附子多糖与阿霉素长循环热敏脂质体的抗肿瘤作用及其机制探讨

目的:观察附子多糖(MPS)与阿霉素(ADM)长循环热敏脂质体(ALTSL)联合靶向治疗荷肝癌H22小鼠的作用,并探讨其抗肿瘤作用机制。方法:以荷瘤小鼠的瘤重为指标,观察药物的抗肿瘤活性。以荷瘤小鼠的存活天数计算生命延长率。以乳酸脱氢酶释放法检测NK细胞的杀伤活性。以MTT比色法检测淋巴细胞的转化率。以流式细胞术检测肿瘤细胞的凋亡及p53、Fas、FasL和caspase-3的表达。用RT-PCR法测定IL-2mRNA及IL-12mRNA的表达。制作病理切片观察肿瘤、心、肝、肾脏的组织学变化,探讨抗肿瘤机制。结果:MPS ALTSL联合治疗对肿瘤的抑制作用比单一ALTSL靶向治疗更为显著,抑瘤率达80.4%,并可显著延长荷瘤小鼠的存活时间(P<0.01)。与对照组和ADM组比较,ALTSL可使NK细胞的杀伤活性显著增加,而MPS ALTSL则可使NK细胞的杀伤活性和淋巴细胞转化率进一步提高(P<0.01)。应用ALTSL可使脾细胞中IL-2mRNA和IL-12mRNA的表达明显增高;而MPS ALTSL则可使他们的表达进一步增强。病理切片的结果显示,热敏脂质体配合肿瘤局部加热,可使肿瘤细胞凝固坏死。联合应用MPS,可见肿瘤组织中出现大量的淋巴细胞浸润。结论:ALTSL能提高化疗药物ADM的抗肿瘤效果,并降低其心肺毒性,保护机体的免疫功能。MPS ALTSL能进一步诱导肿瘤细胞凋亡,激活并促进T细胞转化和NK细胞的杀伤活性,增强机体的免疫功能,发挥抗肿瘤的协同作用。     

rhIL-2与阿霉素长循环热敏脂质体靶向治疗肿瘤的协同作用

目的:观察重组人白细胞介素-2(rhIL-2)与阿霉素长循环热敏脂质体(ALTSL)联合靶向治疗荷H22瘤小鼠的协同作用,并探讨其抑瘤作用的机制。方法:以荷H22瘤小鼠的瘤重为指标,评价药物的抑瘤活性。以荷H22瘤小鼠的存活天数计算生命延长率。以乳酸脱氢酶释放法测定NK细胞的杀伤活性。以MTT比色法检测淋巴细胞的转化率。以流式细胞术检测肿瘤细胞的凋亡及p53、Fas、FasL和caspase-3的表达。用RT PCR法测定IL-2mRNA及IL-12mRNA的表达。镜下观察荷H22瘤小鼠肿瘤、心、肝及肾脏组织的病理变化。结果:rhIL2 ALTSL的抑瘤率显著高于单用ALTSL,分别为73.5%和67.0%;ALTSL和rhIL2 ALTSL均可显著延长荷瘤小鼠的存活时间(P<0.05～P<0.01)与对照组和游离阿霉素(FADM)组相比较,ALTSL组NK细胞的杀伤活性显著增加,rhIL2 ALTSL组NK细胞的杀伤活性更高。与FADM组比较,rhIL-2 ALTSL组淋巴细胞的转化率明显提高(P<0.01)。应用ALTSL组和rhIL-2 ALTSL组均可增强脾细胞中IL-2mRNA和IL-12mRNA的表达,但后者的增强作用高于前者。病理切片检查显示,热敏脂质体配合肿瘤局部加热,使肿瘤细胞凝固坏死,联合应用rhIL-2肿瘤组织溶解,细胞破碎,可见大量的淋巴细胞浸润。结论:ALTSL能提高ADM的抑瘤效果,降低ADM心肺的毒性。rhIL-2 ALTSL可诱导肿瘤     

表达CRT-E2融合蛋白肿瘤疫苗诱导特异性抗肿瘤免疫应答

目的:探讨表达钙网蛋白(Calreticulin,CRT)和HPV E2融合蛋白的肿瘤疫苗在小鼠体内诱导的抗肿瘤免疫应答.方法:转染重组质粒得到高表达CRT、E2和CRT-E2融合蛋白的肿瘤细胞,作为肿瘤疫苗隔周两次腹腔注射免疫小鼠,17天后观察成瘤率,检测NK细胞杀伤活性、特异性T细胞增殖能力、CIL活性以及睥淋巴细胞分泌IFN-γ水平,并观察荷瘤小鼠生存期.结果:高表达CRT-E2融合蛋白肿瘤疫苗免疫小鼠后,其成瘤率明显低于其他实验组,NK细胞杀伤活性、特异性T细胞增殖能力、CTL活性和脾淋巴细胞分泌IFN-γ水平均显著高于其它实验组(P＜0.01),生存期也明显延长(P＜0.01).结论:小鼠体内实验显示,表达CRT-E2融合蛋白肿瘤疫苗能够诱导特异性CD8+T细胞免疫应答和NK细胞活性,显著抑制了肿瘤生长.     

体外扩增的Treg细胞抑制NK细胞介导的抗肿瘤免疫

目的研究CD4+CD25+调节性T细胞(regulatory T cells,Tregs)对NK细胞肿瘤杀伤力的影响及Treg细胞介导的抗肿瘤免疫抑制的机制;初步探讨过继输注NK细胞逆转Treg细胞介导的抗肿瘤免疫抑制的作用。方法免疫磁珠分离法(MACS)分离得小鼠脾脏Treg细胞及NK细胞,用流式细胞术检测其纯度。以CD3/CD28单克隆抗体磁珠和重组小鼠白介素2(rm IL-2)联合刺激体外扩增Treg细胞,重组小鼠白介素15(rm IL-15)、rm IL-2以及氢化可的松联合刺激体外扩增NK细胞。将扩增后Treg细胞及NK细胞按不同比例混合淋巴细胞培养,MTT比色法检测NK细胞的杀伤活性。将B16-F10小鼠黑色瘤细胞输注至Balb/c小鼠体内建立肺移植瘤模型[1],将荷瘤小鼠分为4组:A组单独接种B16-F10小鼠黑色瘤细胞;B组接种Treg细胞+B16-F10黑色素瘤细胞;C组接种B16-F10黑色素瘤细胞+NK细胞;D组接种Treg细胞+B16-F10黑色素瘤细胞+NK细胞。MTT比色法测定各实验组小鼠脾脏NK细胞的杀伤活性,并比较不同处理组小鼠肺部肿瘤结节数目。结果体外扩增后的Treg细胞对新鲜分选及扩增后的NK细胞活性均具有明显抑制作用(P0.05),且抑制作用呈剂量依赖关系;A组荷瘤小鼠NK细胞活性低于正常小鼠,且B组荷瘤小鼠NK细胞活性较A组进一步降低(P0.05);D组荷瘤小鼠NK细胞活性高于A组和B组荷瘤小鼠,但仍低于正常小鼠组(P0.05)。B组荷瘤小鼠肺部移植瘤数目(105.33±10.97)较A组明显增多(17±4.58)(P0.01);C组荷瘤小鼠肺部移植瘤数目(2.00±1.00)较A组(17±4.58)明显减少(P=0.037);D组荷瘤小鼠肺移植瘤数目(79.00±8.54)较B组明显降低(105.33±10.97)(P=0.030),但仍高于A组荷瘤小鼠(17±4.58)(P0.001)。结论体内种植肿瘤会抑制机体NK细胞活性;输注体外扩增Treg细胞能够通过抑制NK细胞发挥抗肿瘤免疫抑制;过继输注体外扩增NK细胞能够部分逆转Treg细胞介导的抗肿瘤免疫抑制。     

龙牙楤木多糖抗肿瘤活性及对荷瘤小鼠免疫功能的影响

目的:探讨龙牙楤木多糖(AEPS)抗肿瘤活性及对荷瘤小鼠免疫功能的影响。方法:以S180肉瘤为肿瘤模型,检测龙牙楤木多糖对肿瘤生长的抑制活性;MTT法检测龙牙楤木多糖对S180肉瘤细胞、A549肺癌细胞、SMMC-7721肝癌细胞的体外抑制活性;以其对荷瘤小鼠免疫器官、血液淋巴细胞数量及淋巴细胞增殖影响、巨噬细胞活性和NK细胞杀伤活性来评价AEPS对荷瘤小鼠免疫功能的作用。结果:AEPS对S180肉瘤生长有显著的抑制作用,其中75 mg/(kg.d)剂量组抑瘤率最高达57.68%;AEPS对S180肉瘤细胞、A549肺癌细胞、SMMC-7721肝癌细胞生长的最高抑制率均达60%以上;AEPS显著提高荷瘤小鼠脾脏和胸腺质量以及血液淋巴细胞数量,促进淋巴细胞增殖反应,增加NK细胞杀伤活性和巨噬细胞活性。结论:AEPS有显著的抗肿瘤活性,并能直接作用于肿瘤细胞,抑制肿瘤生长,其抑瘤作用与机体免疫功能的增强有关。     

联合应用IL-2及IL-4基因转染瘤苗对实验性肺转移肿瘤的治疗作用

将IL—2基因转染的高分泌IL—2的B16黑色素瘤细胞株(B2)及IL—4基因转染的高分泌IL—4的B16黑色素瘤细胞株(B4)制备成新型瘤苗,用以治疗实验性肺转移荷瘤小鼠,并辅以低剂量环磷酰胺,结果表明,荷瘤小鼠存活期明显延长;肺部转移结节数明显减少;两种瘤苗联合治疗后的疗效较单独使用明显,当辅以低剂量环磷酰胺时治疗效果更加明显。体内免疫功能检测表明,经两种瘤苗联合治疗的荷瘤小鼠脾细胞NK及CTL杀伤活性升高得更加明显,但对LAK活性及腹腔巨噬细胞杀伤活性无明显协同增强作用;脾细胞经诱导后产生的细胞因子中,IL—2含量有所升高。     

三取代型钛钨硅酸盐体内抑瘤效应的免疫机制探讨

目的:探讨三取代型钛钨硅酸盐(WT)体内抑瘤效应的免疫机制。方法:建立荷H22肝癌小鼠模型,WT连续灌胃10d,取出肿瘤称重测定抑瘤率。用MTT比色法测定荷H22肝癌小鼠淋巴细胞转化的活性及NK细胞的杀伤活性。通过形态学观察和流式细胞仪检测WT诱导BEL-7402细胞的凋亡。结果:WT可显著抑制荷瘤小鼠肿瘤生长(P<0.05),提高荷瘤小鼠淋巴细胞转化的活性及NK细胞的杀伤活性(P<0.05),并诱导肿瘤细胞发生凋亡。结论:WT的抑瘤作用与机体免疫功能的增强有关。     

肿瘤免疫抑制与治疗

肿瘤细胞能产生IL 10、IL 6、TGE2 、PGFβ等多种免疫抑制物质 ,促进Th2细胞及肿瘤细胞增殖 ,抑制Th1、Mφ、CTL、NK细胞的分化与功能 ,引起宿主免疫功能高度抑制。肿瘤细胞Fas基因突变或缺失 ,可逃避CTL的杀伤作用。肿瘤细胞还可表达FasL ,并用以杀伤肿瘤浸润淋巴细胞。因此肿瘤细胞能在宿主体内存活与增殖。用多种细菌组成的联合菌苗 ,与小剂量多种细胞因子及足量抗人IL 10、抗人IL 6抗体 ,PG拮抗剂等 ,配合手术、放疗或化疗协同治疗肿瘤 ,或许能有效地抑制肿瘤发展。     

树突状细胞靶向性DNA疫苗的抗肿瘤免疫效应

目的:构建含OVA-Fc融合基因并对树突状细胞具有靶向性的DNA疫苗,评价其在肿瘤治疗中的作用。方法:构建真核表达载体OVA-Fc-pcDNA3.1,以脂质体转染法将其导入CHO细胞,用流式细胞术和ELISA法检测融合蛋白OVA-Fc的表达。建立E.G7-OVA荷瘤小鼠模型,用51Cr释放实验测定免疫小鼠脾脏细胞毒性T淋巴细胞(CTL)的抗肿瘤活性。通过观察荷瘤小鼠肿瘤的体积和生存期评价该肿瘤疫苗的疗效。结果:酶切鉴定和序列测定证明,真核表达载体OVA-Fc-pcDNA3.1构建正确。用流式细胞术和ELISA法均表明,转染的CHO细胞能表达OVA-Fc融合蛋白。OVA-Fc能激发CTL的杀伤活性,发挥抗肿瘤作用,从而减缓肿瘤的生长,延长荷瘤小鼠的生存期。结论:含OVA-Fc-pcDNA3.1的树突状细胞靶向性DNA疫苗能在体内有效地激发抗瘤免疫应答,为进一步开展临床实验奠定了基础。     

顺铂联合exosomes抗小鼠肝癌效应的实验研究

目的:评价顺铂(DDP)与exosomes联用的抗肿瘤效果,研究其可能机制.方法:采用MTT法检测顺铂对小鼠肝癌H22细胞增殖的影响,用H21源exosomes瘤苗免疫小鼠,3 H-TdR释放法检测exosomes诱导产生的CTL活性及顺铂对CTL杀伤的增敏作用,RT-PCR检测顺铂作用后H22细胞中Fas及exosomes免疫后脾淋巴细胞FasL的mRNA表达水平,Western blot检测顺铂对H22细胞Fas的蛋白表达水平的影响.以小鼠肝癌H22细胞接种BALB/c小鼠建立动物模型,观察顺铂联合exosomes治疗对小鼠生存期的影响.结果:顺铂抑制H22细胞生长呈量效关系;exosomes免疫小鼠可诱导产生针对H22细胞的CTL反应,经2.5 mg/L顺铂预处理24 h的H22细胞对CTL杀伤的敏感性增强(P＜0.05).顺铂在mRNA和蛋白水平,显著增强H22Fas的表达;exosomes免疫小鼠后,脾淋巴细胞FasL表达增加.顺铂联合exosomes组小鼠生存期较单独治疗组及对照组明显延长(P＜0.05).结论:顺铂与exosomes联合治疗有协同抑制肿瘤的作用,产生协同作用的机制与增强CTL活性有关.     

复发性自然流产患者主动免疫治疗前后外周血淋巴细胞Fas/FasL表达水平的研究

目的研究复发性自然流产(RSA)患者外周血淋巴细胞Fas/FasL表达水平,探讨Fas/FasL系统与RSA的发病关系以及主动免疫治疗对RSA患者外周血淋巴细胞Fas/FasL表达水平的影响。方法收集2009年6月至2010年4月在汕头大学医学院附属粤北人民医院妇产科门诊就诊的早孕期RSA患者12例,未孕期RSA患者15例作为研究组,采用荧光标记流式细胞分析技术分别检测主动免疫治疗前后外周血淋巴细胞Fas、FasL表达水平,选择同期正常早孕妇女15例,正常未孕妇女15例作为对照组,比较各组Fas、FasL表达水平的差异。结果 (1)未孕组中,RSA患者外周血NK细胞和CD8+T细胞Fas的表达水平均比正常妇女高,NK细胞FasL表达水平比正常妇女低(P<0.05),CD8+T细胞FasL、CD4+T细胞Fas、FasL的表达水平两组相比无明显差异(P>0.05);(2)早孕组中,RSA患者外周血NK细胞Fas、FasL的表达水平均比正常妇女低,CD8+T细胞Fas表达水平比正常妇女高(P<0.05),CD8+T细胞FasL、CD4+T细胞Fas、FasL的表达水平两组相比则无明显差异(P>0.05);(3)主动免疫治疗后RSA患者(早孕组和未孕组)外周血NK细胞和CD8+T细胞的Fas表达水平均较治疗前下降,FasL表达水平均较治疗前上升,差异有统计学意义(P<0.05),CD4+T细胞Fas、FasL的表达水平与治疗前相比无明显差异(P>0.05)。结论 (1)外周血NK细胞和CD8+T细胞Fas表达升高,FasL表达不足是导致RSA发生的重要免疫学因素之一。(2)主动免疫治疗可能通过改变RSA患者外周血NK细胞和CD8+T细胞的Fas/FasL表达水平,改善细胞凋亡状态而取得疗效。     

NK cell-based immunotherapy for cancer

Natural killer (NK) cells can induce an antigen-independent immune response against malignant cells. A growing number of scientific reports and clinical studies have shown promising anti-tumor effects when using NK cell-based immunotherapy. Currently, various approaches are being used to enhance the number and function of NK cells. One approach uses cytokines to selectively boost both the number as well as the efficacy of anti-tumor functions of NK cells. Another emerging approach focuses on checkpoint inhibitors targeting the NK cell receptor. Furthermore, bi-specific and tri-specific engagers have been developed to enhance the specific immune response by cross-linking specific tumor antigens to effector cells. In addition, NK cell adoptive transfer therapies have shown promising prospects. Among the various sources of adoptive transfer NK cells, allogeneic haploidentical NK cells that have undergone short- or long-term activation or expansion have also demonstrated effective anti-tumor effects with a low rate of rejection and side effects. CAR-NKs, derived from a new type of genetic modification, show enhanced NK cell cytotoxicity, specificity, and targeting. These NK cell-based therapies have exhibited promising results in clinical trials with malignant tumors. In this review, the current progress on NK cell-based therapeutic approaches, NK cell manufacturing techniques and tumor therapy outcomes are discussed.     

血必净对活化诱导T细胞凋亡的调节

目的 观察活化诱导对脾脏T淋巴细胞凋亡、凋亡相关基因mRNA表达及caspase3活性的影响,以及活血化瘀中药的调节作用.方法 提取BALB/c小鼠脾脏T淋巴细胞并培养,以Con A+IL-2诱导T细胞活化凋亡,MTT法检测细胞增殖活性,流式细胞仪检测细胞凋亡率,RT-PCR检测Fas、FasL、Bcl-2、Bax、IL-2 mRNA表达水平,分光光度法测定caspase3酶活性,并观察活血化瘀中药对上述各项指标的影响.结果 活化T淋巴细胞于诱导18h后凋亡率明显增加,于诱导6h时未见FasL、Bax mRNA表达,Fas、Bcl-2 mRNA表达无明显变化;于诱导18 h后Fas、FasL、Bax mRNA表达升高,Bel-2 mRNA表达下降,caspase3活性增高.活血化瘀中药可降低T细胞凋亡,并可分别降低Fas、FasL、Bax mRNA表达,提高Bcl-2 mRNA表达,减轻easpase3酶活性.在活化诱导早期(6 h)促进T淋巴细胞内IL-2 mRNA表达,在晚期(18 h)减少IL-2 mRNA表达.结论 过度活化是脾脏T淋巴细胞异常凋亡的诱发因素,而凋亡的发生与Fas、FasL、Bax、Bcl-2 mRNA表达的改变有关.活血化瘀中药可通过调节IL-2及凋亡相关基因mRNA表达而减轻脾脏T淋巴细胞凋亡,同时可以促进T淋巴细胞的增殖活性.     

Role of interleukin-18 in human natural killer cell is associated with interleukin-2

Human natural killer (NK) cells constitute an important cellular component of innate immunity, capable of killing infected and transformed cells. The proliferation and activation of NK cells are regulated by various cytokines. Interleukin-18 (IL-18) promotes NK cell activation; however, whether the effects of IL-18 on NK cell are associated with other cytokines is still unknown. In this study, we observed that IL-18 induced NK cell apoptosis and inhibited NK cell expansion in the presence of low concentrations of interleukin-2 (IL-2), while high concentrations of IL-2 overcame these effects of IL-18, and high concentrations of IL-2 promoted the stimulatory activity of IL-18 on NK cells. At a low concentration of IL-2, IL-18 induced NK cell apoptosis in part through activation of the FasL/Fas- and TNFα/TNFR-mediated death receptor signaling by enhancing FasL expression and inhibiting c-FLIP_long expression. However, high concentrations of IL-2 strongly blocked IL-18-induced NK cell apoptosis through alleviating IL-18-induced FasL expression and activation of Fas-mediated death signaling and increasing anti-apoptosis molecule (Bcl-X_L). These results reveal that the effects of IL-18 on human NK cell are associated with IL-2 concentration and suggest the importance of IL-2 level in cytokine immunotherapy.     

Interleukin 2-activated large granular lymphocytes: cytotoxic efficiency and mechanism of killing of tumor cell lines

We have compared the effects of interleukin 2 (IL-2) on the proliferative and cytolytic activity of human peripheral blood lymphocytes (PBL) and natural killer (NK) cell-enriched large granular lymphocyte (LGL) subpopulations. Both populations displayed enhanced cytolytic activity against various cell lines following culture with IL-2; the killing capacity and growth of IL-2 activated LGL was, however, superior to that of PBL. Analysis of the mechanisms of action of IL-2 indicated that the percentage of cells binding to tumor targets as well as the frequency of killer cells in both lymphocyte populations was increased after culture with IL-2; however, the LGL displayed 1.5-2.5-fold greater increase in all parameters of cytotoxicity. Additionally, the rate of tumor cell killing and the recycling capacity of LGL were substantially increased (63-76-fold and 4-9-fold, respectively), following IL-2 activation. These data indicate that IL-2-induced potentiation of cytolytic activity is due to an increase in all parameters of the lytic process, and suggest that NK-enriched LGL may be a more powerful antitumor effector population for use in adoptive therapy.     

Combination Therapy Using IL-2 and Anti-CD25 Results in Augmented Natural Killer Cell–Mediated Antitumor Responses

Interleukin (IL)-2 has been extensively examined to promote clinical T and natural killer (NK) cell responses. Regulatory T cells (Tregs) have been shown to regulate many aspects of the immune system, including NK cell–mediated responses. We have demonstrated that in vivo administration of IL-2 led to activation and expansion of both NK cells and immunosuppressive Tregs. Therefore, we attempted to augment NK cell antitumor effects by concurrently depleting Tregs using anti-CD25. Increased NK cell activation by IL-2 was found to be correlated with an increase in classical, short-term NK cell in vitro killing assays regardless of the depletion of Tregs. But when splenocytes of the treated mice were used in long-term tumor outgrowth experiments, we observed that prior depletion of Tregs from IL-2 administration led to improved antitumor effects compared with either treatment alone. Importantly, these in vitro data are correlated with subsequent in vivo survival of leukemia-bearing mice, in which co-treatment of IL-2 with anti-CD25 led to significantly improved survival compared with mice treated with either IL-2 alone or with Treg depletion. Prior depletion of NK1.1⁺ cells, but not of CD8⁺ cells, completely abrogated all antitumor effects mediated by IL-2 and anti-CD25 combination therapy. These findings demonstrate that superior NK cell–mediated antileukemic effects can be achieved with IL-2 administration and concurrent depletion of CD25⁺ cells.