Interleukin-12 transduced dendritic cells induce regression of established murine neuroblastoma

BACKGROUND/PURPOSE: Interleukin 12 (IL-12) is a potent proinflammatory cytokine that enhances cytotoxic T lymphocytes (CTL) and natural killer (NK) cell activity. The goal of these experiments was to assess whether adenoviral-mediated IL-12 expression by dendritic cells (DC) could induce an antitumor immune response in a murine model of neuroblastoma. METHODS: Syngeneic A/J mice were inoculated subcutaneously with 1 x 10(6) cells from a murine neuroblastoma-derived cell line (TBJ). Murine DC were transduced in vitro with adCMV-mIL-12, and 1 x 10(6) cells were injected intratumorally. Tumor growth in these mice was compared with control animals injected with enhanced green-filled protein (EGFP) transduced DC or saline. The role of CTL was evaluated through cytotoxicity assays. Immunohistochemical analysis of tumor, spleen, and lymph node was performed to characterize the behavior and fate of various populations of immune effector cells in these tissues. RESULTS: The tumors of mice injected with adIL-12 transduced DC all underwent complete regression over a 3-week period. Splenocytes isolated from mice 7 days after intratumoral injection of adIL-12 DC showed increased cytolytic activity relative to control animals in vitro. Immunohistochemistry of tumor and lymph tissue showed increased amounts of DC and T lymphocyte infiltration and a slight decrease in apoptosis relative to the control groups. CONCLUSIONS: Increased IL-12 production by DC induced a significant antitumor response in a poorly immunogenic murine neuroblastoma model. These results show the vital role of DC in the immunobiology of the disease, and that protection of these cells from tumor induced apoptosis is a critical aspect for immunotherapies treating this aggressive tumor.     

Cellular mechanisms of interleukin-12-mediated neuroblastoma regression

Background/Purpose: Interleukin-12 (IL-12) is a proinflammatory cytokine with potent antitumor effects. Previous studies from the authors laboratory showed regression of established neuroblastoma in mice vaccinated with IL-12 transduced dendritic cells (DC). Although regression was associated with intense T cell infiltration, the precise role of T cells is unknown. The purpose of this work is to study the cellular mechanisms in IL-12[ndash ]mediated tumor regression. Methods: Three groups of mice (n = 12) received subcutaneous inoculation with 1 [times ] 10⁶ murine neuroblastoma cells (TBJ). Anti-CD4 (T helper), anti-CD8 (T cytotoxic), or antiasialo-GM1 (natural killer) antibodies were injected intravenously at 3-day intervals to deplete various immune effector cell populations. Mice in each depletion group and the control (nondepleted) group were injected intratumorally on day 7 with 1 [times ] 10⁶ DC IL-12[ndash ]transduced DC. Tumors were harvested for morphometry and immunohistochemistry at 21 days. Results: CD4 depletion had no effect on tumor growth in either control or IL-12[ndash ]vaccinated animals. In contrast, CD8-depleted animals treated with IL-12[ndash ]transduced DC underwent initial regression followed by progressive tumor growth (P [lt ] .01). These tumors were smaller in size at the same time-point. However, NK cell depletion (antiasialo GM1) completely abrogated the antitumor effects of IL-12[ndash ]transduced DC, leading to progressive tumor growth from the outset. There was no difference between the control and treated animals in this group. Conclusions: Contrary to our hypothesis that IL-12 DC primarily function to stimulate a T cell[ndash ]mediated response, these data suggest that NK cells are essential for the initial antitumor response of animals treated with IL-12[ndash ]transduced DC. CD8+ T cells appear to be necessary effector cells for complete rejection of tumor and possibly memory. NK cells are responsible for the early immune response. Furthermore, CD4+ (T helper) cells did not play any role in IL-12[ndash ]induced regression. These results imply that for DC to generate an effective antitumor response against neuroblastoma both acquired and innate effector cells are required. J Pediatr Surg 38:199-204.     

Polymorphonuclear neutrophils promote rFGF-2-induced angiogenesis in vivo

BACKGROUND: The role of neutrophils in angiogenesis remains largely unknown. Recent evidence has shown that polymorphonuclear neutrophils (PMNs) produce several proangiogenic cytokines, including VEGF, TNF-alpha, IL-1, IL-6, and IL-8. In addition, PMN-derived proteinases promote endothelial cell migration. We hypothesized that PMNs may facilitate angiogenesis and that reducing circulating PMNs might alter the host angiogenic response. MATERIALS AND METHODS: We utilized a corneal pocket assay to compare rFGF-2-induced vessel formation in the corneas of mice with normal levels of circulating neutrophils to those in a neutropenic state. Circulating PMNs were reduced using serial intraperitoneal injections of monoclonal antibody to Gr-1. Slow release rFGF2 pellets were implanted into the corneas of neutropenic mice and controls. Corneal neovascularization, measured as vessel length and area of vessel in-growth, was quantified using slit-lamp microscopy on day 7. RESULTS: The average number of circulating PMNs was significantly reduced in the experimental group compared to the control group on days 1-7 (P < 0.05). No statistical differences in circulating monocytes or lymphocytes were observed from days 0 to 6. Mice in the experimental group had a vascular area of 2.58 +/- 0.2 mm(2) compared to 3.55 +/- 0.3 mm(2) in the control group (P < 0.05). CONCLUSIONS: Corneal neovascularization in response to rFGF-2 is diminished by PMN depletion. PMNs play an important role in facilitating rFGF-2-induced angiogenesis.     

Tamoxifen potentiates in vivo antitumor activity of interleukin-2

Tamoxifen, an antiestrogen with efficacy in treatment of both estrogen receptor-positive and negative breast tumors, may be immunomodulatory. We tested tamoxifen's ability to augment the antitumor activity of interleukin-2 (IL-2), a lymphokine capable of expanding and activating lymphocytes, in the treatment of established pulmonary metastases of the weakly immunogenic murine fibrosarcoma MCA-106. Age-matched C57BL/6 female mice bearing pulmonary metastases induced by a tail vein injection of MCA-106 tumor suspension (5 x 10(5) cells/mouse) were treated from days 3 through 12 with intraperitoneal saline solution or IL-2 (50,000 units twice a day). Half of the mice in each group received plain and the remainder received tamoxifen-treated (2 units/ml) drinking water ad libitum for the duration of the experiment. All mice were killed on day 18 for enumeration of pulmonary metastases. Compared with saline-treated control mice, IL-2 and tamoxifen reduced metastases by 66% (p less than 0.0002) and 30% (p less than 0.005), respectively. IL-2 and tamoxifen combined reduced metastases 95% (p less than 0.0002), significantly better than did IL-2 (p less than 0.02) or tamoxifen (p less than 0.0003) alone. In vitro, tamoxifen inhibited proliferation of the weakly estrogen receptor-positive MCA-106 tumor by approximately 30%. Tamoxifen had no effect on the generation of 3-day IL-2-activated lymphocyte cytotoxicity against both natural killer-sensitive (YAC) and natural killer-resistant (MCA-106) target cells. Both YAC and MCA-106 tumor became more resistant to lysis with increased concentration of tamoxifen. This is the first demonstration of in vivo potentiation of IL-2 antitumor activity by tamoxifen and suggests its possible use clinically.     

IL-18对胰腺炎肠黏膜M细胞的影响

目的 探讨IL-18对胰腺炎肠黏膜M细胞功能的影响.方法 SD大鼠随机分为:IL-18治疗6 h组、12 h组、24h组,胰腺炎6 h组、12 h组、24 h组及对照组.检测血清IL-27、TNF-α、淀粉酶、谷丙转氨酶、总胆红素、内毒素等水平.检测肠系膜淋巴结移位细菌菌落数.病理切片,观察肠黏膜和胰腺组织学形态.采用二苇免疫荧光染色,观察小肠淋巴滤泡相关上皮内M细胞TNF-α、NF-кB、IL-27情况.激光捕获显微切割获取肠黏膜M细胞,检测小肠淋巴滤泡相关上皮内M细胞TNF-α、NF-кB mRNA的表达水平.结果 血TNF-α在AP组升高,在IL-18 6 h组、12 h组升高,但在IL-18 24 h组下降.IL-27在AP组均升高,在IL-18 6 h组上升,在IL-18 24 h组下降至阴性对照组水平.IL-18各组TNF-α表达增加.NF-кB在AP组和IL-18组的表达增加,以IL-18组更明显.IL-27蛋白在AP组和IL-18组的表达均增加.小肠淋巴滤泡相关上皮内M细胞TNF-α mRNA的表达在AP各组及IL-18组均高于对照组(P<0.05),IL-18 6 h组和IL-18 24 h组均高于AP组(P<0.05),并随时间逐渐升高.NF-кB mRNA的表达在IL-18组均高于AP组(P<0.05),且以术后12 h达高峰,24 h有所下降.结论 IL-18可能引起M细胞细胞因子的变化,对M细胞功能产生影响,进一步影响肠黏膜屏障的功能.     

Interleukin-1 and interleukin-2 defects associated with murine graft-versus-host-induced immunodeficiency

In this study we investigated the mechanism, or mechanisms, involved in graft-versus-host (GVH)-induced T cell immunodeficiency. Chronic GVH reactions were induced in normal CBA X A F1 (BAF1) hybrid mice by the injection of parental A strain lymphoid cells. At various times (43-91 days) after GVH induction, the functional status of GVH T cells was assessed using interleukin-1 (IL-1) and interleukin-2 (IL-2) as probes. The response of GVH thymocytes to IL-1 was depressed when compared with normal thymocytes. Although GVH peanut-agglutinin-negative (PNA-) thymocytes did respond to IL-2 alone or IL-2 plus phytohemagglutinin (PHA), this response was significantly lower than the response of PNA- thymocytes from normal mice. In addition, GVH spleen cells failed to produce significant amounts of IL-2 when stimulated with concanavalin A. These results suggest that the long term immunosuppression associated with murine chronic GVH disease is due, at least in part, to a decrease in the responsiveness to IL-1 and IL-2, and to a marked deficiency in IL-2 production.     

Enhanced in vivo therapy of pulmonary metastases with interferon and interleukin-2

Interleukin-2 (IL-2) can mediate in vivo tumor regression at high doses. To enhance this efficacy, we studied the effect of adding a human hybrid recombinant interferon alpha A/D (rHuIFN-alpha-A/D) because of its known in vitro augmentation of immune-mediated tumoricidal activity. C56BL/6 mice bearing established pulmonary metastases induced by the iv injection of the methylcholanthrene-induced fibrosarcoma MCA 106 were treated for 12 days with intraperitoneal injections of (1) Hanks' balanced salt solution, (2) recombinant IL-2, (3) rHuIFN-alpha-A/D, and (4) a combination of IL-2 and HuIFN-alpha-A/D. IL-2 and interferon each had some antitumor activity. However, maximal reduction of pulmonary metastases consistently resulted from combining IL-2 with interferon. In two of four experiments, this combination was significantly better compared to either IL-2 or interferon treatment alone. The most potent regimen was 12 days of IL-2 (50,000 units bid) together with rHuIFN-alpha-A/D (50,000 units ip qd). No consistent pattern of proliferative or cytotoxic activity was found against a panel of stimulator and target cells. These results demonstrate enhanced antitumor efficacy of combining recombinant interferon alpha and IL-2 against established pulmonary metastases. Potential clinical applications are suggested by these data.     

Vaccinia colon oncolysate immunotherapy for murine hepatic metastases can be modulated with low-dose interleukin-2. Third place winner: Conrad Jobst Award

A murine colon cancer hepatic metastases model was developed via intrasplenic injection of C-C36 tumor cells in syngeneic Balb/c mice to determine the potential efficacy of vaccinia colon oncolysate (VCO) immunoprophylaxis and therapy with and without low-dose interleukin-2 (IL-2) immunomodulation. Mice were injected with 40 micrograms VCO subcutaneously, either prophylactically or therapeutically. IL-2 (Hoffman-La Roche, Nutley, NJ) was administered at a dose of 25,000 units intraperitoneally twice daily for three consecutive days, prophylactically, therapeutically immediately after tumor challenge (early), or 9 days after tumor challenge (late). Mice were followed for 50 days after tumor challenge, and mortalities were recorded. Mice receiving VCO alone did not demonstrate better survival than controls. However, mice receiving VCO with IL-2 immunomodulation demonstrated consistently better survival than mice treated with IL-2 alone or controls. The group receiving VCO therapy with late IL-2 modulation (75% survival demonstrated improved survival over controls (0% survival, P less than 0.00001), VCO-treated mice (0% survival, P less than 0.005), and IL-2-treated mice (29% survival, P = 0.07). In vitro assays revealed enhanced NK activity and suggested cytotoxic T-lymphocyte (CTL) induction as possible mechanisms responsible for these biologic effects. Combined VCO and IL-2 immunotherapy may be of potential benefit to patients with metastatic colon cancer, but further research is required to optimize treatment regimens.     

人白细胞介素-15与18协同增强肿瘤浸润淋巴细胞体内对结肠癌细胞的杀伤功能

目的 观察白细胞介素(IL)-15与IL-18体内增强肿瘤浸润淋巴细胞(TIL)杀伤功能的效果.方法 用IL-15与IL-18共同刺激从结肠癌患者分离得到的TIL,通过测定其分泌转化生长因子(TGF)-β、IL-4、干扰素(IFN)-γ水平以及TIL的杀伤活性.用IL-15与IL-18共同刺激的TIL与结肠癌细胞SW480共孵育后,接种到SCID鼠皮下,测定肿瘤生长的大小、肝脏转移的肿瘤结节多少、血清中IL-4、IFN-γ水平以及腹腔巨噬细胞的吞噬能力.结果 IL-15与IL-18共同作用于TIL,能够抑制TGF-β、IL-4的分泌(P＜0.05),促进IFN-γ的分泌(P＜0.05).IL-15与IL-18共同作用于TIL后,能明显提高TIL对结肠癌细胞SW480的杀伤活性(P＜0.05).肝脏转移的肿瘤结节明显减少,血清中IFN-γ水平明显升高,腹腔巨噬细胞的吞噬能力增强.结论 IL-15与IL-18协同刺激体内能增强TIL对结肠癌细胞的杀伤功能.     

Recombinant interleukin-2-induced regression of pulmonary metastasis of renal cell carcinoma

A patient having renal cell carcinoma with multiple pulmonary metastasis was treated with recombinant interleukin-2. Pulmonary metastatic nodes were markedly diminished. The response was maintained for 4 months. At Autopsy, many fibrotic areas in which metastatic carcinoma was thought to have previously existed and then healed were observed in the bilateral pulmonary lobes, although a few microscopically tiny metastatic lesions still remained.     

The effect of chloroquine and hyperthermia on murine neuroblastoma

A number of reports suggest that hyperthermia is an effective adjunctive treatment modality in management of neural crest tumors. Recent studies have demonstrated a synergistic effect of induced hyperthermia when coupled with chloroquine in an in vitro model. This study examines the effect of chloroquine and hyperthermia in an in vivo murine neuroblastoma model. Forty-seven Ajax white mice (weighing 20 to 30 g) received a subaxillary tumor burden (C-1300 murine neuroblastoma) per trochar (1.25 x 10(6) cells). The tumor was then incubated for 9 days. Mice were then divided into four groups: group 1, controls (n = 15); group 2, hyperthermia (n = 12); group 3, chloroquine (n = 10); and group 4, chloroquine with hyperthermia (n = 10). Hyperthermia was induced with 40 to 69 mW/cm2 at 2,450 MHz microwave radiation for 4 minutes to achieve a temperature of 41.5 degrees C for 10 of 14 treatment days. Chloroquine was administered intraperitoneally at a dose of 40 mg/kg body weight for 10 of 14 treatment days. Mice were weighed and tumor size was determined daily. Animals were killed on day 21 and postmortem examination was performed, with tumors graded histologically. Animal weight, tumor weight, and tumor size were similar for all groups (P greater than .05). Mortality was 6% in group 1, 25% in group 2, 50% in group 3, and 40% in group 4 (P less than .05). Rate of tumor metastases was also statistically different from controls: group 1, 0%; group 2, 60%; group 3, 90%; and group 4, 90% (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Dendritic cells transfected with interleukin-12 and pulsed with tumor extract inhibit growth of murine prostatic carcinoma in vivo

BACKGROUND: The induction of anti-tumor immune response by injection of dendritic cells loaded with specific antigen or transduced with genes encoding tumor-specific antigens have been studied in animal models and have shown promising anti-tumor effects. The impact of different routes of administration of dendritic cells on their anti-tumor effects is uncertain. METHODS: We examined the effect of injection of cloned dendritic cells, which were stably transfected with IL-12 and exposed to an extract of murine RM-9 prostate carcinoma cell antigens on tumor growth in vivo. The cloned dendritic cells were injected intramuscularly, subcutaneously, or intraperitoneally into C57BL/6 mice. Seven days later, the mice were inoculated subcutaneously with 100,000 RM-9 cells. The sizes of the resulting tumors were measured every 3 days. RESULTS: Compared with the wild type dendritic cells, the IL-12-transfected dendritic cells delayed tumor engraftment by 7 days (P=0.04), and reduced tumor growth by up to 80% (P=0.02). Among the three routes of injection, intramuscular injection was most effective. In contrast to wild type dendritic cells, IL-12-transfected dendritic cells induced infiltration of mononuclear cells into the tumors, and induced apoptosis and necrosis of tumor cells. Injection of IL-12-transfected dendritic cells also significantly delays tumor growth in the preexisting RM-9 tumors. CONCLUSIONS: We conclude that antigen-exposed, IL-12-transfected dendritic cells have potential as an immunotherapy for prostate carcinoma. Routes of administration of dendritic cells are critical for maximal anti-tumor effect.     

The induction of specific antitumor immunity by in vivo treatment with interleukin-1 and sonicated tumor extract in a murine model

BALB/c mice were pretreated intraperitoneally with interleukin-1 (IL-1) and sonicated tumor extract (SE) from plasmacytoma MOPC104E, 10, 7, and 4 days prior to the intraperitoneal or subcutaneous inoculation of MOPC104E cells, following which significant suppression was observed. The mean survival time and tumor diameter on day 21 were 46.7 days and 0 mm, respectively, in contrast to the 20.9 days and 20.4 mm of control mice. Mice pretreated with IL-1 and SE from MOPC104E (MOPC-SE) were not suppressed following fibrosarcoma MethA inoculation, which indicates the tumor specificity of immunity in this model. This systemically operating antitumor immunity was also achieved by the intramuscular administration of IL-1, or when tumor challenge was performed on day 7 or 14. Moreover, MOPC104E-specific delayed-type hypersensitivity was detected in these mice. The results of this study suggest the possibilities of a new type of active specific immunotherapy, which could prove useful as postsurgical adjuvant therapy for cancer patients.     

Conditioning of neonatal pigs using low-dose chemotherapy and murine fetal tissue before murine hybridoma transplantation

Immunosuppression, myeloablation, and the use of immunologically immature tissue can overcome major histocompatibility complex barriers by inducing tolerance. With the goal of inducing tolerance to BALB/c-derived murine hybridoma cells producing the 4C6 monoclonal antibody (mAb), we transplanted BALB/c fetal tissue into neonatal pigs during a regimen of low-dose conditioning with busulfan and cyclophosphamide. After the tolerance induction phase, animals received intraperitoneal injections of 4C6 mAb hybridoma cells. Evidence of persistence of injected cells over time was sought by molecular analysis of peripheral blood for the presence of mouse genomic sequences and circulating 4C6 mAb. Persistence of donor polymerase chain reaction signal during the entire duration of the study, detectable mAb titer for 6 weeks, and a twofold increase of mAb concentration after a boost hybridoma infusion was observed in one animal receiving six consecutive administrations of the conditioning regimen. Our model has the distinctive advantage of allowing functional monitoring of engrafted cells for studying tolerance induction strategies. In addition, this model could be the basis for approaches aimed at producing mAbs in tolerized large animals.