Immunotherapy for lung metastases of murine renal cell carcinoma: synergy between radiation and cytokine-producing tumor vaccines.

We investigated the combination therapy of local radiation of lung metastasis and vaccination with autologous tumor cells that produced interleukin (IL)-2, interferon-gamma (IFN-gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF) using the mouse Renca pulmonary metastasis model. Wild-type Renca (W/Renca) were transfected with pEF-BOS vector incorporating cDNAs for IL-2, IFN-gamma, or GM-CSF to express these cytokines. W/Renca, IL-2-producing Renca (Renca/IL-2), and IFN-gamma-producing Renca (Renca/IFN-gamma) produced subcutaneous tumor at the injection site in eight of eight, one of eight, and two of eight mice, respectively. No tumors were found in the GM-CSF-producing Renca (Renca/GM-CSF) group (zero of eight). Renca/IFN-gamma produced subcutaneous (s.c.) tumors in all Balb/c nude mice, but Renca/IL-2 and Renca/GM-CSF did not. To test the elicitation of antitumor activity, Balb/c mice were injected intravenously with 1 x 10(5) W/Renca on day 0, vaccinated, s.c., with 1 x 10(6) cells each of 5,000 rad preirradiated Renca/IL-2, Renca/IFN-gamma, and Renca/GM-CSF or 3 x 10(6) cells of preirradiated W/Renca on days 1, 7, and 14, and radiated with 300 rad to both lungs on day 5. The animals were killed on day 21 and tumor nodules in the lungs were enumerated. Neither local irradiation alone nor the combination of lung radiation and multiple vaccination with irradiated W/Renca significantly reduced the number of lung tumors. In contrast, the combination of lung radiation and the multiple vaccinations with cytokine-producing Renca cells significantly reduced the number of lung tumors. This regimen was more effective than the multiple vaccinations with cytokine-producing Renca cells alone. These studies demonstrate the efficacy of vaccination with autologous tumor cells expressing these cytokines and sensitization of the tumor target with radiation.     

Gene therapy with autologous, interleukin 2-secreting tumor cells in patients with malignant melanoma.

We vaccinated metastatic melanoma patients with irradiated, autologous melanoma cells genetically engineered to secrete interleukin 2 (IL-2) to investigate whether an anti-tumor immune response would be induced. Melanoma cell cultures were established from surgical specimens and were engineered to secrete IL-2 by infection with recombinant retrovirus. Twelve patients were vaccinated subcutaneously one, two, or three times with approximately 10(7) irradiated, autologous, IL-2-secreting tumor cells. Treatment was well tolerated, with local reactions at 11 of 24 injection sites and minor systemic symptoms of fever and headache after 6 injections. One patient developed anti-tumor DTH after the first vaccination and showed an increased response after the second vaccination. Anti-autologous tumor CTLs could be detected prevaccination in the peripheral blood of seven patients and their activity increased after vaccination in four patients. No UICC-defined clinical responses were seen, but three patients had stable disease for 7-15 months, one of whom has not yet progressed (15+ months). Thus, patient vaccination with autologous, genetically engineered tumor cells is feasible and safe. Anti-tumor DTH and CTLs can be induced in some patients with such a vaccine.     

Inhibition of lung metastases of murine renal cell carcinoma by the combination of radiation and interferon-alpha-producing tumor cell vaccine

We have previously demonstrated in a murine lung metastasis model that local sublethal radiation of tumors can synergistically enhance their sensitivity to immunotherapy with either systemic high-dose interleukin-2 (IL-2) or vaccination with autologous tumor cells expressing IL-2, interferon (IFN)-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF). Host antitumor activity was mediated in large part by natural killer cells, which can be activated by IFN-alpha. In the present study, we used this lung metastasis model to investigate the efficacy of combined therapy with local tumor radiation and vaccination with IFN-alpha-secreting tumor cells (Renca/IFN-alpha). The in vitro and in vivo growth rates of Renca/IFN-alpha cells were significantly reduced relative to normal controls. Subcutaneous vaccination with Renca/IFN-alpha or selective X-irradiation of the left lung (300 rad) reduced the number of lung tumors by 40% and 27%, respectively. The combination of lung irradiation plus vaccination reduced the number of lung metastases by 60%, and the net tumor volume by 95%. The reductions in tumor volume in both irradiated and non-irradiated lungs were comparable. These results indicate that host antitumor response to subcutaneous vaccination with Renca/IFN-alpha was systemic, and was significantly enhanced by radiation of tumor-bearing lungs. A regimen based on enhancement of IFN-alpha immunotherapy by local tumor radiation may be useful in the treatment of metastatic renal cell carcinoma.     

CCL3/MIP-1alpha is a potent immunostimulator when coexpressed with interleukin-2 or granulocyte-macrophage colony-stimulating factor in a leukemia/lymphoma vaccine

Chemokines orchestrate trafficking of immune effector cells during inflammation. Here we demonstrate that chemokines also serve to potentiate effector cell-mediated antineoplastic immune responses in vaccination strategies. As a critical mediator of inflammation, macrophage inflammatory protein 1alpha (CCL3/MIP-1alpha) attracts and stimulates both antigen-presenting and cytotoxic cells. In the A20 leukemia/lymphoma vaccine model, we explored the efficacy of MIP-1alpha in combination with interleukin-2 (IL-2) or granulocyte-macrophage colony-stimulating factor (GM-CSF). After subcutaneous injection of the MIP-1alpha + IL-2 or MIP-1alpha + GM-CSF combination vaccine, focal but pronounced infiltrates of CD4+ and CD8+ T cells were observed at the vaccination sites. In mice with preestablished leukemia/lymphoma, survival is significantly improved in animals treated with MIP-1alpha + GM-CSF- and MIP-1alpha + IL-2-secreting vaccines. Protection is superior in the MIP-1alpha + GM-CSF group, with the effects of MIP-1alpha and GM-CSF being synergistic. In contrast, suppression of lymphoblast proliferation by single-immunogen vaccines secreting MIP-1alpha, GM-CSF, or IL-2 alone does not translate to improved survival. The systemic protective effects afforded by the MIP-1alpha + IL-2 or MIP-1alpha + GM-CSF combination are mediated by different effector cell populations. In the MIP-1alpha + IL-2 group, antineoplastic defense is mediated by CD8+ T and NK cells, whereas in the MIP-1alpha + GM-CSF group CD4+ T cells are involved in addition to CD8+ cytotoxic T cells, underscoring that T cell help is critical for long-term protection. Thus combination of MIP-1alpha with different cytokines recruits different sets of effector cells into a potent antineoplastic immune response.     

白细胞介素6基因转染的白血病细胞克隆株的建立及其生物学特性的观察

作者将人白细胞介素６（ＩＬ－６）基因转染至ＦＢＬ－３红白血病细胞，建立了高分泌ＩＬ６的ＦＢＬ－３细胞克隆株，并观察了其生物学特性。采用磷酸钙ＤＮＡ共沉淀法将ＩＬ－６表达载体ＢＣＭＧＮｅｏ－ＩＬ－６转移至ＦＢＬ－３细胞中，通过Ｇ４ｌ８抗性筛选、有限稀释法和上清中ＩＬ－６活性的测定，从多株阳性克隆中筛选到一株高分泌ＩＬ－６（２２５．６Ｕ／ｍｌ）的克隆株。体外观察表明，ＩＬ－６基因转染的ＦＢＬ－３细胞体外生长能力、集落形成能力均减弱，且其生长抑制程度与分泌ＩＬ－６水平呈正相关。给小鼠皮下接种后肿瘤结节形成率降低，生长速度减慢，荷瘤小鼠存活期延长。以上结果表明，ＩＬ－６基因转染的ＦＢＬ－３细胞致瘤性下降，这为将该细胞制备成新型瘤苗治疗白血病打下了基础。     

Combination of CD80 and granulocyte-macrophage colony-stimulating factor coexpression by a leukemia cell vaccine: preclinical studies in a murine model recapitulating Philadelphia chromosome-positive acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is a highly aggressive malignancy caused by the bcr-abl translocation oncogene. To explore alternative treatments for Ph+ ALL we tested gene-modified cell vaccines in the BALB/c-derived BM185 leukemia model. We compared the efficacy of BM185 cell vaccine expressing CD80 alone or in combination with IL-2 or GM-CSF. Mice injected with viable BM185 leukemia cells modified to express CD80 and GM-CSF (BM185/CD80+GM-CSF) showed the highest leukemia rejection rates. Cell vaccines consisting of irradiated BM185/CD80+GM-CSF cells administered subcutaneously stimulated a potent cytotoxic T lymphocyte (CTL) response against parental BM185. Histological examination of the vaccination site showed a large concentration of immune cells. Administration of the BM185/CD80+GM-CSF cell vaccine before intravenous challenge with parental cells caused strong inhibition of leukemia development. Vaccination after subcutaneous challenge with BM185 cells caused efficient elimination of leukemia promoting 40-60% long-term survival rates. The immunization efficacy of the BM185/CD80+ GM-CSF cell vaccine was directly correlated with the percentage of cells expressing the transgenes. In all, this preclinical study shows that leukemia cell vaccines coexpressing CD80 and GM-CSF can potentially be explored for immunotherapy in Ph+ ALL patients.     

Augmentation of local antitumor immunity in the liver by tumor vaccine modified to secrete murine interleukin 12.

Minimal residual lesions have been a major problem in surgical management of cancer. We transfected M5076 with murine IL-12 gene by a retroviral vector, established a stable transfectant secreting IL-12 and investigated its antitumor effects on a spontaneous liver metastasis murine model of M5076 reticulum cell sarcoma. Subcutaneous vaccination of the irradiated transfectant into the remote skin following the amputation of the tumor-bearing limb improved survival when compared with the vaccination of irradiated parental cells (control). Cytotoxic activities against parental M5076 were significantly stronger in the hepatic lymphocytes from the mice vaccinated with the IL-12 transfectant than those from the control. IFN-gamma production of hepatic lymphocytes when they were cocultured with the parental cells was significantly augmented in mice vaccinated with the IL-12 transfectant compared with the control. On the other hand, both cytotoxic activity and IFN-gamma production of spleen cells in the M5076-vaccinated and transfectant-vaccinated mice were at similar levels. Immunophenotypic analysis revealed the selective increase of CD3+NK1+ population in the liver from the transfectant-vaccinated mice. These results suggest that tumor vaccines genetically modified to secrete IL-12 continuously at a relatively low level preferentially augment local antitumor activity in the liver rather than systemic immune responses. This strategy warrants further investigation as an adjuvant modality in the management of postoperative residual tumors.     

Vaccination of melanoma patients with an allogeneic, genetically modified interleukin 2-producing melanoma cell line

Thirty-three metastatic melanoma patients were vaccinated according to a phase I-II study with an allogeneic melanoma cell line that was genetically modified by transfection with a plasmid containing the gene encoding human interleukin 2 (IL-2). The cell line expresses the major melanoma-associated antigens and the HLA class I alleles HLA-A1, -A2, -B8, and Cw7. All patients shared one or more HLA class I alleles with this cell line vaccine. Patients were immunized by three vaccinations, each consisting of 60 x 106 irradiated (100 Gy) melanoma cells (secreting 120 ng of IL-2/10(6) cells/24 hr) administered subcutaneously at weekly intervals for 3 consecutive weeks. Side effects of treatment consisted of swelling of locoregional lymph nodes and induration at the site of injection, i.e., a delayed-type hypersensitivity (DTH) reaction. In three patients, vaccination induced inflammatory responses in distant metastases containing necrosis or apoptosis along with T cell infiltration. Apoptosis occurred only in Bcl-2-negative areas, not in Bcl-2-expressing parts of the metastases. Two other patients experienced complete or partial regression of subcutaneous metastases. Seven patients had protracted stabilization (4 to >46 months) of soft tissue metastases, including one patient who developed vitiligo after vaccination. Immune responses to the vaccine could be detected in 67% of the 27 patients measured. Vaccination was shown to induce a variable change in the number of anti-vaccine cytotoxic T lymphocytes (CTLs) in peripheral blood, which did not correlate with response to treatment. However, in two of five patients the frequency of anti-autologous tumor CTLs measured was significantly higher than before vaccination. This study demonstrates the feasibility, safety, and therapeutic potential of vaccination of humans with allogeneic, gene-modified tumor cells, and that frequencies of vaccine-specific CTLs among patient lymphocytes can be determined by using a modified limited dilution analysis (LDA).     

Cytokine depot formulations as adjuvants for tumor vaccines. I. Liposome-encapsulated IL-2 as a depot formulation

In an attempt to mimic cytokine gene-transfected tumor cells and to develop an alternative approach to cancer immunotherapy, the authors vaccinated mice with mixtures of inactivated tumor cells and cytokine-containing depots. The RenCa mouse renal carcinoma and the B16 mouse melanoma were used as animal tumor models, with interleukin-2 (IL-2) as a cytokine and liposomes as a depot form. The results obtained show that vaccines consisting of mixtures of irradiated tumor cells and cytokine-containing liposomes can be used as highly effective tumor vaccines. These vaccines are very easy to prepare and, in contrast to vaccines consisting of cytokine gene transfected tumor cells, their composition (cell dosage, cytokine dosage) can be easily varied. Vaccination efficiency depended on (a) on the immunogenicity of the tumor cells: RenCa tumor cells are more immunogenic than B16 melanoma cells; (b) vaccination frequency: a single vaccination with irradiated tumor cells and 10 micrograms of IL-2 in liposome-encapsulated form was sufficient to induce lasting protective immunity against the RenCa tumor, whereas several (four to six) vaccinations in weekly intervals were needed to obtain a similar degree of protective immunity to the B16 melanoma; and (c) the dose of the cytokine encapsulated in the admixed liposome depots: immunity to the tumors could be induced only within a narrow cytokine-dose range ("IL-2-dose window"). The results obtained indicate that, because of the easiness of preparation and handling, vaccine formulations consisting of irradiated tumor cells and IL-2 in depot formulations are candidates for tumor vaccines for the treatment of tumor patients.     

The protocol of clinical trial and basic experiments for esophageal cancer using gene transduction

We examined whether antitumor effect could be produced by retrovirally expressed interleukin-2(IL-2) gene, glanulocyte macrophage-colony stimulating factor(GM-CSF) gene, herpes simplex virus-thymidine kinase(HSV-tk) gene and p53 gene in human esophageal cancer cells using nude mice. Loss of tumorigenicity of IL-2 or GM-CSF producing cancer cells were observed. The antitumor effect was also evidenced by the injection of these cells into established tumors of wild-type cells. In suicide gene therapy on esophageal cancer, the growth suppression of esophageal cancer cells transducing HSV-tk gene tumors in nude mice induced by ganciclovir treatment and all the tumors disappeared. The wild-type p53 transduced tumor cells became markedly susceptible to irradiation and anticancer agents. Administration of cisplatine noticeably suppressed the growth of p53 transduced tumors inoculated in nude mice. We established the clinical protocol of gene therapy for esophageal cancer using wild-type p53 gene with adenovirus vector. In this autumn we are going to start this clinical trial.     

多发性骨髓瘤基因修饰瘤苗诱导体内抗肿瘤反应的实验研究

本研究目的是评价NOD／SCID小鼠皮下移植瘤模型对多发性骨髓瘤基因修饰瘤苗引发体内抗肿瘤反应的效果。首先给NOD／SCID小鼠腹腔注射人外周血淋巴细胞以在其体内重建人的免疫系统，然后皮下接种γ-射线灭活的基因修饰骨髓瘤细胞sko-007（表达绿色荧光蛋白或者p53、GM—CSF和B7-1基因），以PBS作为对照，最后植入活sko-007细胞进行攻击。结果发现，与对照组相比接种感染腺病毒Ad—p53／GM—CSF／B7-1的sko-007细胞可以明显抑制移植瘤生长，病理分析显示移植瘤纤维组织增生伴弥漫性坏死增多，血管增生显著。免疫组织化学染色显示瘤灶内有人T淋巴细胞浸润。结论：p53、GM—CSF和B7-1基因修饰的骨髓瘤细胞能够诱导产生抗肿瘤免疫反应，有可能用于人类多发性骨髓瘤的免疫治疗。     

基因工程肿瘤细胞融合疫苗诱导Th1应答抗肿瘤

目的　探讨基因工程肿瘤细胞融合疫苗的抗肿瘤作用。方法　将鼠源性IL 12 (mIL 12 )基因转染J5 5 8细胞制备工程瘤细胞 ,再与树突状细胞进行融合后免疫BALB c小鼠 ,14d后再以不同剂量的瘤细胞攻击小鼠以观察其保护效力。结果　制备的工程瘤细胞J5 5 8经测试其培养上清中mIL 12表达量为 (870± 6 0 )pg·(10 5细胞 ) - 1 ·ml- 1 ;与树突状细胞体外融合后 ,镜下测得细胞融合率约为 30 % ;收集免疫小鼠腹股沟及月国窝淋巴结细胞与肿瘤细胞共培养 ,其上清IFN γ含量较对照组高 ;体内、外特异性抗肿瘤实验均显示该型瘤苗具有良好的抗瘤作用。结论　免疫小鼠体内诱导Th1应答 ,其明显的抗肿瘤功效为临床应用提供了可能性     

Helper virus-free herpes simplex virus type 1 amplicon vectors for granulocyte-macrophage colony-stimulating factor-enhanced vaccination therapy for experimental glioma

Subcutaneous vaccination therapy with glioma cells, which are retrovirally transduced to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF), has previously proven effective in C57BL/6 mice harboring intracerebral GL261 gliomas. However, clinical ex vivo gene therapy for human gliomas would be difficult, as transgene delivery via retroviral vectors occurs only in dividing cells and ex vivo glioma cells have a low growth fraction. To circumvent this problem, a helper virus-free herpes simplex virus type 1 (HSV-1) amplicon vector was used. When primary cultures of human glioblastoma cells were infected with HSV-1 amplicon vectors at an MOI of 1, more than 90% of both dividing and nondividing cells were transduced. When cells were infected with an amplicon vector, HSVGM, bearing the GM-CSF cDNA in the presence of Polybrene, GM-CSF secretion into the medium during the first 24 hr after infection was 1026 ng/10(6) cells, whereas mock-infected cells did not secrete detectable GM-CSF. Subcutaneous vaccination of C57BL/6 mice with 5 x 10(5) irradiated HSVGM-transduced GL261 cells 7 days prior to intracerebral implantation of 10(6) wild-type GL261 cells yielded 60% long-term survivors (>80 days), similar to the 50% long-term survivors obtained by vaccination with retrovirally GM-CSF-transduced GL261 cells. In contrast, animals vaccinated with the same number of nontranduced GL261 cells or with GL261 cells infected with helper virus-free packaged HSV-1 amplicon vectors carrying no transgene showed only 10% long-term survivors. In conclusion, helper virus-free HSV-1 amplicon vectors appear to be effective for cytokine-enhanced vaccination therapy of glioma, with the advantages that both dividing and nondividing tumor cells can be infected, no viral proteins are expressed, and these vectors are safe and compatible with clinical use.     

Combination of interleukin 12 and interferon alpha gene therapy induces a synergistic antitumor response against colon and renal cell carcinoma

The antitumor effect and mechanism of action of IL-12 gene therapy combined with IFN-alpha gene therapy were investigated in tumor-bearing mice using renal and colon carcinoma models, Renca and CT26, respectively. Tumors were treated with murine IL-12 plasmid alone or in combination with IFN-alpha plasmid formulated with a polymeric interactive noncondensing (PINC) gene delivery system. Intratumoral injection of IL-12 DNA/polyvinyl pyrrolidone (PVP) alone induced rejection of 58 and 17% of Renca and CT26 tumors, respectively, whereas 25% (Renca) and 0% (CT26) rejection was observed in mice treated with IFN-alpha plasmid/PVP. Combination gene therapy of formulated plasmids, IL-12 with IFN-alpha, synergistically increased the antitumor response against Renca (100% tumor rejection) and CT26 (50%). In vivo depletion of leukocyte subsets indicated that CD8(+) T and NK cells were the primary effectors of the antitumor response induced by the combined cytokine gene therapy. Moreover, mice that rejected the primary tumors after combined treatment with IL-12 and IFN-alpha plasmid formulation developed protective immunity against a subsequent tumor challenge. Analysis of tumor-infiltrating leukocytes from mice treated with the combined IL-12 and IFN-alpha gene therapy showed upregulation of CD40 molecules on antigen-presenting cells (Mac-1(hi) cells). Finally, levels of mRNA for the chemokines IP-10 and TCA-3 were higher in tumors treated with the combination of cytokine plasmids than in tumors treated with either cytokine gene alone. These data provide evidence that IL12 gene therapy combined with IFN-alpha gene therapy synergistically induces regression of established tumors and may represent a novel therapeutic strategy for cancer treatment.     

Novel membrane-bound GM-CSF vaccines for the treatment of cancer: generation and evaluation of mbGM-CSF mouse B16F10 melanoma cell vaccine

Cancer vaccines composed of tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) are currently being clinically evaluated. To enhance the immunogenicity of GM-CSF-secreting tumor cell vaccines, a novel approach expressing GM-CSF as a membrane-bound form (mbGM-CSF) on the tumor cell surface was investigated. The intent was to enhance antigen presentation by increasing interactions between the tumor cell lines in the vaccine and GM-CSF receptor positive antigen presenting cells (APC), notably the patient's Langerhans cells residing within the intradermal injection site. B16.F10 cells engineered to express either membrane-bound or secreted GM-CSF were compared in the B16.F10 mouse melanoma model. We observed that mbGM-CSF on the tumor cell surface retarded growth and induced protective immunity to subsequent wild-type tumor challenge more effectively than tumor cells secreting GM-CSF. Vaccination with irradiated mbGM-CSF B16.F10 also provided strong protection from wild-type tumor challenge, improved therapeutic effects against established tumors, and retarded lung metastases. These results demonstrate that mbGM-CSF B16.F10 cells can induce strong systemic immunity that protects against and therapeutically treats B16.F10 melanoma more effectively than analogous vaccines containing only secreted GM-CSF. These data warrant further development and clinical testing of mbGM-CSF tumor cell vaccines.     

Cytotoxic T lymphocyte response against non-immunoselected tumor antigens predicts the outcome of gene therapy with IL-12-transduced tumor cell vaccine.

The colon adenocarcinoma C26, carrying two endogenous tumor-associated antigens (TAA) recognized by CTL, has been transduced with the gene coding for the human folate receptor alpha (FR alpha) as an additional antigen in order to study the efficacy of vaccination against a tumor expressing multiple antigens. A dicistronic vector was used to transduce the IL-12 genes to create C26/IL-12/FR alpha that has been used as a cellular vaccine to treat mice bearing lung metastases of C26/FR alpha. After vaccination mice were partially splenectomized and splenic lymphocytes frozen and used retrospectively to study in vitro CD8 T cell response related to the treatment outcome. Vaccination cured 50% of mice and the effect was CD8 T cell dependent. Mice either cured (responders) or not cured (nonresponders) by vaccination developed tumor-specific CTL. However, analysis of CTL specificity and pCTL frequencies revealed that responders had a predominant CTL activity against endogenous C26-related tumor antigens, whereas nonresponders had CTL that recognized preferentially the FR alpha antigen. CD8 from responder mice were characterized to release high levels of granulocyte-macrophage (GM)-CSF upon antigen stimulation. Tumors obtained from mice that died despite vaccination lost expression of the FR alpha transgene but maintained expression of endogenous C26 antigens. Immunoselection against FR alpha antigen was not observed in tumors from non-vaccinated controls and from CD8-depleted vaccinated mice. Down-regulation of FR alpha antigen expression was due, at least in part, to methylation of retroviral vector long terminal repeat promoter since FR alpha expression was partially restored, ex vivo, by treatment with 5-aza-2'-deoxy-cytidine (aza). These results indicate that CD8 T cell-mediated immunoselection and production of GM-CSF are determining factors for the efficacy of tumor vaccines.     

IL—2基因修饰增强白血病抗原冲击的树突状细胞诱导的抗肿瘤？…

目的 研究腺病毒介导的白细胞介素（ＩＬ）２基因修饰能否使抗原冲击的树突状细胞（ＤＣ）在体内诱导出更强的抗肿瘤免疫反应。方法 用小鼠粒－巨噬细胞击落刺激因子（ｍＧＭ－ＣＳＦ）和ｍＩＬ－４扩增上鼠骨髓ＤＣ在ＦＢＬ－３红白血病细胞冻融抗原冲击的同时转染ＩＬ－２腺病毒。观察其体外分泌ＩＬ－２的水平,刺激Ｔ细胞增殖的能力,其体内皮下免疫后小鼠引流淋巴结细胞数和组分的变化以及主艉地产生细胞毒性Ｔ淋巴细胞（ＣＴ     

Oral Vaccination With Adeno-associated Virus Vectors Expressing the Neu Oncogene Inhibits the Growth of Murine Breast Cancer

Recombinant adeno-associated viruses (AAV) have been used for therapeutic gene transfer. These vectors offer a number of advantages including resistance to the effects of pH, a broad cellular tropism, efficient gene transfer, persistence of gene expression, and little toxicity. AAV vectors; however, at high doses can induce humoral and cellular immune responses. While potentially problematic for replacement gene therapy, this effect may be advantageous for antitumor vaccination. We examined the activity of an oral and intramuscular antitumor vaccination using AAV serotypes 5 and 6 expressing a truncated neu oncogene in a neu-positive murine TUBO breast cancer model. Mice receiving a single oral administration of AAV5-neu or AAV6-neu demonstrated improved survival. Oral vaccination significantly improved survivals compared with intramuscular vaccination. Mice vaccinated with AAV6-neu survived longer than those treated with AAV5-neu. Vaccination with AAV5-neu or AAV6-neu induced both humoral and cellular immune responses against the NEU antigen. These responses were more robust in the mice undergoing oral vaccination compared with mice receiving the intramuscular vaccination. Protection from tumor was long lasting with 80% of the animals treated with oral AAV6-neu surviving a re-challenge with TUBO cells at 120 and 320 days post-vaccination. Further evaluation of AAV-based vectors as tumor vaccines is warranted.     

接种IL—6基因转导的白血病细胞后局部病理形态学实验研究

将人白细胞介素6(IL-6)基因转导的高分泌IL-6的FBL-3红白血病细胞克隆株体外扩增后,接种至C57BL/6小鼠皮下,观察肿瘤生长情况,并于不同时间取接种处组织作常规病理、免疫组化及电镜检查。结果表明接受IL-6基因转导的FBL-3细胞接种后的小鼠成瘤晚、生长速度慢,且肿瘤接种局部可见大量粒细胞和部分浆细胞、淋巴细胞的浸润,接种处组织免疫组化显示增殖细胞核抗原阳性率显著降低,提示IL-6基因转导的白血病细胞在体内致瘤性降低与其接种局部某些杀伤细胞浸润而诱导机体抗肿瘤免疫功能增强有关。     

Prevention of hepatic tumor metastases in rats with herpes viral vaccines and gamma-interferon.

Previous studies showed that gammaIFN decreases metastatic hepatic tumor growth by stimulating Kupffer cells (KC). The present studies examine whether lymphocyte stimulation via cells engineered to secrete GM-CSF or IL-2 decreases hepatic tumor growth, and whether stimulation of both macrophages and lymphocytes is more effective than either individually. Rats were immunized with irradiated hepatoma cells transduced by herpes viral amplicon vectors containing the genes for GM-CSF, IL-2 or LacZ. On day 18, half of each group was treated with 5 x 10(4) U gammaIFN, or saline intraperitoneally for 3 d. On day 21, all rats received 5 x 10(5) hepatoma cells intrasplenically. On day 41, rats were killed and tumor nodules were counted. Separate rats underwent splenocyte and KC harvest for assessment of lymphocyte- and macrophage-mediated tumor cell kill in vitro. GM-CSF or IL-2 vaccines or gammaIFN decreased tumor nodules significantly (GM-CSF 13+/-4, IL-2 14+/-6 vs. control 75+/-24, P < 0.001). Combination therapy was more effective, and completely eliminated tumor in 4 of 12 IFN-GM-CSF and 8 of 11 IFN-IL-2 animals. Additional rats underwent partial hepatectomy, an immunosuppressive procedure known to accelerate the growth of hepatic tumor, following tumor challenge. Therapy was equally effective in this immunosuppressive setting. Vaccination is associated with enhancement of splenocyte-mediated tumoricidal activity, whereas the effect of gammaIFN is mediated by KC. GM-CSF and IL-2 vaccine therapy and pretreatment with gammaIFN represent effective strategies in reducing hepatic tumor. Combination therapy targets both lymphocytes and macrophages, and is more effective in reducing tumor than either therapy alone.