ApoE基因与人类老年性疾病的关系及ApoE基因敲除小鼠在人类老年疾病研究中的应用

心脑血管疾病的病因与发病机制非常复杂,病毒因素、遗传因素、染色体及免疫功能都与其相关.目前已经发现多个基因与心脑血管疾病发生有关,其中,载脂蛋白E(Apo E)基因在心脑血管疾病中的作用被越来越多的认识.国外通过对大规模的人群进行分析,发现ApoE基因的多态性和老年性疾病息息相关[1].     

莱菔子水溶性生物碱对ApoE基因敲除小鼠内皮细胞的抗氧化保护作用

目的 探讨莱菔子水溶性生物碱对ApoE基因敲除小鼠内皮细胞抗氧化保护作用.方法 将50只ApoE基因敲除小鼠随机分为5组:模型组、莱菔子水溶性生物碱高、中、低剂量组、血脂康组,每组10只;另取10只C57BL/6J作为空白组.8 w后,眼球取血处死,随机选取6个样本检测指标.结果 与模型组相比,莱菔子各剂量组均能明显提高ApoE基因敲除小鼠血清NO含量(P＜0.05);提高血清SOD的活性(P＜0.05);降低血清MDA(P＜0.01)含量.结论 莱菔子水溶性生物碱通过提高ApoE基因敲除小鼠血清NO含量、提高SOD活性、降低MDA含量,发挥抗氧化作用,从而保护内皮细胞.     

高脂喂养对ApoE基因敲除小鼠胆固醇代谢相关基因表达的影响

建立高脂诱导载脂蛋白E基因敲除(ApoE-/-)小鼠胰岛素抵抗模型,探讨其对胆固醇代谢相关基因表达的影响.结果 显示高脂喂养组ApoE-/-小鼠空腹血糖、游离脂防酸、总胆固醇、甘油三酯、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)和空腹血浆胰岛素水平明显高于对照组(均P＜0.01);肝组织中INSIG2和SCAP mRNA明显升高(P＜0.05或P＜0.01),肝INSIG2蛋白水平也明显增高(P＜0.05);而SREBP1 mRNA表达明显降低(P＜0.05).这些改变可能在该小鼠模型胆固醇代谢紊乱和胰岛素抵抗的发生中具有一定的作用.

Abstract：

To investigate the effect on gene expression related cholesterol metabolism in ApoE-/- mice with high-fat-induced insulin resistance(IR). In high-fat fed mice, FBG, FFA, TC, TG, LDL-C, HDL-C, and fasting plasma insulin were significantly higher than those of controls(P＜0.01). The INSIG2 and SCAP mRNA expressions in liver were significantly increased in high-fat fed mice compared with controls(P＜0. 05 or P＜0.01), and INSIG2 protein levels also increased(P＜0. 05). But SREBP1 mRNA expression in liver of high-fat fed mice was significantly reduced(P＜0. 05). These changes might contribute to IR and disorder of cholesterol metabolism in high-fat fed ApoE-/- mice.     

高脂诱导胰岛素抵抗ApoE基因敲除小鼠糖脂代谢的变化

目的建立高脂诱导ApoE基因敲除（ApoE^-/-）小鼠胰岛素抵抗（IR）模型,并探讨其糖脂代谢的变化。方法高脂喂养ApoE叫小鼠16周建立IR模型,采用3-^3H葡萄糖为示踪剂的扩展高胰岛素钳夹技术评价其胰岛素敏感性和糖脂代谢变化。结果普通饲料喂养ApoE^-/-小鼠（NF组）血浆FFA、TC、TG、LDL-C、HDL-C和Ins明显高于C57BL／6J小鼠对照（NC）组（P〈0．01和P〈0．05）,而高脂喂养ApoE叫小鼠（HF组）上述指标又明显高于NF组（P均〈0．01）,并且FBG也明显高于NF和NC组（P均〈0．01）。钳夹稳态时,HF组Ins明显高于NF和NC组（P均〈0．01）,FFA、TC、TG虽被抑制,但仍明显高于NF和NC组（P均〈0．01）;HF组葡萄糖输注率明显低于NF和NC组（P均〈0．01）。在钳夹结束时,HF组葡萄糖清除率明显低于NF和NC组（P均〈0．01）,而肝糖输出率则明显高于NF和NC组（P均〈0．01）,仅被抑制51％。结论ApoE^-/-小鼠存在糖脂代谢紊乱和IR的遗传特征,长期高脂饲养后更为明显。     

嗜黏蛋白阿克曼菌对高脂饲料诱导的肥胖ApoE基因敲除小鼠血脂代谢及炎症因子的影响

目的 观察嗜黏蛋白阿克曼(AKK)对高脂饲料喂养的肥胖ApoE基因敲除(ApoE-/-)小鼠血脂代谢及炎症因子相关指标的影响。方法 选取健康SPF级雄性C57BL/6J及ApoE-/- 4周龄小鼠,均给予高脂饲料喂养。喂养6周后,选取高于C57BL/6J小鼠平均体质量10%的ApoE-/-小鼠20只,随机编号,奇数为模型组(n=10),偶数为AKK干预组(n=10),C57BL/6J小鼠作为对照组(n=10)。对照组与模型组小鼠灌胃不含AKK的甘油制剂,AKK干预组灌胃含1×10⁹CFU AKK的甘油制剂。每日灌胃1次,每次0.1ml。灌胃4周后,称量小鼠空腹体质量,采集血清及附睾脂肪组织。检测血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)等血脂代谢指标水平,白细胞介素(IL)-1、IL-6、IL-8、IL-10、C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)及单核细胞趋化蛋白-1(MCP-1)等炎症因子指标水平。称量附睾脂肪组织质量,苏木精-伊红(HE)染色观察小鼠附睾脂肪组织细胞形态及大小,测量脂肪组织细胞平均面积。采用SPSS 26.0统计软件进行数据分析。多组间比较采用单因素方差分析。结果 灌胃4周后,与模型组相比,AKK干预组小鼠空腹体质量、附睾脂肪组织质量及体脂百分比均有下降趋势,但差异无统计学意义(P＞0.05);AKK干预组血脂代谢指标TG[(0.85±0.17)和(1.65±0.15)、(1.08±0.09)mmol/L]及LDL-C[(3.20±0.85)和(6.47±0.87)、(4.89±0.56)mmol/L]均显著低于模型组及对照组,HDL-C[(919.89±116.19)和(433.59±183.85)、(721.11±222.70)mmol/L]显著高于模型组及对照组,TC[(3.00±0.64)和(5.12±0.71)mmol/L]显著低于模型组,差异均有统计学意义(均P<0.05);AKK干预组炎症因子指标IL-1[(74.10±25.28)和(191.42±31.36)、(123.91±25.29)pg/ml]、IL-6[(63.10±9.53)和(100.76±11.42)、(77.76±8.20)pg/ml]、IL-8[(64.34±10.36)和(104.59±8.46)、(82.64±11.79)pg/ml]、CRP[(88.85±24.33)和(172.53±25.41)、(122.72±22.08)ng/ml]、TNF-α[(372.30±47.05)和(672.13±66.18)、(509.97±54.50)pg/ml]及MCP-1[(11.90±1.58)和(25.18±2.03)、(18.59±2.11)pg/ml]均显著低于模型组及对照组,差异均有统计学意义(均P<0.05),IL-10有升高趋势,但3组比较差异无统计学意义(P>0.05)。HE染色观察显示,AKK干预组较模型组小鼠附睾脂肪组织细胞平均面积[(330.45±55.84)和(879.58±36.74)μm²)]显著减小(P＜0.05),形态规整,单个视野下脂肪细胞数量明显增多。结论 AKK可改善高脂饲料喂养的肥胖ApoE-/-小鼠的血脂异常,并降低肥胖ApoE-/-小鼠血清炎症因子水平。     

超声生物显微镜在ApoE基因敲除小鼠动脉粥样硬化病变与C反应蛋白的相关性研究

目的:探讨超声生物显微镜(UBM)在监测ApoE基因敲除小鼠动脉粥样硬化(As)进程中的作用及As病变与C反应蛋白(CRP)的关系。方法:选用8,16,24及32w共32只ApoE-/-小鼠作为研究对象,并选用相同周龄C57BL/6小鼠作为对照,应用UBM追踪观察各周龄ApoE-/-小鼠主动脉根部内中膜厚度(IMT),检测血清CRP水平。结果:①UBM显示ApoE-/-组主动脉根部IMT厚度随着周龄增长而增长,各周龄ApoE-/-小鼠IMT厚度组间差异有统计学意义(P0.01)。对照组小鼠各周龄IMT差异无统计学意义。②UBM测量的各周龄ApoE-/-小鼠主动脉根部收缩期最大IMT值和对应血管部位横切面病理测值有明显相关性(r=0.81,P0.0001)。③ApoE-/-小鼠血清CRP水平较同周龄对照组升高(P0.01),且随着周龄增长,血清CRP水平呈逐渐升高趋势。ApoE-/-小鼠血清CRP水平和UBM测量的主动脉根部IMT值呈正相关(r=0.626,P0.001)。结论:①UBM可以监测ApoE-/-小鼠的As进程,IMT测量可作为判断和监测As病变的一个准确有效的指标。②血清炎症反应标志物CRP的增高与As有关,且与As的严重程度相关。     

LXR激动剂对ApoE基因敲除小鼠动脉粥样硬化的作用

观察肝孤核受体（LXR）激动剂（T-0901317）对ApoE基因敲除小鼠［ApoE（-/-）］主动脉结构和血管活性的影响,探讨LXR激动剂对抑制动脉粥样硬化（AS）病变形成的作用及潜在机制。方法： 12周龄ApoE基因敲除小鼠随机分为AS模型对照组（AS组）与LXR激动剂干预组（AS＋LXR组）,将有相同遗传背景的同龄正常C57BL/6J小鼠分为正常对照组（CON组）与单纯药物干预组（CON＋LXR组）。CON＋LXR组、AS＋LXR组LXR激动剂连续灌胃6周,剂量为10 mg/（kg·d）。AS组、CON组灌服等量生理盐水。各组小鼠在处理6周后进行外周血采集检测血脂,并分离主动脉, 透射电镜观察血管超微结构,Western blot测定主动脉壁中三磷酸腺苷结合盒转运体A1（ABCA1）蛋白的表达水平。结果： AS＋LXR组血浆总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）均显著低于AS组（P〈0.01）,高密度脂蛋白胆固醇（HDL-C）高于AS组（P〈0.05）。AS组主动脉内膜呈明显粥样硬化斑块形成特点,AS＋LXR组内皮变性坏死比AS组明显减低。与AS组比较,AS＋LXR组的AS病变面积显著降低,同时动脉壁中ABCA1的表达显著增强。结论： LXR激动剂T-0901317能够显著改善血脂,对主动脉内膜超微结构有良好的修复和保护作用,对高脂饲养的ApoE基因敲除小鼠的AS形成具有抑制作用,其作用机制可能与LXR激动剂上调动脉壁巨噬细胞中ABCA1蛋白的表达、增强胆固醇逆转运有关。     

LXR激动剂对和ApoE基因敲除小鼠动脉粥样硬化的作用

目的:观察肝孤核受体(LXR)激动剂(T-0901317)对ApoE基因敲除小鼠[ApoE(-/-)]主动脉结构和血管活性的影响,探讨LXR激动剂对抑制动脉粥样硬化(AS)病变形成的作用及潜在机制.方法:12周龄ApoE基因敲除小鼠随机分为AS模型对照组(AS组)与LXR激动剂干预组(AS+LXR组),将有相同遗传背景...     

厄贝沙坦抑制高胆固醇诱导载脂蛋白E基因敲除小鼠动脉粥样硬化的炎症机制

目的探讨厄贝沙坦对载脂蛋白E基因敲除小鼠动脉粥样硬化斑块的影响及炎症机制。方法载脂蛋白E基因敲除小鼠随机分为普食组、高胆固醇饮食组、高胆固醇饮食 厄贝沙坦组,每组15只,分别予蒸馏水、蒸馏水、厄贝沙坦10 mg/(kg.d)灌胃12周。无创血压系统测小鼠血压;内眦动脉取血检测血清总胆固醇和甘油三酯水平;冰冻切片光镜下定位主动脉根部,油红O染色评估斑块大小;实时定量聚合酶链反应和Western blotting方法检测主动脉肿瘤坏死因子α、白细胞介素6、单核细胞趋化蛋白1和血管细胞粘附分子1的表达。结果高胆固醇饮食组小鼠血脂水平明显升高(P<0.01),且斑块面积明显高于普食组(P<0.01);厄贝沙坦明显减小斑块面积(P<0.01),同时降低肿瘤坏死因子α、白细胞介素6、单核细胞趋化蛋白1和血管细胞粘附分子1的表达(P<0.01)。结论血管紧张素Ⅱ1型受体拮抗剂厄贝沙坦可以通过降低炎症因子的表达,从而达到抑制动脉粥样硬化发生发展的目的。     

沉默胆固醇调节原件结合蛋白2基因对炎症因子所致HepG2细胞内胆固醇异常积聚的影响

目的 探讨沉默胆固醇调节原件结合蛋白(SREBP)2对炎症因子所致HepG2细胞内脂质异常积聚的影响.方法 通过脂质体转染SREBP2-shRNA质粒、G418抗性筛选HepG2细胞,建立沉默SREBP2的HepG2稳定细胞株(SREBP2 shRNA-HepG2)及阴性对照质粒HepG2稳定细胞株(NC shRNA-HepG2).对两种细胞分别给予无血清培养处理(对照组)、炎症因子[肿瘤坏死因子(TNF)α20ng/ml]、高脂[低密度脂蛋白(LDL) 100 μ g/ml]和联合干预(20ng/ml TNFα +100μg/ml LDL)处理.油红O染色及酶法检测细胞中脂质积聚情况,实时定量PCR和Western blot 分别检测SREBP2及其下游靶基因低密度脂蛋白受体(LDLr)和3-羟-3-甲基戊二酰辅酶A(HMGCoA)还原酶的基因和蛋白表达情况.对数据用单因素方差分析及2×2×2析因设计方差分析比较. 结果 成功建立阴性对照稳定细胞株NC shRNA-HepG2及抑制SREBP2表达的稳定细胞株SREBP2shRNA-HepG2.在NC shRNA-HepG2细胞中,TNF α处理使细胞内胆固醇积聚增加,并能上调SREBP2下游靶基因LDLr、HMGCoA还原酶基因和蛋白的表达,其mRNA相对表达量分别为1.68±0.03、1.31±0.05,F值分别为107.42,59.08,P值均＜0.01 ;其蛋白相对表达量分别为1.49±0.10、1.54±0.06,F值分别为46.24,247.10,P值均＜0.01.而在SREBP2 shRNA-HepG2细胞中,TNFα对胞内胆固醇沉积的作用可以被明显减弱,进一步基因和蛋白检测结果显示,炎症因子TNF α对LDLr、HMGCoA还原酶的上调作用亦被明显抑制. 结论 炎症因子通过促进SREBP2及其下游靶基因表达致HepG2细胞内胆固醇异常积聚,而通过RNA干扰抑制SREBP2的表达,可以明显减轻炎症因子所致的细胞内胆固醇的异常积聚.     

生酮饮食诱导db/db小鼠肝脏脂肪沉积

目的 ：研究生酮饮食（ketogenic diet,KD）对db/db小鼠肝脏脂质沉积的影响及其机制,探讨KD治疗db/db小鼠的安全性。方法：选用8周龄db/db雄性小鼠20只作为肥胖2型糖尿病（type 2 diabetes mellitus,T2DM）动物模型,适应性喂养3周后,最终18只纳入研究,随机数字表法分为正常喂养（ND）组、KD组、75%热量限制（calorie restriction,CR）组,每组6只。另将8周龄C57BL/6雄性小鼠6只作为正常对照（C）组,以标准饲料喂养。C组、ND组自由进食标准饲料,KD组自由进食生酮饲料,CR组作为阳性对照组,每日摄入ND组75%的标准饲料。干预4周后,由于实验过程中KD组及CR组分别有2只及1只小鼠不明原因死亡,按随机数字表法每组纳入3只小鼠进行统计分析。检测各组小鼠空腹甘油三酯（triglyceride,TG）、总胆固醇（total cholesterol,TC）及低密度脂蛋白胆固醇（low density lipoprotein cholesterol,LDL-C）水平;观察小鼠肝脏形态和结构及肝脏组织中脂滴大小和数量;...     

抵抗素上调脂肪酸转位酶表达对HepG2细胞脂质积聚的作用

目的探讨抵抗素在棕榈酸诱导下对HepG2肝细胞脂质积聚的作用及其对脂肪酸转位酶(FAT/CD36)表达调控的影响。方法 50 ng/ml重组人抵抗素及0.5 mmol/L棕榈酸孵育HepG2肝细胞,之后用100 nmol/L胰岛素处理,采用实时定量RT-PCR检测胆固醇调节元件结合蛋白(SREBP)1 mRNA水平,流式细胞仪检测胞膜CD36表达,尼罗红(Nile Red)染色后激光共聚焦显微镜检测胞内脂质含量。结果与对照组相比,抵抗素增加胞膜FAT/CD36含量(P<0.05),促进HepG2细胞SREBP1 mRNA表达(P<0.05),使胞内红色脂肪小滴增多(P<0.05)。结论在高浓度游离饱和脂肪酸环境中,抵抗素在基础及胰岛素刺激状态下通过上调HepG2的CD36表达,刺激SREBP1转录,导致HepG2肝细胞内脂质积聚。     

量子降脂仪对高脂血症大鼠血脂的影响及其机制

目的观察量子降脂仪对高脂血症模型大鼠的降血脂作用并探讨其机制。方法以高脂饲料和10%果糖自由饮水建立无特定病原体动物(SPF)级大鼠高脂血症模型。量子降脂仪输出功率强度为70μW/(cm2·min),每天治疗1～2次,治疗时间为每次5～10 min。采用Elisa试剂盒检测血清中血脂水平,Western blot方法检测脂类代谢和炎症通路关键蛋白表达水平的变化。结果量子降脂仪明显改善由高脂血症引起的的血脂代谢紊乱、调节血脂平衡、降低炎症状态、缓解肝功能损伤、缓解氧化损伤、提高脂肪代谢相关酶的活性、抑制脂肪酸合成酶的活性。Western blot结果显示,量子降脂仪通过调节核因子κB(NF-κB)、肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)蛋白的表达水平,缓解机体慢性炎症;通过调节过氧化体增殖物激活型受体α(PPARα)蛋白的表达水平促进机体脂质代谢;通过调节胆固醇调节元件结合蛋白2(SREBP-2)通路,促进低密度脂蛋白受体(LDLR)蛋白表达,缓解脂质代谢紊乱,调节机体高胆固醇和高甘油三酯水平。结论量子降脂仪具有明显降血脂作用,可作为降血脂医疗器械辅助应用于临床。     

Absence of CD36 protects against atherosclerosis in ApoE knock-out mice with no additional protection provided by absence of scavenger receptor A I/II

AIMS: The role of scavenger receptors in atherogenesis is controversial as a result of conflicting reports and a recent hypothesis suggesting that scavenger receptor absence would enhance the pro-inflammatory, pro-atherogenic milieu. This study addresses the effect of combined absence of scavenger receptors CD36 and SRA I/II on atherosclerosis lesion development in the apolipoprotein E knock-out (apoE degrees ) model. METHODS: We created background-related strains of apoE degrees , scavenger receptor A I/II knock-out (SRA degrees )/apoE degrees , CD36 knock-out (CD36 degrees )/apoE degrees , and CD36 degrees /SRA degrees /apoE degrees mice that were >99% C57Bl/6. Four-week-old mice were fed a Western diet for 12 weeks and were assessed for lesion burden/morphology, risk factors for atherosclerosis, inflammatory mediators, and macrophage function. RESULTS: There was a 61 and 74% decrease in total aortic lesion area in CD36 degrees /apoE degrees males and females, respectively, compared with apoE degrees controls. The absence of SRA was protective (32% decrease in lesion) in female mice. The combined absence of CD36 and SRA provided no further protection in either gender. Macrophages from mice lacking CD36 had decreased pro-inflammatory characteristics and less migration to a pro-inflammatory stimulus. Plasma levels of cytokines/chemokines showed that CD36 degrees /apoE degrees and CD36 degrees /SRA degrees /apoE degrees mice had a less pro-inflammatory phenotype compared with apoE degrees and SRA degrees /apoE degrees mice. Oblivious mice in the apoE degrees background ruled out potential 'passenger gene' effects in the case of CD36. CONCLUSION: These results provide new insights into the pro-atherogenic mechanisms of CD36 by implicating processes other than modified lipoprotein uptake.     

Short-term inhibition of SREBP-1c expression reverses diet-induced non-alcoholic fatty liver disease in mice

Abstract

Objective. The present study investigates the level of Sterol-regulatory element-binding proteins (SREBP-1c) and related proteins in obese mice (DIO) treated with SREBP-1c antisense oligonucleotide (ASO) to observe a reversal of steatosis. Materials and methods. Swiss mice were fed on chow containing 61 kJ% saturated fat for 8 weeks to develop obesity. After this period, one group of animals was used to assess the molecular effects of SREBP-1c antisense oligonucleotide treatment by immunoblot analysis in a dose-response curve (0; 1.0; 2.0; 3.0; 4.0 nmol/day). After the dose (3.0 nmol/day) was determined, another group was treated for 14 days. After a period of 24 h following the last injection mice were killed and plasma and hepatic tissue were obtained to evaluate plasma triglycerides and total liver fat. Western blot was performed to evaluate SREBP-1c, FAS, SCD-1, PPARγ and CPT1 expression and AMPK[Thr172] and ACC[Ser79] phosphorylation. Livers were stained using the hematoxylin and eosin method for histological analysis. Results. Body weight, epididymal fat and glucose levels were not affected by one daily dose of ASO. However, total plasma triglycerides and total liver fat were significantly reduced. Also, this treatment inhibited SREBP-1c and reduced protein levels of a series of proteins involved in lipogenesis, including ACC, FAS and SCD-1. Moreover, mice treated with ASO presented a significant reduction in macroscopic and microscopic features of hepatic steatosis. Conclusion. Our results demonstrate that the inhibition of SREBP-1c decreased the expression of lipogenic enzymes, reducing the accumulation of triglycerides and, finally, reversing hepatic steatosis in mice.     

Ultrastructure of early lipid accumulation in ApoE-deficient mice

Apolipoprotein (apo) E-deficient mice develop severe hypercholesterolemia and have lesions that progress from fatty streaks to fibrous plaques distributed in lesion-prone areas throughout the aorta. Lesions develop in apoE-deficient mice on a regular chow diet and will occur faster on a diet higher in cholesterol. Examination of the aortas from these mice on a chow diet by high-resolution, freeze-etch electron microscopy demonstrated lipid retention in the intima by 3 weeks of age. Lipid was retained in the matrix as individual particles between 33 and 48 nm in diameter, aligned along the collagen fibrils and in aggregates consisting of lipid particles with average diameters of 33 and 68 nm. Larger particles seemed to have formed from fusion of smaller particles. Lipid retention was more widespread in 5- and 9-week-old mice. Monocyte attachment to endothelial cells was observed by electron microscopy at 5 weeks of age. The appearance of the intimal lipid was similar to that previously described in rabbit models and suggests that lipid interaction with matrix filaments and subsequent aggregation of lipid particles are critical first steps in the process of foam cell formation.     

Deficiency of CD73/ecto-5'-nucleotidase in mice enhances acute graft-versus-host disease

Extracellular ATP and adenosine have immunoregulatory roles during inflammation. Elevated extracellular ATP is known to exacerbate GVHD, and the pharmacologic activation of the adenosine A2A receptor is protective. However, the role of endogenous adenosine is unknown. We used gene-targeted mice and a pharmacologic inhibitor to test the role of adenosine generated by CD73/ecto-5'-nucleotidase in GVHD. In allogeneic transplants, both donor and recipient CD73 were protective, with recipient CD73 playing the dominant role. CD73 deficiency led to enhanced T-cell expansion and IFN-γ and IL-6 production, and the migratory capacity of Cd73-/- T cells in vitro was increased. However, the number of regulatory T cells and expression of costimulatory molecules on antigen-presenting cells were unchanged. A2A receptor deficiency led to increased numbers of allogeneic T cells, suggesting that signaling through the A2A receptor via CD73-generated adenosine is a significant part of the mechanism by which CD73 limits the severity of GVHD. Pharmacologic blockade of CD73 also enhanced graft-versus-tumor activity. These data have clinical implications, as both the severity of GVHD and the strength of an alloimmune antitumor response could be manipulated by enhancing or blocking CD73 activity or adenosine receptor signaling depending on the clinical indication.