AK细胞及环磷酰胺对肝癌的实验研究

为研究１种新的过继免疫化疗治疗肝癌的方法，采用肝癌细胞株Ｈ２２接种于近交系Ｂａｌｂ／ｃ小鼠皮下，制成肿瘤模型。全胜、肿瘤活化的杀伤细胞（ＡＫ细胞）及环磷酰胺（Ｃｙ）进行治疗，检测小鼠脾淋巴细胞ＮＫ、ＬＡＫ及ＣＴＬ活笥，用流式细胞仪检测Ｌ３Ｔ４ｙｔ－２亚群含量结果表明在过继免疫化疗组小鼠ＬＡＫ及ＣＴＬ活性明显高于其它治疗组（Ｐ〈０．０１），生存期也明显高于其它各治疗组（Ｐ〈０．０１）。该研究过继免疫     

白细胞介素—12基因与HSV—TK基因联合治疗小鼠肝癌的研究

目的　观察白介素１２（ＩＬ１２） 基因与单纯疱疹病毒胸苷激酶（ＨＳＶＴＫ） 基因联合治疗小鼠肝癌的疗效。方法　将ＩＬ１２ 基因和ＨＳＶＴＫ 基因分别转导入小鼠肝癌ＭＭ４５Ｔ－Ｌｉ 细胞,获稳定表达的ＭＭ４５Ｔ－ＬｉＩＬ１２ 和ＭＭ４５Ｔ－ＬｉＴＫ。于Ｂａｌｂｃ 小鼠皮下接种ＭＭ４５Ｔ－Ｌｉ 细胞２ ×１０５ ,待肿瘤长至０－５～１－０ ｃｍ 时,将ＭＭ４５Ｔ．ＬｉＴＫ细胞与经６０ Ｃｏ 照射的ＭＭ４５Ｔ．ＬｉＩＬ１２ 细胞混合,行瘤内注射治疗,于治疗次日,腹腔注射Ｇａｎｃｉｃｌｏｖｉｒ（ＧＣＶ４０ ｍｇ·ｋｇ－ １·ｄ－ １） ,连续注射１０ 天。按同样方法观察对远侧接种的肿瘤的治疗作用,并通过细胞毒Ｔ淋巴细胞（ＣＴＬ） 活性检测及免疫组化染色,探讨其抗肿瘤机制。结果　ＭＭ４５Ｔ．ＬｉＩＬ１２ 与ＨＳＶＴＫＧＣＶ 联合治疗,肿瘤体积显著缩小,生长受到抑制,疗效显著优于单独治疗组（ Ｐ＜ ０．０１） 。有６０％ 小鼠的肿瘤完全消退,且观察２ 个月无肿瘤生长。两者联合治疗,对远侧肿瘤也具有明显的抗肿瘤作用（ Ｐ＜０．０５） 。ＭＭ４５Ｔ．ＬｉＩＬ１２ 与ＨＳＶＴＫＧＣＶ系统联合诱导的小鼠ＣＴＬ明显高于单     

甲氰咪呱对鼠体内IL—2／LAK抗肿瘤作用的影响

为探讨甲氰咪呱（ＣＩＭ）对鼠体内ＩＬ２／ＬＡＫ抗肿瘤作用的影响,将Ｂ１６细胞经尾静脉接种于Ｃ５７ＢＬ／６小鼠,第３ｄ分别应用ＤＨａｎｋｓ液、ＣＩＭ（１０ｍｇ／ｍｌ）＋ＣＩＭ（１μｇ／ｍｌ）诱导的脾细胞,ＩＬ２＋ＩＬ２（５００Ｕ／ｍｌ）诱导的ＬＡＫ细胞,ＣＩＭ（１０ｍｇ／ｍｌ）＋ＩＬ２＋ＣＩＭ（１μｇ／ｍｌ）和ＩＬ２（５００Ｕ／ｍｌ）共同诱导的ＬＡＫ细胞,观察鼠肺转移结节和生存期。结果显示,单用ＣＩＭ并不能减少肺转移结节和延长生存期;ＣＩＭ＋ＩＬ２／ＬＡＫ治疗组与ＩＬ２／ＬＡＫ治疗组相比,可减少肺转移结节（Ｐ＜０．０５）和显著延长生存期（Ｐ＜０．０１）。结果表明,ＣＩＭ能够增强ＩＬ２／ＬＡＫ抗肿瘤作用,可用于治疗肿瘤。     

NK和sIL-2R在肺癌化疗中的临床价值

为了评价肺癌患者化疗后血清ＮＫ细胞活性及ｓＩＬ－２Ｒ水平变化的临床价值，作者采用ＬＤＨ释放法和双抗体夹心ＥＬＩＳＡ法检测４７例肺癌病人和４１例正常对照者的血清ＮＫ细胞活性和ｓＩＬ－２Ｒ水平。结果显示，与正常人相比，肺癌病人血清ｓＩＬ－２Ｒ水平增高（Ｐ＜０．０１），ＮＫ细胞活性降低（Ｐ＜０．０５），且化疗后有效病人血清ｓＩＬ－２Ｒ水平明显低于化疗前（Ｐ＜０．０１）。结果提示血清ＮＫ细胞活性和ｓＩＬ－２Ｒ水平可以作为判断肺癌疗效和预后的指标。     

胃癌患者全胃切除、代胃及人工括约肌重建术后免疫功能的变化

为了研究全胃切除、胃及幽门重建新术式及术后胃癌患者免疫功能的变化，测定了胃癌患者术后０．５ａ、１ａ血液中ＩｇＡ、ＩｇＧ、ＩｇＭ、ＣＤ４、ＣＤ８、ＮＫＬ、Ｌ、ＩＬ－２、ｓＩＬ－２Ｒ、ＩＮＦ－γ水平。新术式术后患者ＩｇＡ、ＩｇＧ、ＩｇＭ、ＣＤ４、ＮＫＬ、Ｌ、ＩＬ－２、ＩＮＦ－γ水平明显高于传统术式组（Ｐ＜０．０１），与非肿瘤手术组相比无显著性差异（Ｐ＞０．０５）；新术式术后患者ＣＤ８、ｓＩＬ－２Ｒ水平明显低于传统术式组（Ｐ＜０．０１），与非肿瘤手术组相比无显著性差异（Ｐ＞０．０５）。结果提示，新术式患者术后免疫功能恢复较快，而传统术式患者术后免疫功能恢复较慢且低下。     

原发性肝癌肝动脉化疗栓塞合并LAK/IL-2灌注治疗的临床Ⅲ期观察

评价肝动脉化疗栓塞合并ＬＡＫ／ＩＬ┐２灌注治疗原发性肝癌的初步疗效。方法不能切除的肝癌患者经肝动脉化疗栓塞后灌注自体ＬＡＫ细胞及ＩＬ┐２，并与单独行肝动脉化疗栓塞的不能切除肝癌患者比较其肿瘤大小，生活质量的变化及毒副反应。结果经肝动脉化疗栓塞合并ＬＡＫ／ＩＬ┐２灌注治疗的２２例肝癌有效率（ＣＲ＋ＰＲ）为１３．６％，包括１例完全缓解和２例部分缓解，而单独化疗栓塞对照组１７例中仅１例显示部分缓解（有效率５．９％）。化疗栓塞＋ＬＡＫ／ＩＬ┐２治疗组与单独化疗栓塞对照组中ＭＲ、ＳＤ、ＰＤ分别为５、１２、１例和１、１１、４例。治疗组中大多数病人生活质量改善或稳定，而对照组中生活质量则无提高。两组病人的毒副反应均较轻而短暂。结论经肝动脉化疗栓塞合并ＬＡＫ／ＩＬ┐２灌注治疗原发性肝癌疗效较优于单独肝动脉化疗栓塞治疗，原发性肝癌更有效的综合治疗方案有待进一步探索     

CD3AK细胞和LAK细胞治疗晚期恶性肿瘤的临床和实验研究

将５１例晚期恶性肿瘤患者（男性２３例，女性２８例）分成两组，其中一组（３１例）以ＣＤ３ＭｃＡｂ（ＣＤ３单克隆抗体）和小剂量ＩＬ－２（５００ｕ／ｍｌ）共同诱导的ＣＤ３ＡＫ细胞治疗，另一组（２０例）输注大剂量ＩＬ－２（１０００ｕ／ｍｌ）诱导的常规ＬＡＫ细胞治疗，以探讨降低ＩＬ－２用量、提高杀伤细胞细胞毒活性的可能性。结果显示ＣＤ３ＡＫ组患者生活质量改善、症状缓解均优于ＬＡＫ组。ＣＤ３ＡＫ组ＰＲ＋ＭＲ率较ＬＡＫ组高２９．０％，Ｓ＋Ｐ率和死亡率分别较ＬＡＫ组低１２．４％和９．６％。同时比较了ＣＤ３ＡＫ细胞与ＬＡＫ细胞的体外增殖和细胞毒活性，结果表明ＣＤ３ＡＫ细胞增殖率高于ＬＡＫ细胞（Ｐ＜０．０１），靶细胞抑制率二者在０．０５水平无显著差异。提示ＣＤ３ＭｃＡｂ在刺激杀伤细胞活性，尤其在提高其增殖能力方面，具有显著的作用，ＣＤ３ＡＫ／ＩＬ－２能更有效地治疗晚期恶性肿瘤。     

鼻咽癌患者T细胞,巨噬细胞及红细胞免疫功能研究

目的　探讨鼻咽癌患者体内多种免疫效应细胞功能的变化规律及其临床意义。方法　分别采用ＡＰＡＡＰ法、斑蝥皮泡法、免疫粘附法及酶免法检测了２９ 例鼻咽癌患者Ｔ细胞亚群、巨噬细胞吞噬率（ＰＲ）及吞噬指数（ＰＩ）、红细胞免疫粘附功能及血清ｓＩＬ２Ｒ水平,并分析其相互关系。结果　鼻咽癌组病人ＣＤ＋３ 细胞、ＣＤ＋４ 细胞、ＣＤ＋４ ／ＣＤ＋８ 比值降低、ＣＤ＋８ 细胞升高,与对照组比较有显著差异（Ｐ＜ ０．０１）;鼻咽癌患者ＰＲ与ＰＩ均显著低于对照组（Ｐ＜ ０．０１）;鼻咽癌组红细胞Ｃ３ｂ 受体花环率（Ｃ３ｂ ＲＲ）显著低于对照组（Ｐ＜ ０．０１）,循环免疫复合物花环率（ＩＣＲ）则显著高于对照组（Ｐ＜ ０．０１）;鼻咽癌患者血清ｓＩＬ２Ｒ明显升高。Ⅲ期以上的鼻咽癌患者与Ⅱ期以下组比较上述免疫指标均有显著差异（Ｐ＜ ０．０１）。鼻咽癌组Ｃ３ｂ ＲＲ与ＰＲ及ＣＤ＋４ ／ＣＤ＋８ ,ＰＲ与ＣＤ＋４ ／ＣＤ＋８ 正相关。ｓＩＬ２Ｒ与Ｃ３ｂＲＲ、ＰＲ及ＣＤ＋４ ／ＣＤ＋８ 均显著相关（Ｐ＜ ０．０５）。结论　鼻咽癌患者多种免疫效应细胞功能下降,并随病情进展,免疫功能进一步下降。对鼻咽癌患者多种免疫效应细胞功能的联合检测有助于了解患者免疫功能的整     

生长抑素 SMS201-995 对小鼠结肠腺癌肝转移瘤的实验研究

目的本研究观察生长抑素衍生物ＳＭＳ２０１┐９９５对ＢＡＬＢ／ｃ小鼠结肠腺癌（ＣＴ２６）肝转移瘤细胞周期的影响，检测血清ＣＥＡ水平的变化，并观察小鼠生存期的改变。方法采用流式细胞术。结果与对照组相比，ＳＭＳ２０１┐９９５治疗组的瘤细胞增殖指数和Ｓ期细胞百分比明显降低（Ｐ＜０．０１），而Ｇ０／Ｇ１期细胞百分比则明显增加（Ｐ＜０．０１）。治疗组血清ＣＥＡ水平较对照组显著降低（Ｐ＜０．０５），生存期明显延长。治疗组细胞增殖指数，Ｓ期和Ｇ０／Ｇ１期细胞百分比与血清ＣＥＡ的变化密切相关（相关系数与Ｐ值分别为：ｒ＝０．６６７７，Ｐ＜０．０５；ｒ＝０．７１７０，Ｐ＜０．０１；ｒ＝－０．６７０３，Ｐ＜０．０５）。结论ＳＭＳ２０１┐９９５对结肠腺癌（ＣＴ２６）肝转移性肿瘤的生长具有一定的抑制作用。     

Bcl-2基因及其家族Bax,Bcl-Xl和Fas/Apo-l,P16的检测在急性白血病中的临床意义

目的：为了解白血病凋亡正、负反馈网络中的问题与临床的关系，研究了抑制凋亡的基因Ｂｃｌ２及其家族Ｂａｘ，ＢｃｌＸｌ以及诱导凋亡的基因Ｆａｓ／Ａｐｏ１，Ｐ１６。方法：采用细胞免疫组化，ＷｅｓｔｅｒｎＢｌｏｔ，以及ＮｏｒｔｈｅｒｎＢｌｏｔ的方法。结果：发现在ＡＭＬ组和ＡＬＬ组，Ｂｃｌ２抗原表达均明显高于正常（Ｐ＜００１），回顾性分析ＡＭＬＣＲ组其明显低于ＮＲ组（Ｐ＜００１）。蛋白印迹ＣＲ组Ｂｃｌ２表达虽然降低，但和ＮＲ组比较无统计学意义（Ｐ＞００５）。Ｂｃｌ２ｍＲＮＡ的表达ＣＲ组明显低于ＮＲ组（Ｐ＜０．０１）。Ｂａｘ的表达在免疫组化中白血病明显低于正常（Ｐ＜００１），但在ＣＲ组与ＮＲ组，免疫组化，蛋白印迹，ＢａｘｍＲＮＡ的表达，均无差异（Ｐ＞００５）。但ＢｃｌＸｌｍＲＮＡ的表达两组间有明显差异（Ｐ＜００１）。Ｆａｓ／Ａｐｏ１的表达为白血病组低于正常（Ｐ＜００１），但在ＣＲ与ＮＲ组中，免疫组化与蛋白印迹分析均无统计差异（Ｐ＞００５）。Ｐ１６的表达为白血病组低于正常组（Ｐ＜００１），但在ＣＲ组与ＮＲ组中无统计学意义（Ｐ＞００５）。结论：Ｂｃｌ２抗原以及Ｂｃｌ２ｍＲＮＡ，Ｂｃｌ     

IL-27基因修饰树突状细胞活化的特异性CTL对人食管癌裸鼠移植瘤生长增殖的影响

研究IL-27基因转染树突状细胞（DC）体内诱导免疫杀伤食管癌细胞的效能及其机制。方法:基因转染的方法建立表达IL-27基因的树突状细胞（DC/IL-27）;构建人食管癌细胞裸鼠移植瘤模型,皮下注射食管癌细胞抗原致敏、IL-27基因修饰DC（DC/IL-27-Ag）活化的特异性CTL后观察荷瘤裸鼠抑瘤率;TUNEL法检测荷瘤裸鼠肿瘤细胞的原位凋亡;流式细胞术检测移植瘤细胞的细胞周期、凋亡率。结果:RT-PCR显示DC/IL-27细胞中有IL-27 p28和EBI3亚基基因表达提示转染成功;免疫接种DC/IL-27-Ag活化的CTL组的抑瘤率为58.28%,明显高于其他组,差异有统计学意义（P<0.01）。TUNEL法检测显示,DC/IL-27-Ag活化的CTL组凋亡率明显高于其他组（P<0.01）,流式细胞术（FCM）显示肿瘤组织内细胞增殖指数为（23.92±1.60）%,显著低于其他组,差异有统计学意义（P<0.01）;细胞凋亡率为（32.78±0.83）%,显著高于其他组,差异有统计学意义（P<0.01）。结论:DC/IL-27-Ag可活化特异性CTL,在裸鼠体内产生了抑制肿瘤生长的作用,显著抑制食管癌细胞增殖、促进其凋亡,为DC应用于食管癌的免疫治疗提供了理论和动物实验依据。      

CIK细胞体内外抗肝癌细胞作用

目的：研究肝癌患者CIK（cytokine-induced killer) 细胞的体外杀伤自体肝癌原代细胞的细胞毒活性以及正常人CIK细胞在裸鼠体内的抗肿瘤作用。方法：分别分离获得肝癌患者和下人的外周血单个核细胞（PBMC）,加入细胞因子,体外诱导成CIK细胞,用流式细胞仪对细胞作动态表型分析,并与正常人的CIK细胞作对比。用^51Cr释放法,测定肝癌患者的CIK细胞体外杀伤自体肿瘤细胞的细胞毒性活性。在Balb/c裸鼠皮下接种肝癌细胞BEL－7402,观察CIK细胞对荷瘤鼠的抑瘤作用,并与LAK、PBMC细胞相对比。结果：肝癌患者的CIK细胞体外增殖力强,至培养28天时达到最大增值倍数300多,表型分析结果表明,CD^3 CD56^ 双阳性细胞得到了大量的扩增,其含量由原来的0．23％上升到第21天的17．8％。体外实验表明,肝癌患者的CIK细胞杀伤自体原代肝癌细胞的细胞毒性活性明显高于自体的PBMC细胞。裸鼠体内实验表明,肝癌患者的CIK细胞能够显著抑制肿瘤的生长,其抑瘤率可达84．7％,高于LAK细胞的52．8％及PBMC的37．1％（P＜0．05和P＜0．01）。结论：CIK细胞具有较强的体内外抗肝癌细胞活性,有可能应用于临床上肝癌的过继性免疫治疗。     

DC 荷载α－GalCer 联合肿瘤特异性 CTL 对小鼠 Heps 肝癌移植瘤生长的影响

目的：探讨树突状细胞（DC）荷载α－半乳糖神经酰胺（α－GalCer）联合肿瘤特异性细胞毒 T 淋巴细胞（CTL）对小鼠 Heps 肝癌移植瘤生长的抑制作用。方法：诱导扩增小鼠骨髓来源的 DC 细胞和 T 淋巴细胞,培养成为具有肿瘤特异性的 CTL,DC 细胞体外荷载α－GalCer。建立 Heps 肝癌移植瘤模型,将36只模型鼠随机分为4组（n ＝9）,分别尾静脉给予生理盐水（对照组）、CTL（CTL 组）、DC 荷载α－GalCer（DC 荷载α－GalCer 组）、DC 细胞荷载α－GalCer ＋CTL（联合治疗组）输注。每隔两天测量移植瘤体积,观察体积变化。于治疗后第14d,处死小鼠,取眼球血及瘤体组织。流式细胞术（FCM）检测外周血 CD4＋、CD8＋ T 细胞比例。免疫组织化学染色观察肿瘤组织中 Bcl －2／Bax 凋亡蛋白的表达。结果：与对照组相比,各治疗组均可抑制肿瘤的生长,差异具有统计学意义（P ＜0．01）;联合治疗组较 DC 荷载α－GalCer 组及 CTL 组肿瘤体积明显减小（P ＜0．05）。联合治疗组小鼠外周血 CD4＋、CD8＋ T 细胞数量较另外三组显著升高（P ＜0．05）;对照组、CTL组、DC 荷载α－GalCer 组小鼠外周血中 CD4＋、CD8＋ T 细胞含量无明显差异（P ＞0．05）。与对照组相比,各治疗组移植瘤内 Bax 阳性细胞数量明显增加（P ＜0．05）,Bcl －2阳性细胞数量明显减少（P ＜0．05）;与 CTL组和α－GalCer 组相比,联合治疗组移植瘤内 Bax 阳性细胞明显增加（P ＜0．05）,Bcl －2阳性细胞明显下降（P ＜0．05）。结论：DC 荷载α－GalCer 与肿瘤特异性 CTL 联合应用能够对小鼠 Heps 肝癌移植瘤具有协同杀伤作用。     

Antitumor efficacy of lymphokine-activated killer cells and recombinant interleukin-2 in vivo: survival benefit and mechanisms of tumor escape in mice undergoing immunotherapy

The studies described in this paper showed that the combination of i.v.-transferred lymphokine-activated killer (LAK) cells and i.p. injections of recombinant interleukin-2 (RIL-2) was highly effective in vivo in reducing established pulmonary metastases of natural killer cell-resistant, MCA-105 sarcoma and B16 melanoma in mice. A 3-day in vitro incubation of normal C57BL/6 splenocytes in medium containing pure RIL-2 generated LAK cells that, when combined with RIL-2, reduced the mean number of established pulmonary micrometastases of the B16 melanoma and of the MCA-105 sarcoma from 179 and 140, respectively (in groups treated with Hanks' balanced salt solution alone), to 12 (P = 0.01) and 6 (P = 0.01), respectively. This combined immunotherapy also consistently resulted in significant prolongation of survival in mice with established, 3-day or 10-day pulmonary metastases of the MCA-105 sarcoma. Mice autopsied at time of death revealed a massive involvement of tumor in the lungs and liver in the group receiving Hanks' balanced salt solution alone compared to a small number of residual large lung or liver metastases in the group receiving LAK cells plus RIL-2. Experiments were designed to test whether variants existed in the original tumor cell inoculum that were resistant to killing by LAK cells and thus could account for the metastases that "escaped" the combined immunotherapy of LAK cells plus RIL-2 in vivo. Metastases of the MCA-105 sarcoma that escaped the combined therapy of LAK cells plus RIL-2 were dissected from the organs of mice upon autopsy and directly tested for susceptibility in vitro to lysis by LAK cells in 4-h and 18-h 51Cr release assays. Target cells derived from the metastases were lysed to an equivalent extent as those prepared from a fresh MCA-105 sarcoma that was growing s.c. In addition, successful reduction of pulmonary metastases established by the i.v. infusion of MCA-105 sarcoma cells obtained from metastases that escaped a prior round of therapy with LAK cells and RIL-2 could be achieved in vivo by the combined immunotherapy as well as by high doses of RIL-2 alone. Culture adapted, natural killer cell-resistant B16 melanoma cells surviving two successive treatments with LAK cells in vitro remained as susceptible to LAK cell lysis as untreated B16 melanoma cells in 18-h 51Cr release assays.(ABSTRACT TRUNCATED AT 400 WORDS)     

Intratumoral injection of OK432 and lymphokine-activated killer activity in peripheral blood of patients with hepatocellular carcinoma

Lymphokine-activated killer (LAK) activity of peripheral blood mononuclear cells (PBMC) from 33 patients with hepatocellular carcinoma was significantly decreased compared with that of healthy volunteers. There was less LAK activity in PBMC from patients with larger tumours (5 cm or more in diameter) than in patients with smaller tumours (under 5 cm in diameter). In 8 out of 20 patients with larger tumours there was none or little LAK activity. Flow cytometry revealed that the percentage of Leu11b+ cells in PBMC was lower in patients than in normal volunteers, and was lowest in patients with larger tumours. 10 patients with hepatocellular carcinoma were treated with intratumoral injection of OK432. LAK activity was enhanced after treatment in 7 cases, and the percentage of Leu11b+ cells was increased. Enhancement of LAK activity in response to OK432 was more significant in patients with smaller rather than larger tumours. Of the 7 high LAK responders, 4 showed 50–100% tumour regression at 6–9 weeks after injection.     

Synergistic Suppressive Effect of Double Transfection of Tumor Necrosis Factor-α and Interleukin 12 Genes on Tumorigenicity of Meth-A Cells

Tumor necrosis factor-α(TNF-α) and interleukin 12 (IL-12), both potent antitumor cytokines, are known to be involved in the host's antitumor immune surveillance in tumor bearers, via different mechanisms. The former enhances the activities of dendritic cells, natural killer/lymphocyteactivated killer (NK/LAK) and cytotoxic T lymphocyte (CTL), while the latter induces Th1-type cellular immunity and enhances the activities of natural killer T (NKT), NK/LAK and CTL. In the present study, in the expectation of synergistic actions of these cytokines in stimulating the host's immune responses, we investigated the feasibility of a cancer vaccine involving double transfection with both genes in a murine model. The expression of major histocompatibility complex (MHC) class I, class II and B7.1 on the surface of the double transfectants was enhanced as revealed by FACS analysis. A significant decrease in tumorigenicity was observed in mice inoculated with the double transfectants. Cytotoxicity assay revealed that the activities of NK/LAK and CTL from spleens of mice bearing the double transfectants were enhanced. The induction of tumor-specific immunity was confirmed by rechallenge with parental Meth-A cells in mice that had rejected the double transfectants. Thus, double transfection of TNF-α and IL-12 genes was considered to bring about synergistic suppressive effects on the tumorigenicity of transfectants through the activation of killer cells by produced cytokines and the enhancement of expression of MHC class I, II and B7.1 molecules.     

Synergistic suppressive effect of double transfection of tumor necrosis factor-alpha and interleukin 12 genes on tumorigenicity of Meth-A cells.

Tumor necrosis factor-alpha (TNF-alpha) and interleukin 12 (IL-12), both potent antitumor cytokines, are known to be involved in the host's antitumor immune surveillance in tumor bearers, via different mechanisms. The former enhances the activities of dendritic cells, natural killer / lymphocyte-activated killer (NK / LAK) and cytotoxic T lymphocyte (CTL), while the latter induces Th1-type cellular immunity and enhances the activities of natural killer T (NKT), NK / LAK and CTL. In the present study, in the expectation of synergistic actions of these cytokines in stimulating the host's immune responses, we investigated the feasibility of a cancer vaccine involving double transfection with both genes in a murine model. The expression of major histocompatibility complex (MHC) class I, class II and B7.1 on the surface of the double transfectants was enhanced as revealed by FACS analysis. A significant decrease in tumorigenicity was observed in mice inoculated with the double transfectants. Cytotoxicity assay revealed that the activities of NK / LAK and CTL from spleens of mice bearing the double transfectants were enhanced. The induction of tumor-specific immunity was confirmed by rechallenge with parental Meth-A cells in mice that had rejected the double transfectants. Thus, double transfection of TNF-alpha and IL-12 genes was considered to bring about synergistic suppressive effects on the tumorigenicity of transfectants through the activation of killer cells by produced cytokines and the enhancement of expression of MHC class I, II and B7.1 molecules.     

Synergistic effect of Nocardia rubra cell wall skeleton and recombinant interleukin 2 for in vivo induction of lymphokine-activated killer cells

C57BL/6 mice inoculated i.p. with 3LL tumor cells were treated by local combination therapy with Nocardia rubra cell wall skeleton (N-CWS) and recombinant interleukin 2 (rIL-2). The combination treatment significantly prolonged their survival and augmented lymphokine-activated killer (LAK) activity of peritoneal cavity lymphocytes (PCL), compared with treatments with rIL-2 alone or N-CWS alone. After in vitro culture of peritoneal exudate mononuclear cells with rIL-2, the nonadherent population derived from N-CWS-injected tumor-bearing mice showed a significantly higher LAK activity than did that population derived from saline solution-injected mice. When N-CWS-induced PCL were cocultured with either N-CWS-induced macrophages or control macrophages in the presence of rIL-2, their LAK activity was higher than that of control PCL. Therefore, it was suggested that N-CWS-induced PCL themselves have a more potent ability as precursors of LAK cells. Phenotypic analysis on PCL populations revealed that N-CWS-induced PCL contained increased proportions of CD3+CD4-CD8- cells and asialo GM-1+ cells compared with control PCL. These results suggest that N-CWS selectively accumulates potent LAK precursors, namely, CD3+CD4-CD8- T-cells and asialo GM-1+ natural killer cells, at the injection site and that LAK cells are efficiently induced by subsequent administration of rIL-2.     

缺硒和补充硒对小鼠肿瘤免疫反应的影响

DBA/2 mice were fed for 16 weeks with Torula yeast-based synthetic diet containing various concentrations of selenium (Se). At 13th week, the mice were immunized with syngenetic L5178 Y lymphoma cells and their specific and non-specific tumor immune responses were examined 3 weeks after immunization. The results indicated that in mice fed with a diet containing 0.007 ppm Se, the serum Se level was extremely low (0.02 micrograms/ml). These Se-deficient mice were unable to elicit normal tumor-specific immune responses. Both the specific proliferation of T cells in MLTC and tumoricidal activity of CTL were very much depressed. In addition, these mice also showed impaired NK and LAK cell activity. The effects of Se supplementation varied depending on the amount of Se given. When 0.170 ppm Se was added to the low Se diet, all the immune parameters examined were restored to the normal level. When 0.567 ppm Se was added, however, the tumor immune responses remained as low as those in Se-deficient mice. This study implies that the prevalence of primary hepatocellular carcinoma in areas where Se is deficient has a profound immunological basis. Se supplementation is obviously indicated for cancer prevention in these areas but the amount of Se supplied is crucial.     

The Induction of Enhanced Antitumor Effect against a Nonimmunogenic Tumor by Highly Immunogenic Variants Obtained by Mutagen Treatment

Nonimmunogenic 1767-3 fibrosarcoma was treated with the mutagen N-methyl-N'-nitro-N-nitrosoguanidine, and stable variant cell clones (M-clones) were obtained that were able to elicit an immunological rejection response in syngenic C3H mice. Mice immunized with some M-clones were protected against a challenge from the original nonimmunogenic fibrosarcoma. Furthermore, when spleen cells of immunized syngenic mice were restimulated in vitro with M-clones, cytotoxic T lymphocytes (CTL) were obtained that were able to lyse not only M-clones but also the original nonimmunogenic tumor. These in vivo and in vitro results demonstrate the immunogenicity of M-clones and the existence of a singular antigenic specificity between the original nonimmunogenic tumor and M-clones. For the purpose of application of this mutagen treatment to cancer therapy, we combined it with lymphokine-activated killer (LAK) adoptive immunotherapy (AIT). With interleukin 2 and in vitro stimulation with highly immunogenic variant clones, we tried to induce transfer cells that had not only nonspecific LAK cells but also CTL with specific immunity against the original nonimmunogenic tumor. Successful results were obtained in the LAK AIT models. These findings indicate that an immunotherapy of human cancers that are thought to be weakly or nonimmunogenic may be possible by the application of this approach to LAK AIT.