IL—2基因转染的肿瘤细胞增强机体免疫功能的实验研究

目的：探讨小鼠接种腺病毒介导的IL－2基因转移的CT26小鼠结肠腺癌细胞后机体免疫功能的变化（包括CTL、LAK细胞、NK细胞、巨噬细胞的杀伤活性变化）。方法：体外将腺病毒介导的小鼠IL－2基因转染CT26细胞（CT26-mIL-2)，然后将CT26－mIL2细胞接种于小鼠皮下。采用4h乳酸脱氢酸释放法检测荷瘤小鼠CTL、LAK、NK细胞的杀伤活性，MTT法检测巨噬细胞的杀伤活性。结果：接种CT26－mIL－2后第14d，小鼠脾细胞NK活性和诱导后的LAK活性和CTL活性均显著高于对照组（P＜0．01）；小鼠腹腔巨噬细胞数量显著增加，杀伤活性显著增强（P＜0．01）。结论：IL－2基因转染的肿瘤细胞能诱导机体的特异性和非特异性免疫功能参与机体的抗肿瘤作用。     

联合B7-1分子、IL-2及LAK细胞治疗肝癌的实验研究

目的：研究共刺激信号在肿瘤免疫中的作用。方法：构建含人B7-1基因的真核表达载体PRCCMV-B7-1，脂质体介导DNA转移法将人B7-1基因转入人肝癌细胞株SMMC7721，建立新的细胞株SMMC-B7-1，PCR及逆转录PCR（RT-PCR），流式细胞仪检测，四唑卤（MTT）比色试验体外检测白细胞介素-2（IL-2）激活的LAK细胞（LAK-C），对两种肝癌细胞的杀伤活性，结果：PCR，RT-PCR法证实SMMC-B7-1细胞稳定表达B7基因，LAK细胞对SMMC-B7-1细胞的杀伤活性明显高于SMMC7721，结果有统计学意义。结论：B7基因可以体外转染人肝癌细胞，并表达有活性的B7分子，明显增强IL-2激活的LAK细胞的肿瘤杀伤作用。为进一步开展临床应用奠定基础。     

腺病毒介导IL-2基因转染的瘤苗体内抗肿瘤作用

目的 :探讨重组腺病毒介导的 IL- 2基因转染的瘤苗的体内抗肿瘤作用及其免疫学机制。方法 :应用腺病毒介导的鼠 IL- 2基因转染 CT2 6小鼠结肠癌细胞 ,灭活后用作瘤苗治疗荷瘤小鼠 ,观察皮下肿瘤生长及其存活期。采用乳酸脱氢酶释放法检测荷瘤小鼠脾细胞 CTL、L AK、NK细胞的杀伤活性。结果 :鼠 IL- 2基因转染瘤苗治疗能显著抑制荷瘤小鼠皮下肿瘤生长并明显延长其存活期 (P<0 .0 1)。体内免疫功能检测表明 ,鼠 IL- 2基因转染疫苗治疗组小鼠脾细胞 CTL 活性、L AK活性和 NK活性显著高于对照组 (P<0 .0 1)。结论 :腺病毒介导鼠 IL- 2基因转染的瘤苗体内具有较强的抗肿瘤效应 ,其机制可能是提高了荷瘤小鼠特异性和非特异性抗肿瘤免疫反应     

膜TNF-α在小鼠Con A-LAK细胞介导的MHC非限制性杀瘤效应中的作用

本文研究Con A预刺激小鼠LAK细胞(Con A-LAK)的体外杀瘤活性,探讨膜TNF-α在其杀瘤效应中的作用.结果表明.Con A-LAK可杀伤NK敏感的YAC-1、TNF敏感的L929及H-2低/无表达的HCa-F等肿瘤靶细胞;其杀瘤作用主要是直接杀伤,而效应细胞表面配体与靶细胞表面受体相互作用介导的非分泌途径起着重要的作用;Con A-LAK表达膜TNF-α,后者参与杀伤TNF敏感的肿瘤靶细胞,可能是介导MHC非限制性、抗原非特异性杀瘤效应的重要效应分子之一.     

重组痘苗病毒介导的IL-2基因对小鼠Lewis肺癌的体内药效学研究

目的应用重组痘苗病毒介导的IL-2对小鼠Lewis肺癌直接进行局部转染,并对其疗效进行观察和评价.方法本项研究采用缺陷型重组痘苗病毒为载体,经同源重组,筛选出IL-2基因的rW-IL-2,体外转染小鼠Lewis肺癌,对其疗效进行观察.结果短期内即可检出IL-2的表达,并且免疫原性也得到提高.用该载体以in vivo方式原位转染荷瘤小鼠局部;激活了小鼠体内的CTL、LAK及NK细胞,显著抑制了小鼠肿瘤的生长,部分小鼠未能形成肿瘤.结论提示重组痘苗病毒为载体介导的IL-2基因治疗具有良好的前景.     

TNF基因转染的巨噬细胞细胞毒活性变化的研究

将携带ＴＮＦ基因的逆转录病毒上清与小鼠ＭΦ共同孵育，使ＴＮＦ基因导入ＭΦ中，结果发现，ＴＮＦ基因转染的巨噬细胞（ＭΦ─ＴＮＦ＋）分泌ＴＮＦ的水平明显高于正常ＭΦ和转染对照基因的ＭΦ。研究中还发现，ＭΦ─ＴＮＦ＋对Ｐ８１５肿瘤细胞的杀伤率和吞噬力明显高于对照组，用抗ＴＮＦ单抗可明显抑制ＭΦ─ＴＮＦ＋的体外杀伤活性。由此表明，ＭΦ杀伤活性的升高系细胞经基因导入后表达的ＴＮＦ介导的。     

转基因CTL的构建及其生物学特性的研究

目的 :构建TNF α基因转染的CTL ,并对其生物学特性进行研究。方法 :用重组逆转录病毒载体介导将TNF α基因导入CTL ,构建转基因CTL。检测其增殖能力 ,TNF α分泌量、细胞表型 ,观察其对BEL74 0 4的体内、外抗肿瘤活性。结果 :转基因CTL的形态、增殖活性及细胞表型与CTL相似。但具有高效表达TNF α的能力 ,72h表达量为 4 10pg mL。转基因CTL对BEL74 0 4具有较高的体外杀伤作用 ,其杀伤活性与作用时间及效靶细胞比正向相关。转基因CTL对荷瘤裸鼠过继免疫后 ,移植瘤的生成延迟、生长减慢 ,成瘤率降低。结论 :转基因CTL的构建为肿瘤过继免疫治疗提供新型的效应细胞 ,具有进一步研究的价值     

肿瘤生物治疗新方法的研究

本文简述“九五”攻关项目间“肿瘤生物治疗新方法”且经协作攻关主要完成的研究工作有：重组人TNF、IL－2及B7重组腺病毒表达载体的构建及其包装体系的建立：腺病毒介导的人TNF－α基因转染对人肝癌细胞凋亡和MHC－Ⅰ类分子表达的影响;瘤体内／瘤周注射TNF－α重组腺病毒和（或）IL－2T重组腺病毒对肝癌小鼠的治疗作用及其免疫机理研究。粘附LAK细胞的制备、体外扩增、冻存及复苏;转染B7、IL－2、TNF－α基因重组腺病毒的肿瘤细胞及A－LAK的生物学特性研究;人肝癌组织中MAG基因的表达及MAGE基因修饰树突状细胞体外抗肿瘤作用;转基因瘤苗临床应用安全性的初步性的初步检测,这些研究工作的完成为肿瘤基因治疗的临床应用打下基础。     

IL-2基因修饰的细胞毒 T淋巴细胞抗肿瘤效应的研究

目的：了解IL－2基因修饰的细胞毒T淋巴细胞（cytotoxic T lymphocytes,CTL)的增殖和杀伤活性,探索细胞因子基因疗法及被动免疫治疗脑胶质瘤的新途径。方法：用昆明种小鼠的脾细胞体外诱导CTL,用腺病毒载体转染IL－2基因,观察其体外增殖活性和样伤活性,再用G422小鼠胶质母细胞瘤细胞建立肺转移瘤模型,36h后经过继回输,2周后计数肺的肿瘤结节,观察IL－2基因转染的CTL对实验性肺转移瘤的治疗作用。结果：重组腺病毒载体在MOI（multipliciy of infection)为100时,转染率达96．8％,IL－2基因修饰CTL增殖活性、IL－2的分泌（248u)和体外杀伤活性（36．4％）明显增强,对实验性肺转移瘤的治疗作用都显著增强,肺转移结节数（28）显著减少（P＜0．01）。结论：IL－2基因转染的CTL过继回输,可直接杀伤和诱导激活机体抗肿瘤免疫反应,使体内抗肿瘤效果显著增强,有效抑制实验性肺转移瘤的生长,为胶质瘤的过继免疫治疗提供了新的思路和实验依据。     

腺病毒介导的IL—2基因及B7—1基因联合转染G422细胞致瘤原性和免疫原性的变化

目的研究联合细胞因子基因转染的D422胶质母细胞瘤细胞体内致瘤原性和免疫原性的变化,为胶质瘤的免疫基因治疗打下基础.方法IL-2基因和B7-1基因转染的G422细胞1×105皮下和脑内接种,观察肿瘤生长速度和荷瘤小鼠的存活期,2周取脾脏,检测NK、LAK和CTL的杀伤活性.结果IL-2和B7-1基因联合转染的G422细胞,皮下接种后肿瘤生长明显减慢,脑内接种动物存活期明显延长,NK、LAK和CTL的杀伤活性增强.结论IL-2基因和B7-1基因联合转染的G422细胞,致瘤原性下降,免疫原性增强,能有效激活机体特异性与非特异性抗肿瘤免疫反应.     

Augmentation by tumor necrosis factor alpha of the systemic therapeutic effect of lymphokine-activated killer cells in adoptive immunotherapy of murine tumor

The therapeutic effect of a combined modality of lymphokine-activated killer (LAK) cells and tumor necrosis factor alpha (TNF alpha) on MBL-2 tumor in C57BL/6 mice was studied. Murine LAK cells induced from splenocytes by interleukin 2 (IL2) could lyse MBL-2 target cells in vitro. but no enhancement of the LAK activity was found by the treatment of LAK cells with TNF alpha in vitro. However, the treatment of MBL-2 with TNF alpha enhanced the sensitivity to LAK cells. Moreover, administration of TNF alpha to mice bearing solid MBL-2 tumor led to increased tumor vascular permeability within 1 h, and resulted in the enhanced accumulation of systemically transferred LAK cells in tumor tissue. Based on these results, we treated MBL-2-bearing mice with TNF alpha and then with LAK cells 1 h later. No therapeutic effect was observed when tumor-bearing mice were treated with TNF alpha alone or LAK cells plus IL2. However, adoptive immunotherapy using LAK cells and TNF alpha had therapeutic effects, i.e., growth inhibition of tumor nodules and prolongation of survival. These results indicated that appropriately timed pretreatment of tumor-bearing mice with TNF alpha augmented the anti-tumor efficacy of LAK cells.     

Augmented Systemic Immunity in Mice Implanted with Tumor Necrosis Factor-α Gene-transduced Meth-A Cells

Syngeneic BALB/c mice bearing methylcholanthrene-induced fibrosarcoma (Meth-A) cells transduced with a tumor necrosis factor (TNF) gene showed a longer life span and tumor regression as compared with mice carrying TNF-non-producing Meth-A cells. To elucidate the mechanism of the reduced tumorigenicity of TNF-producing Meth-A, we compared systemic immune responses between mice bearing high TNF producer (C5) and unmodified Meth-A cells (M0). The results indicated that the cytotoxic activity of lymphokine-activated killer cells (LAK) induced from spleen cells of mice bearing C5 was higher against both M0 and C5 than that of LAK from mice bearing M0. Also, C5 was more sensitive to LAK induced from spleen cells of C5- and M0- bearing mice than M0. We also found that cytotoxic T lymphocyte from spleen cells of mice transplanted with C5 was more cytotoxic to M0 than that from mice with M0. In addition, the population of Lyt2 (CD8)-positive T cells was higher in freshly isolated spleen cells of mice transplanted with C5 than from mice with M0. Finally, we observed a higher expression of MHC class 1 antigen on C5 than on M0. These observations suggest that the augmented host systemic immunity in mice carrying TNF gene-modified Meth-A cells is one of the mechanisms of the reduced tumorigenicity of C5 and that the increased systemic immunity can be ascribed to the increased immunogenicity of the tumor cells. Thus, the use of TNF gene-modified tumor cells as vaccines appears to be promising for therapeutic and/or prophylactic application.     

Functional interactions of IL2 and TNF in the differentiation of LGL into LAK effectors

We have previously reported on the synergistic effect of IL2 and TNF on the differentiation of LGL into LAK effectors. In the present study, we have further investigated the molecular basis of this synergistic mechanism and examined the role of TNF in the induction of LAK activity. We show that the generation of optimal LAK activity by low doses of IL-2 in the presence of TNF involves the induction of high-affinity IL2 receptors on LGL and occurs without promoting significant proliferation, suggesting a functional activation rather than a proliferative expansion of LAK precursors. Using blocking studies with anti-Tac and with an anti-IL2 (IHII), which specifically inhibits the binding of IL2 to the p75 IL2 receptor component, we also show that both the p55 and the p75 are involved in the increase in TNF binding sites on LGL and the subsequent acquisition of LAK activity. We also demonstrate that the failure of low doses of IL2 to induce LAK activity is related to their incapacity to induce TNF production. Moreover, when specific antibodies against TNF were added to the culture, the differentiation of LGL into LAK effectors by optimal concentrations of IL2 in our system (2.5-5.0 ng/ml) was partially inhibited. This suggests that TNF may be a physiologic mediator in the sequential activation stages of LGL into LAK effectors.     

APOPTOSIS OF TUMOR CELLS IN LECTIN－DEPENDENTLYMPHOKINE－ACTIVATED KILLER CELLMEDIATED CYTOTOXICITY

ＡＰＯＰＴＯＳＩＳＯＦＴＵＭＯＲＣＥＬＬＳＩＮＬＥＣＴＩＮ－ＤＥＰＥＮＤＥＮＴＬＹＭＰＨＯＫＩＮＥ－ＡＣＴＩＶＡＴＥＤＫＩＬＬＥＲＣＥＬＬＭＥＤＩＡＴＥＤＣＹＴＯＴＯＸＩＣＩＴＹＤｏｎｇＨａｉｄｏｎｇ董海东；ＸｉｎｇＲｏｎｇ邢嵘；ＧｕｏＬｉａｎｙｉｎ...     

铂类抗癌药与LILAK细胞联合杀伤人肺腺癌细胞的初步研究

应用ＳＰＣ－Ａ１人肺腺癌细胞系研究了顺铂和上次后的细胞毒效应及其与人外周血ＬＩＬＡＫ细胞的联合效应及机制结果表明：经一定浓度的顺铂或卡铂作用一定时间后，ＳＰＣ－Ａ１细胞可受不同程度的杀伤。经１μｇ／ｍｌ的顺铂处理２４小时，洗去药物后加入ＬＩＬＡＫ细胞，ＳＰＣ－Ａ１细胞被明显杀伤，与未经顺铂处理的对照组相比Ｐ〈０．００１；而卡铂在同样条件下却无此效应。     

Effects of lymphokine-activated killer-cells on melanoma nodules maintained in 3-dimensional culture

Lymphokine activated killer (LAK) cells were cocultivated from 2 to 6 days with WM266 metastatic melanoma cells maintained as nodules in organotypic culture. The LAK cells in suspension were allowed to deposit freely on the nodule surface from where they could infiltrate spontaneously into the nodules. Immunohistochemical studies were done to localize the LAK cells as well as electron microscopical observations for effector/target membrane contacts. Proliferation of the nodules was tested and also that of the LAK cells after coculturing using tritiated thymidine incorporation into DNA. Cell death was determined by arrest of thymidine incorporation and total nodule disintegration. Infiltration rate of LAK cells into the nodules was low: after coculturing 5% of the nodule cells were LAK cells. Although close membrane contacts and cytoplasmic fusions between effector and target cells leading to tumor cell apoptosis were observed, this direct cytolytic process seemed to be too infrequent for the induction of total nodule disintegration at day 6. Therefore, the indirect pathway to cytolysis might be predominant implying, among other cytokines, soluble TNF. On the other hand, LAK cell proliferation diminished strongly after coculturing (down to 11%) but the cytotoxicity was significantly enhanced (18% higher) suggesting an enhancement of differentiation. This might account for the peculiar efficacy of LAK cells on melanomas in vivo and it would be of interest to study this phenomenon further.     

Augmentation of murine lymphokine-activated killer cell induction by a factor produced by Nocardia rubra cell wall skeleton-stimulated T cells

Four-hour exposure of C3H/HeN mouse spleen cells to Nocardia rubra cell wall skeleton (N-CWS) before 4-day culture with a suboptimal dose of human recombinant interleukin 2 (rIL 2) augmented the induction of lymphokine-activated killer (LAK) cell activity, whereas the treatment with N-CWS alone induced no cytotoxicity. In accordance with this, the IL 2 binding activity of spleen cells was augmented by combined stimulation with N-CWS and rIL 2. The augmented cytotoxicity was mediated by Thy-1.2+, Lyt-1.1-, Lyt-2.1- and asialo GM1+ cells. Cell cultures in diffusion chambers revealed that N-CWS-treated spleen cells produced a LAK cell induction-helper factor (LAK-helper factor, LHF) when cultured with rIL 2. The LHF production required Thy-1.2+, Lyt-1.1+, Lyt-2.1+ and asialo GM1- cells, and the coexistence of unstimulated accessory cells was also essential for the LHF production. Cells responding to both LHF and rIL 2 to generate LAK activity were Thy-1.2-, Lyt-1.1-, Lyt-2.1- and asialo GM1+. The culture fluid of spleen cells stimulated with both N-CWS and rIL 2 contained no tumor necrosis factor (TNF) activity, and the additional stimulation with N-CWS caused no production of either IL 2 or interferon (IFN). Murine recombinant interleukin 1 alpha (Mu-rIL 1 alpha) could not replace the augmentative effect of N-CWS on LAK cell induction. These results suggest that in the presence of rIL 2, N-CWS stimulates murine T cells to produce LHF that is probably distinct from IL 1, IL 2, TNF and IFN.     

Up- and down-regulation of human lymphokine (IL-2)-activated killer cell induction by monocytes, depending on their functional state

Studies were made to determine whether freshly isolated monocytes from healthy donors could influence the induction of lymphokine (IL-2)-activated killer (LAK) activity. Highly purified lymphocytes (greater than 99%) and monocytes (greater than 90%) were isolated by counter-flow centrifugal elutriation from peripheral blood. Lymphocytes incubated for 4 days with IL-2 showed significant LAK activity against natural killer (NK) cell-resistant target (Daudi) cells, whereas monocytes treated for 4 days with IL-2 and/or IFN-gamma were not cytotoxic. Under the experimental conditions used, addition of monocytes to the lymphocyte cultures resulted in significant augmentation of the LAK activity, depending on the density of monocytes added. In contrast, monocytes stimulated by lipopolysaccharide (LPS) markedly suppressed LAK activity induced by IL-2, depending on the dose of LPS added. Similar up- and down-regulations of LAK cell induction by monocytes were observed with 4 lines of human lung cancer cells as targets for LAK activity. Although supernatants from untreated monocytes did not increase LAK induction, supernatants from LPS-stimulated monocytes suppressed LAK induction. The regulatory role of monocytes could not be replaced by the addition of exogenous interleukin I (IL-I) or tumor necrosis factor (TNF). Prostaglandin E did not seem to play a regulatory role, since addition of indomethacin did not affect the regulation of LAK cell induction by monocytes. These results clearly indicate that human monocytes may cause up- or down-regulation of the expression of IL-2-induced LAK activity, depending on their functional state.     

MTT法在检测细胞因子与细胞毒效应中的应用

抗癌效应细胞(NK、LAK、CTL、Mφ)细胞毒效应、细胞因子和肿瘤化疗药敏检测目前多采用同位素法,但存在着使用同位素而引起的弊端。寻找一种简便,敏感及安全的检测手段已成为当务之急。我们将MTT比色法用于抗癌效应细胞功能、细胞因子及化疗药敏测定,并与同位素方法进行了对比,结果表明两种方法具有良好的相关性,MTT法与后者相比更为简便、经济、安全和实用。     

Human small-cell lung-cancer cells are cytokine-resistant but NK/LAK-sensitive.

We have studied the effects of 8 cytokines and their combinations on the in vitro growth of 10 human small-cell cancer lines (SCLC). Interferon-alpha and gamma (IFN-alpha and gamma) caused significant but slight growth inhibition over a 7-day incubation period. However, none of the other 6 cytokines, tumor necrosis factor (TNF), lymphotoxin (LT), interleukin-1 beta (IL-1 beta) interleukin-2 (IL-2), transforming growth factor-beta 1 (TGF-beta 1), or granulocyte colony-stimulating factor (G-CSF), modified SCLC cell proliferation. In contrast, all 10 lines were sensitive to lysis by natural killer (NK) and lymphokine-activated killer (LAK) cells. Sensitivity to LAK cells could be increased by pretreatment of SCLC cells with IFN-gamma. As resistance to the cytostatic/cytotoxic activity of some cytokines has been associated with autocrine production of cytokines, we screened the SCLC lines for cytokine mRNAs. Within the limits of detection of the assay we found no expression of TNF, TGF-beta 1, IL-1 beta or IL-6 mRNA in the 10 SCLC lines.