对照组不做基因转移。阳性对照组为PA317-GCGPXSN细胞株。结果与结论：①病毒滴度为1.9×108CFU/L。②对照组 BALB/C×C57BL F1代小鼠骨髓细胞测定的荧光强度数值为0.63%,实验组为76.04%,两组相比差异有显著性意义（P〈0.01）。PCR方法扩增到了NeoR基因的特异性片断,结果证实细胞因子预刺激后实施基因转移,可有效地将外源基因转移进入BALB/C×C57BL F1代小鼠骨髓细胞基因组中。     

反转录病毒载体转染小鼠骨髓细胞

背景:为方便、准确检测外源细胞在体内的存活情况,需在外源细胞转移标记基因。目的:观察多种细胞因子联合刺激下反转录病毒载体对BALB/C×C57BL F1代小鼠骨髓细胞基因转移效率的影响。方法:以PA317-GCGPXSN细胞制备病毒上清,NIH3T3细胞测定病毒滴度后,取经过干细胞因子、白细胞介素3、白细胞介素6预培养刺激后的BALB/C×C57BL F1代小鼠骨髓细胞,实验组实施基因转移,流式细胞仪及PCR方法测定基因转移效率。阴性对照组不做基因转移。阳性对照组为PA317-GCGPXSN细胞株。结果与结论:①病毒滴度为1.9×108CFU/L。②对照组 BALB/C×C57BL F1代小鼠骨髓细胞测定的荧光强度数值为0.63%,实验组为76.04%,两组相比差异有显著性意义(P<0.01)。PCR方法扩增到了NeoR基因的特异性片断,结果证实细胞因子预刺激后实施基因转移,可有效地将外源基因转移进入BALB/C×C57BL F1代小鼠骨髓细胞基因组中。     

Innate immune response in Th1- and Th2-dominant mouse strains

C57BL/6 and BALB/c mice are prototypical Th1- and Th2-type mouse strains, respectively. In the present study, we attempted to characterize the innate immune response of macrophages from these mouse strains. Macrophages from C57BL/6 mice produced higher levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-12 than those from BALB/c mice after stimulation with macrophage-activating lipopeptide-2 (MALP-2, a synthetic TLR-2 ligand) or lipopolysaccharide (LPS, a TLR-4 ligand). The augmented IL-12 production by C57BL/6 macrophages increased interferon-gamma and, in contrast, decreased IL-13 production by CD4+ T cells. On stimulation with MALP-2 or LPS, C57BL/6 macrophages produced lysosomal enzyme and nitric oxide, effector molecules for bacterial killing, whereas BALB/c macrophages did not. Bactericidal activity of BALB/c macrophages was impaired relative to C57BL/6 macrophages when cells were infected with live bacteria in vitro. In a murine model of septic peritonitis induced by cecal ligation and puncture (CLP), BALB/c mice failed to facilitate bacterial clearance relative to C57BL/6 mice despite an augmented peritoneal leukocyte infiltration that was associated with increased peritoneal levels of cytokines/chemokines. BALB/c mice exhibited increased plasma and hepatic levels of cytokines/chemokines, resulting in an exaggerated systemic inflammation as determined by acute-phase proteins. Finally, BALB/c mice were vulnerable to CLP-induced lethality relative to C57BL/6 mice. Altogether, innate immune response of macrophages is different between these mouse strains, which may affect the development of Th1 and Th2 adaptive immunity in these strains. Reduced systemic inflammatory response in C57BL/6 mice that may result from an eminent local response appears to be beneficial during sepsis.     

Distinct MHC class I-dependent NK cell-activating receptors control cytomegalovirus infection in different mouse strains

Recognition of mouse cytomegalovirus (MCMV)-infected cells by activating NK cell receptors was first described in the context of Ly49H, which confers resistance to C57BL/6 mice. We investigated the ability of other activating Ly49 receptors to recognize MCMV-infected cells in mice from various H-2 backgrounds. We observed that Ly49P1 from NOD/Ltj mice, Ly49L from BALB mice, and Ly49D2 from PWK/Pas mice respond to MCMV-infected cells in the context of H-2D(k) and the viral protein m04/gp34. Recognition was also seen in the H-2(d) and/or H-2(f) contexts, depending on the Ly49 receptor examined, but never in H-2(b). Furthermore, BALB.K (H-2(k)) mice showed reduced viral loads compared with their H-2(d) or H-2(b) congenic partners, a reduction which was dependent on interferon γ secretion by Ly49L(+) NK cells early after infection. Adoptive transfer of Ly49L(+), but not Ly49L(-), NK cells significantly increased resistance against MCMV infection in neonate BALB.K mice. These results suggest that multiple activating Ly49 receptors participate in H-2-dependent recognition of MCMV infection, providing a common mechanism of NK cell-mediated resistance against viral infection.     

GRAFT-VS.-HOST REACTIONS IN RECIPROCAL HYBRID MICE : I. DISSOCIATION OF T-CELL ACTIVITIES IN THE MIXED LYMPHOCYTE REACTION AND TWO GRAFT-VS.-HOST ASSAYS

Spleen cells from BALB/c and C57BL/6 mice were tested for their reactivity against reciprocal hybrid tissues ((BALB/c x C57BL/6) F₁ and (C57BL/6 x BALB/c) F₁) in three assay systems: the mixed lymphocyte reaction (MLR); the Simonsen spleen-weight graft-vs.-host (GVH) assay; and a GVH mortality assay. It was shown that both F₁'s serve as equally effective stimulators of parental cells in the MLR. In the spleen-weight assay, BALB/c and C57BL/6 cells were equally active in a given host, but greater splenomegaly was observed in (BALB/c x C57BL/6) F₁ hosts regardless of the donor strain. By contrast, BALB/c cells were much less lethal than C57BL/6 cells in (BALB/c x C57BL/6) F₁ hosts than in (C57BL/6 x BALB/c) F₁ hosts, and to a lesser degree C57BL/6 cells were less lethal than BALB/c cells in (C57BL/6 x BALB/c) F₁ hosts. The possibility that modifying substances may differentially alter reactivity of parental lymphocytes and that considerations other than genotype determine the outcome of a GVH reaction are discussed in detail.     

Cutaneous leishmaniasis. The defect in T cell influx in BALB/c mice

Local cellular responses to cutaneous infection with Leishmania mexicana amazonensis were examined in susceptible (BALB/c) and resistant (C57BL/6) mouse strains by immunocytochemical and electron microscopic studies. Infection during the first 8 wk in both animal strains was characterized by progressively enlarging lesions, epidermal thickening and ulceration, and accumulation of eosinophils and Ia+ infected macrophages. Healing of C57BL/6 mouse lesions began after 12 wk of infection and was associated with local influx of both Th (L3T4+) and T cytotoxic/suppressor (Lyt-2+) cells into the dermis, and Ia antigen expression on epidermal keratinocytes. T lymphocyte infiltration was marked and intracellular parasites were scarce by 21 wk of C57BL/6 infection. Similarly, granulomas in C57BL/6 livers contained L3T4+ and Lyt-2+ T lymphocytes and no visible intracellular parasites by 21 wk of infection. In contrast, BALB/c mouse lesions continued to enlarge and never healed. Throughout the entire course of infection, T lymphocyte influx into the heavily infected dermis was minimal. Keratinocyte Ia expression was absent in BALB/c lesions. BALB/c livers were heavily infected by 18 wk of cutaneous infection, with few demonstrable T lymphocytes. A systemic absence of T cells could not be demonstrated in BALB/c mice. Both L3T4+ and Lyt-2+ T cells were found in the peripheral blood in normal numbers in both mouse strains. Our results support the role of T cells as important local effector cells in the healing response of murine cutaneous leishmaniasis. We suggest that local T lymphocyte infiltration may provide lymphokines, particularly IFN-gamma, that can activate infected macrophages to destroy the intracellular parasites. Alternatively, T cells may play a cytotoxic role, killing infected macrophages and allowing local humoral factors to destroy released extracellular parasites.     

Cellular basis of graft versus host tolerance in chimeras prepared with total lymphoid irradiation

BALB/c mice given allogeneic (C57BL/Ka) bone marrow cells after toal lymphoid irradiation become stable chimeras approximately 80% donor- type and 20% host-type cells in the spleen. The chimeras doe not develop graft vs. host disease (GVHD). Purified cells of C57BL/Ka origin from the chimeras mediated GVHD in lightly irradiated C3H (third party), but not in BALB/c (host-strain) mice. Thus graft vs. host tolerance in the chimeras could not be explained by complete immunodeficiency of donor-type cells, serum blocking factors, or suppressor cells of host (BALB/c) origin. Clonal deletion or suppression of lymphocytes reactive with host tissues remain possible explanations. The transfer of donor-type chimeric spleen cells to BALB/c recipients given 500-550 rad whole-body irradiation WBI led to stable mixed chimerism in approximately 50% of recipients. The cells were presumably acting as tolerogens because similarly irradiated BALB/c mice given (BALB/c X C57BL/Ka)F1 spleen or bone marrow cells also became stable mixed chimeras.     

体外转染mFasL-cDNA小鼠骨髓细胞预防移植物抗宿主病的实验研究

为了探讨通过Fas FasL途径清除骨髓移植物中T细胞后 ,预防移植物抗宿主病 (GVHD)的可能性 ,采用脂质体转移法将FasL cDNA转染雌性BALB/c小鼠骨髓细胞 ,证实其获得表达后 ,体外与雄性BAC (BALB/c×C57BL/ 6)小鼠骨髓移植物混合培养后输注给经致死照射的BALB/c鼠 ,然后观察受体鼠GVHD的表现、死亡率 ,进行组织病理学检查 ,骨髓细胞Y染色体及CFU S检测。结果表明 :实验组 10只小鼠 ,60天死亡 2只 ,4只有GVHD改变 ;对照组 10只 ,60天死亡 7只 ,10只均有GVHD改变 ;两组骨髓细胞Y染色体分析显示均有供体鼠来源的骨髓细胞植入 ;CFU S检测表明实验组动物体内 10天即有CFU S形成 ,移植后第 2 0天即达正常水平。结论 :转染mFasL cDNA小鼠骨髓细胞能有效地预防GVHD的发生 ,并能使受体造血功能获得重建。     

Increased atherosclerosis in streptozotocin-induced diabetic mice.

Premature and extensive atheroscleroses involving renal, peripheral, and cardiovascular sites remain major complications of diabetes mellitus. Controversy exists as to the contribution of hyperglycemia versus elevated local or systemic concentrations of insulin to atherosclerosis risk. In this report, we developed the first murine model susceptible to both atherosclerosis and diabetes to determine which diabetogenic factors contribute to vascular disease. C57BL/6 and BALB/c mice were treated with multiple low-dose streptozotocin (STZ) or control citrate buffer and fed rodent chow or an atherogenic-promoting (Ath) diet for 12-20 wk. STZ treatment resulted in sustained hyperglycemia (250-420 mg/dl) and a modest reduction in plasma insulin levels for both strains regardless of diet. Citrate-treated C57BL/6 mice fed the Ath diet showed extensive oil red O-staining fatty streak aortic sinus lesions (20,537+/-2,957 micron2), the size of which did not differ for Ath-fed mice treated with STZ (16,836+/-2,136 micron2). In contrast, hyperglycemic BALB/c mice fed the Ath diet showed a 17-fold increase in atherosclerotic lesion area (7,922+/-2,096 micron2) as compared with citrate-treated mice fed the Ath diet (467+/-318 micron2). Correlations between lesion size and plasma glucose levels were significant for BALB/c (r = 0.741, P < 0.009), but not C57BL/6 (r = 0.314, P<0.3) mice. Lesion size correlated significantly with plasma cholesterol for C57BL/6 (r = 0.612, P<0.03) but not BALB/c (r = 0.630, P<0.1) mice. Immunohistochemistry showed that aortic sinus lesions from both strains contained macrophages, but smooth muscle cells were clearly present in lesions of BALB/c mice. In summary, we present the first small animal model showing accelerated atherosclerosis in response to hyperglycemia. Fatty streaks resembled those of human type II lesions in that both macrophages and smooth muscle cells were evident. In addition, our results support the concept that hyperglycemia as opposed to hyperinsulinemia contributes heavily to risk of atherosclerosis.