Augmentation of interleukin-2 immunotherapeutic effects by lymphokine-activated killer cells and allogeneic stimulation in murine tumor cells

Interleukin-2 (IL-2) and lymphokine-activated killer (LAK) cells were used in intraperitoneal and pulmonary tumor models in C57BL/6 mice. To maintain the immunotherapeutic effects of IL-2 plus LAK treatment but reduce its toxicity, ways were sought to augment IL-2 effects. The investigation showed that the adoptive transfer of LAK cells was a prerequisite for successful therapy of intraperitoneal cancer. When LAK cells were given on consecutive days within one course of immunotherapy, antitumor efficacy was augmented with additional doses of LAK cells. However, with the reduction of 1 complete cycle of IL-2 + LAK cells, no further reduction in intraperitoneal tumor was observed as compared to the reduction after 2 or 4 cycles. LAK cells generated from splenocytes of mice that had received an allogeneic tumor challenge 1 week earlier exerted a highly increased cytotoxicity as compared to normal LAK cells. Furthermore, the potentiation effect of an allogeneic response of the host at the tumor site was demonstrated by decreased numbers of lung implants and improved survival in mice given mixtures of syngeneic and allogeneic tumor cell suspensions. An alloimmune response within the microenvironment of tumor tissue markedly enhanced the antitumor effect of IL-2 against the syngeneic tumor. It was concluded that there is a fundamental need to improve the recruitment of adoptively transferred LAK cells or LAK precursors into tumor tissue. This may be the next step required in the further development of IL-2 and LAK immunotherapy.     

Local conditions in the host influence immunotherapy with interleukin-2 and LAK cells

Production of biological response modifiers through recombinant techniques has stimulated interest in immunotherapy of cancer. One of these, interleukin-2 (IL-2), will induce in vivo as well as in vitro proliferation of noncommitted T lymphocytes into lymphokine-activated killer (LAK) cells: cells cytolytic for a broad range of tumor cells. We have demonstrated earlier that immunotherapy with IL-2 and LAK cells will reduce tumor load and prolong survival in a significant way in an intraperitoneal (ip) tumor model as well as in other models. Nevertheless, mice die of one or two metastases escaping immunotherapy. Activation of the host immune system might boost endogenous IL-2 production. Activation might also enhance immunotherapy by increasing the necessary cofactors. Loco-regional allogeneic pretreatment ip 14 days prior to syngeneic tumor challenge did not enhance, but completely abrogated, ip IL-2 and LAK cell therapy (peritoneal cancer index, 0.6 +/- 0.3 vs 2.6 +/- 0.2, P2 = 0.003). Tumor bulk is not the reason for escape of immunotherapy either. One week after intracutaneous (ic) tumor inoculation a noncurative or sham tumor resection was performed, followed by IL-2 and LAK cell therapy either ip or in and around the tumor nodule. No significant difference in tumor diameter or survival of mice was seen. Allogenic tumor cells admixed with syngeneic tumor cells will induce an inflammatory reaction locally and regionally. This inflammatory reaction in the syngeneic host will enhance the treatment with IL-2. The allogeneic (P815) and syngeneic (MCA-105) tumor cell mixture was injected ic. Growth rate was retarded and survival prolonged in a significant way when the cell mixture was treated with ip IL-2 injections; no difference was seen when the admixture was not treated or the syngeneic ic tumor alone was treated with IL-2. We conclude that host immune status and recruitment of immunocompetent cells locally to the tumor site determine the outcome of immunotherapy with IL-2 and LAK cells.     

Generation of lymphokine-activated killer cells in strain 2 guinea pigs and their use in the therapy of L2C, an acute B-cell leukemia

Lymphokine-activated killer (LAK) cells were induced by incubating strain 2 guinea pig splenocytes or lymph node-derived cells in recombinant human interleukin-2 (IL-2) for 3-5 days. These effector cells had the morphology of lymphoblasts and were able to lyse murine P815 tumor cell targets. Fresh, unstimulated, guinea pig effectors were not capable of lysing these targets. The therapy of the L2C leukemia, an acute B-lymphoblastic leukemia of strain 2 guinea pigs, using LAK cells and recombinant IL-2 was examined. Antitumor effects were demonstrated by premixing LAK and tumor cells prior to intradermal injection in Winn type assays and then measuring the growth of local tumor and survival of the animals. In further experiments i.p. administration of LAK cells, 4 h following tumor cell inoculation by the i.p. route, prolonged the survival of treated animals. The best results in this i.p. therapy model were obtained with a 10-fold excess of LAK cells over tumor cells plus additional treatment with 1000 units of IL-2 for 20 days. This resulted in a 10-day increase in median survival of treated animals. Despite these in vivo antitumor effects, lytic activity of LAK effector populations against L2C targets could not be demonstrated in vitro. The potential synergy between LAK cells, IL-2, and a monoclonal antibody directed against the idiotype of the neoplastic cell surface immunoglobulin was also investigated. In these experiments enhanced survival of the combined treatment group, beyond that of either singly treated group, was not found. This study shows that LAK cells are useful agents in the therapy of a widely disseminated, aggressive, B-cell lymphoblastic leukemia. The use of such effectors, even in cases where in vitro lysis of the target tumor cell cannot be demonstrated, is encouraged by these results.     

Lysis of autologous melanoma cells by tumor-infiltrating lymphocytes: association with clinical response

Tumor-infiltrating lymphocytes (TILs) can be grown in vitro in medium containing interleukin-2 (IL-2). In clinical trials at the Surgery Branch of the National Cancer Institute, patients with metastatic malignant melanomas were treated with IL-2 plus the adoptive transfer of autologous TILs. At the time of treatment, TILs were assayed for in vitro lysis of fresh autologous and allogeneic melanoma cells and Daudi cells. Patients were evaluated for clinical response 4-8 weeks later. Lysis of autologous tumor cells by TILs was significantly higher for responding than for nonresponding patients. Tumor cells from responding and nonresponding patients were equally sensitive to lysis by allogeneic lymphokine-activated killer (LAK) cells. There was no difference between TILs from responding and nonresponding patients for lysis of LAK-sensitive Daudi cells, which was low in most cases and demonstrated that TIL lysis of autologous tumor cells was not due to LAK cells. The observed association of autologous tumor cell lysis by TILs with clinical response suggests that the development of culture methods to optimize lysis of autologous tumors may lead to increased response rates using this TIL treatment regimen.     

Alloimmune cells consume interleukin-2 and competitively inhibit the anti-tumour effects of interleukin-2

Adoptive immunotherapy with lymphokine activated killer (LAK) cells and recombinant interleukin-2 (IL-2) is successful in a variety of tumour models in both the normal and the immunocompromised mouse. We investigated the effects of an immune response to an allogeneic challenge on the metabolism of IL-2. Serum IL-2 levels at different time points after the administration of 20,000 units of IL-2 intraperitoneally were 2-4 fold higher in normal mice than in recently alloimmunized mice. In an intraperitoneal tumour model the alloimmunization of mice with allogeneic P815 tumour cells or splenocytes IP prior to the intraperitoneal inoculation of syngeneic tumour significantly diminished the anti-tumour effects of IL-2 and LAK cell immunotherapy in 7 consecutive experiments. High doses of IL-2 or pretreatment with cyclophosphamide restored the efficacy of IL-2 and LAK cell immunotherapy. From these results we hypothesize that T cells, activated by the allogeneic challenge, consume IL-2 and thus inhibit the effects of IL-2 and LAK cell treatment by competitive inhibition. LAK cell activity with reduced levels of IL-2 cannot be maintained and anti-tumour effects are lost. High doses of IL-2 were shown to overcome the competition for IL-2. Alternatively activated T-cells could be eliminated by pretreatment with cyclophosphamide and anti-tumour effects restored. These results are important in that they provide an alternative explanation as to the mechanism of non-specific cell mediated suppression and may in part explain the failure of some cancer patients to respond to treatment with IL-2 plus LAK immunotherapy.     

Intraperitoneal lymphokine-activated killer cell/interleukin-2 therapy in patients with intra-abdominal cancer: immunologic considerations

Lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) were administered by the ip route to patients with intra-abdominal malignancies. Pharmacokinetic studies of IL-2 revealed 10- to 100-fold higher concentrations of IL-2 in peritoneal fluid versus serum. Ip levels of IL-2 were maintained well above those required to generate and maintain LAK cells in vitro. LAK cell activity was detectable in the peritoneal fluid for the duration of each treatment cycle and did not disappear until IL-2 was discontinued. Detection of interferon-gamma (IFN-gamma) in the peritoneal fluid of all patients was consistent with production in situ by activated lymphocytes. In some patients, low but detectable levels of IFN-gamma were also found in the serum. In vivo activation of monocytes in the peritoneal fluid as measured by in vitro production of hydrogen peroxide was documented in the majority of patients. Neither interleukin-1 nor tumor necrosis factor-alpha was detected in the peritoneal fluid. We found no correlation between the presence or levels of IL-2, IFN-gamma, or LAK cell lytic activity in peritoneal fluid or serum and response or nonresponse to therapy.     

人天然白介素－2治疗恶性肿瘤的Ⅱ期临床观察

目的评价人天然白介素－２（ＩＬ－２）治疗恶性肿瘤的效果。方法采用ＩＬ－２加淋巴因子激活的杀伤细胞（ＬＡＫ细胞）全身输注治疗１４例实体瘤（恶性黑素瘤４例，肾癌２例，原发性肝癌和肠癌各３例，恶性淋巴瘤和恶性腮腺混合瘤各１例）和胸腹腔内注入治疗１０例癌性胸腹水（胃癌４例，卵巢癌２例，肠癌、乳腺癌、胰腺癌和肺癌各１例）。结果实体瘤缓解率为２１．４％（３／１４），胸腹水缓解率为７０％（７／１０）。不良反应有发热（＜３９℃）３例；恶心１例；肾功能障碍１例，停药后恢复正常。结论人天然ＩＬ－２具有一定的抗肿瘤作用。     

Inhibition by fibrin coagulation of lung cancer cell destruction by human interleukin-2-activated killer cells.

We examined the effect of fibrin coagulation on tumor cytotoxicity mediated by human lymphokine (IL-2)-activated killer (LAK) cells. LAK cells were induced from peripheral blood mononuclear cells (MNC) by culture with recombinant IL-2 for 4 or 5 days, and LAK cell-mediated cytotoxicity against tumor cells was assessed by 51Cr release assay in the presence or absence of plasma from normal subjects and lung cancer patients. Plasma did not affect the phase of induction of LAK activity by IL-2, but dose-dependently inhibited the effector phase of LAK cell-mediated cytotoxicity against Daudi cells. Similar inhibition of LAK cell-mediated cytotoxicity was observed on pretreatment of Daudi cells and human lung cancer cell lines with human fibrinogen plus thrombin. A parallel relationship was found between the amount of fibrinogen in plasma of lung cancer patients and inhibition of LAK cytotoxicity. This inhibition was reduced by addition of anticoagulants (heparin or argatroban). These findings suggest that fibrin coagulation on tumor cells protects them from LAK cell-mediated tumor cytotoxicity in malignant lesions and that a combination of an anticoagulant drug and IL-2/LAK therapy may be effective for treatment of lung cancer patients.     

Efficacy of chemoimmunotherapy with cyclophosphamide, interleukin-2 and lymphokine activated killer cells in an intraperitoneal murine tumour model

We have previously reported on the efficacy of intraperitoneal (i.p.) immunotherapy with interleukin-2 (IL-2) and adoptively transferred lymphokine activated killer (LAK) cells in an i.p. murine tumour model. Because of a dose-limiting toxicity associated with IL-2, cures are seldom observed. The development of treatment strategies that combine components that augment or synergise with the antitumour activity of IL-2 is crucial for the successful use of IL-2 in a clinical setting. Because of the known toxicity of high-dose IL-2 or high dose cyclophosphamide (CY) treatment, the goal of our experiments was to investigate the efficacy of chemoimmunotherapy with low or moderate doses of cyclophosphamide (CY) in combination with low or moderate doses of IL-2 with or without adoptively transferred LAK cells. Assessment of i.p. tumour growth 14 days after tumour inoculation, using the peritoneal cancer index (PCI) scoring system, demonstrated that combination treatment of established (day 3) i.p. tumour was clearly superior to single modality treatment. The effect was further enhanced by a second dose of CY at the end of a course of IL-2. Combination treatment led to a significant survival benefit. About 25% of the mice were cured, even when the dose of tumour cells at inoculation was increased. These experiments demonstrate the efficacy of combined treatment with IL-2, LAK cells and CY. Further research should be directed at the design of treatment schedules based on repetitive courses of chemoimmunotherapy associated with little toxicity.     

Interleukin 2 and lymphokine-activated killer cell therapy: analysis of a bolus interleukin 2 and a continuous infusion interleukin 2 regimen

Several groups have described the efficacy of interleukin 2 (IL-2) plus lymphokine-activated killer (LAK) cells in the treatment of cancer patients with significant response rates noted in patients with renal cell cancer and malignant melanoma; however, the optimum regimen remains undefined. The Biological Response Modifiers Program of the National Cancer Institute conducted two consecutive Phase I/II studies evaluating the toxicity and clinical efficacy of different methods of IL-2 and LAK cell therapy. In the first trial, we modified the standard Rosenberg regimen by decreasing the duration of priming in an attempt to reduce the toxicity related to this phase of the therapy and thereby administer more IL-2 doses with the LAK cells. In the second trial, we used a continuous i.v. infusion IL-2 regimen and altered both the leukapheresis procedure and the LAK cell culture techniques based on our in vitro and preclinical studies suggesting that 2-day LAK cells were superior. Thirty cancer patients received i.v. bolus IL-2 at 100,000 units/kg every 8 h for 3 days during priming and for 5 days during LAK cell administration. A second group of 22 cancer patients received IL-2 by continuous i.v. infusion at 3 x 10(6) units/m2 for 5 days during priming and an additional 5 days of IL-2 with the LAK cell phase of the treatment. The timing of the start of the leukapheresis procedures, their duration and number, and the LAK cell culture techniques differed in the two trials. Overall, 52 patients with various cancers were treated. The toxicities associated with each regimen were similar to those seen in other IL-2 plus LAK cell trials. Four patients (one each with melanoma and diffuse large cell lymphoma and two with renal cell cancer) exhibited partial responses lasting 2, 4, 10, and 15+ mo. Serial tumor biopsies from treated patients demonstrated that therapy can produce a marked mononuclear cell infiltrate and an increase in HLA-DR expression on tumor cells. There was no difference in the overall response rate between the two regimens, but toxicity was less with continuous i.v. infusion IL-2. The 5-day continuous i.v. infusion regimen resulted in significantly higher rebound lymphocytosis, cell yield from leukapheresis, and number of LAK cells harvested from culture.     

Inhibition by Fibrin Coagulation of Lung Cancer Cell Destruction by Human Interleukin-2-activated Killer Cells

We examined the effect of fibrin coagulation on tumor cytotoxicity mediated by human lymphokine (IL-2)-activated killer (LAK) cells. LAK cells were induced from peripheral blood mononuclear cells (MNC) by culture with recombinant IL-2 for 4 or 5 days, and LAK cell-mediated cytotoxicity against tumor cells was assessed by ⁵¹Cr release assay in the presence or absence of plasma from normal subjects and lung cancer patients. Plasma did not affect the phase of induction of LAK activity by IL-2, but dose-dependently inhibited the effector phase of LAK cell-mediated cytotoxicity against Daudi cells. Similar inhibition of LAK cell-mediated cytotoxicity was observed on pretreatment of Daudi cells and human lung cancer cell lines with human fibrinogen plus thrombin. A parallel relationship was found between the amount of fibrinogen in plasma of lung cancer patients and inhibition of LAK cytotoxicity. This inhibition was reduced by addition of anticoagulants (heparin or argatroban). These findings suggest that fibrin coagulation on tumor cells protects them from LAK cell-mediated tumor cytotoxicity in malignant lesions and that a combination of an anticoagulant drug and IL-2/LAK therapy may be effective for treatment of lung cancer patients.     

Primary metastatic osteosarcoma: results of a prospective study in children given chemotherapy and interleukin-2

To improve the poor prognosis for children with metastatic osteosarcoma (OS), interleukin-2 (IL-2) was added to the standard treatment due to its capacity to activate lymphocytes and differentiate lymphocyte subsets into lymphokine-activated killer (LAK) cells that are capable of recognizing and killing various tumor cells. This study concerns a cohort of unselected patients aged < 18 years with metastatic OS, who were treated with IL-2, high-dose methotrexate, doxorubicin, cisplatin, ifosfamide, LAK reinfusion, and surgery, between 1995 and 2010. Thirty-five patients aged 4–17 years were involved. Thirty-two of the 35 patients underwent surgery on their primary tumor, and 25 had surgery on lung metastases too. Twenty-seven patients received IL-2 plus LAK reinfusion. The median follow-up was 130 months (77–228), and the 3-year event-free and overall survival rates were 34.3 and 45.0%, respectively. Eleven patients remained alive, all of whom achieved a complete surgical removal of the primary tumor and lung metastases (1 patient did not receive lung resections due to complete lung metastases remission). Patients who had a complete surgical remission of the primary and metastatic sites and who responded well to chemotherapy had a better event-free survival. These results confirm the importance of complete surgical remission and point to a noteworthy (though still be ameliorate) survival rate in our series of patients, underling a potential role for immunotherapy with IL-2 and LAK/NK cell activation.     

Biotherapy of malignant peritoneal effusions in ovarian carcinoma

Malignant peritoneal effusions often arise in patients with ovarian carcinoma. They are a hazardous complication of cancer. Systematic intraperitoneal chemotherapy is not necessarily followed by long-term remission and may even induce untoward side effects. Intraperitoneal interleukin-2 (IL-2) and IL-2/lymphokine-activated killers (LAK) biotherapy showed high efficacy in treatment of ovarian carcinoma patients suffering from peritoneal effusions. The objective effect was 80.1% and 82.6%, respectively. Our results suggest that intraperitoneal biotherapy may be extended to dealing with malignant peritoneal effusions in ovarian carcinoma.     

白介素－2的Ⅱ期临床试验报告

共１５９例各种类型的恶性肿瘤病人进入了Ⅱ期临床试验。２５例病人接受了白介素－２（ＩＬ－２）单独全身治疗（静脉或皮下注射）；６０例病人接受了ＩＬ－２＋ＬＡＫ细胞全身性治疗；４１例癌性胸水病人接受了ＩＬ－２胸腔内灌注；６例癌性腹水病人接受了ＩＬ－２腹腔灌注；２７例病人接受了ＩＬ－２瘤内注射。单用ＩＬ－２全身治疗的病人没有病例获得临床缓解，２３晚期肾癌接受了ＩＬ－２＋ＬＡＫ细胞治疗，５例获得部分缓解，有效率２２％：癌件胸水和腹水的有效率分别为６８％和６７％：ＩＬ－２瘤内注射的有效率为３０％。Ｔ４／Ｔ８比值、ＮＫ细胞活性和ＬＡＫ细胞活性在全身性ＩＬ－２治疗后均有显著升高，并有统计学意义。病人接受本试验所用的ＩＬ－剂量后的毒副反应主要为发热、畏寒或寒战、疲乏，全组病人均无发生严重低血压、液体潴留等毛细血管渗漏现象。     

Interleukin-10 gene transfer to peritoneal mesothelial cells suppresses peritoneal dissemination of gastric cancer cells due to a persistently high concentration in the peritoneal cavity

Interleukin (IL)-10 has potent biological properties including an inhibitory action on the proliferation and metastasis of various cancer cells. However, it is difficult to maintain a high concentration of this cytokine as it has a short half life. In this study, we evaluated whether peritoneal mesothelial cells (PMCs) could be suitable for maintaining a high concentration of IL-10 using adenoviral gene transfer. We also evaluated the therapeutic effects of an intraperitoneal injection with adenoviral vector containing mouse IL-10 gene (Ad-mIL-10) using a mouse peritoneal dissemination model of MKN45 gastric cancer cells. We demonstrated that in vitro transfection efficiency of a recombinant adenovirus containing the bacterial beta-galactosidase gene (Ad-LacZ) was approximately 10-fold higher for primarily isolated PMCs than MKN45. The entire peritoneum was transfected until 3 weeks after an intraperitoneal Ad-LacZ injection. Ad-mIL-10 treatment increased intraperitoneal IL-10 levels until 3 weeks after treatment, and then significantly inhibited peritoneal cancer growth by inhibiting angiogenesis. This treatment also improved cachexia and prolonged mice survival. We thus concluded that IL-10 gene transfer in PMCs could be a new strategy for the prevention of peritoneal dissemination of gastric cancer due to the resulting persistently high IL-10 concentration in the peritoneal cavity.     

Monoclonal antibody therapy of murine lymphoma: enhanced efficacy by concurrent administration of interleukin 2 or lymphokine-activated killer cells

Lymphokine-activated killer (LAK) cells have recently been shown to be very efficient effector cells for antibody-dependent cellular cytotoxicity. Thus, we explored, in a murine lymphoma model, administration of LAK-inducing doses of interleukin 2 (IL-2) or adoptive transfer of LAK cells as a means of enhancing therapy with tumor-specific monoclonal antibody (mAb). AKR/Cum (Thy-1.2+) hosts were inoculated on day 1 s.c. with the SL-2 thymoma of AKR/J origin (Thy-1.1+) and developed palpable tumor on day 4. Tumor-specific anti-Thy-1.1 IgG2a mAb, 1A14, was given on days 4 and 8 with 50,000 units/day IL-2 i.p. divided in two doses on days 4-12. Therapy with IL-2 or mAb alone had minimal activity, prolonging control median survival of 22 days to 25 and 29 days, respectively, whereas therapy with IL-2 plus mAb significantly prolonged median survival to 40 days. However, combined therapy did not result in cures and long term survival. The efficacy of combined therapy did not result from alterations in the biodistribution of mAb by concurrent IL-2 infusions, as determined by studies with radiolabeled mAb. The combined effect of in vitro generated LAK (10(8) cells) adoptively transferred i.v. with 1A14 on days 4 and 8 following SL-2 inoculation was also evaluated. This regimen had no detectable toxicity, and treatment of mice with LAK and mAb resulted in 60% long term survival compared with 17% or 0% for mice treated with mAb or LAK alone. Thus, the therapeutic effects of tumor-specific mAb was enhanced by in vivo administration of IL-2 or by adoptively transferred LAK, which may represent means to provide the host with increased antibody-dependent cellular cytotoxicity effector cells. Adoptively transferred LAK has the additional benefit of augmenting mAb therapy of tumor without the toxicity associated with the induction of such cells in vivo with high dose IL-2.     

Local administration of autologous lymphokine-activated killer cells and recombinant interleukin 2 to patients with malignant brain tumors

Lymphokine-activated killer cells (LAK cells) were induced from lymphocytes from patients with malignant glioma by using interleukin 2 (IL-2), and their killing activity was examined. Their LAK activity against Daudi cells was 66.2 +/- 13.1% and 48.7 +/- 12.7% against self glioma cells, 54.4 +/- 10.1% against K562 cells, 43.1 +/- 7.9% against Raji cells, and 33.5 +/- 16.2% against allogeneic glioma cells. The phenotype of these LAK cells was Leu 1 (++), 2a (+/-), 3a (++), 7 (+), and 11 (++). The phenotype of precursor LAK cells, on the other hand, was Leu 1 (-), 2a (-), 3a (+), 7 (-), and 11 (++). Other activated killer cells, including LAK cells, phytohemagglutinin-activated killer cells, autoactivated killer cells, and their precursor LAK cells, were studied serologically in order to identify their phenotypic characteristics. From these data, the LAK cell populations were considered to be polyclonal. Using these LAK cells plus IL-2, local adoptive immunotherapy was undertaken in 23 patients with recurrent malignant glioma. We injected, that is, autologous LAK cells plus IL-2 directly into the cavities of the brain tumors; 1.2 to 324 x 10(8) LAK cells per ml and 0.8 to 5.4 x 10(3) units of IL-2 were directly injected into the brain tumor by using an Ommaya reservoir. Definite tumor regression, improvement of some clinical symptoms, and continuous remission over 6 mo or more were observed in six, nine, and three patients, respectively. There were no marked side effects, except for slight fever and chill, in eight and three patients, respectively. These results suggested the possibility of induction of a sufficient number of LAK cells from the lymphocytes of the patients with recurrent malignant glioma, indicating that local adoptive immunotherapy by direct injections of LAK cells and IL-2 into the brain tumor will prove to be an effective means of immunotherapy. Additional follow-up of the patients will be required before its therapeutic value can be established.     

An Unusual Case of Peritoneal Carcinomatosis

The peritoneal surface remains an important failure site for patients with gastrointestinal and gynecologic malignancies. In the past, oncologists regarded peritoneal carcinomatosis as an incurable component of an intra-abdominal malignancy. During the last two decades, novel therapeutic approaches have emerged for peritoneal carcinomatosis patients. We report the first case of peritoneal carcinomatosis emerging from an extra-adrenal, intra-abdominal paraganglioma. This 49-year-old male was treated with cytoreductive surgery and hyperthermic intraperitoneal perioperative chemotherapy. Paragangliomas are rare tumors of neural crest-derived chromaffin cells and can originate either from the sympathetic or from the parasympathetic ganglia. It has been estimated that as many as 10% of the paragangliomas arise outside the adrenal glands. This case represents an unreported presentation of paraganglioma. Two possible origins of this malignancy, and the applied therapy, are discussed. We report the feasibility of cytoreductive surgery plus hyperthermic intraperitoneal perioperative chemotherapy in the treatment of this malignancy.     

Lymphokine-activated killer cell plus recombinant interleukin-2 therapy of erythroleukemia in mice

The antileukemic effects of lymphokine-activated killer (LAK) cells plus recombinant interleukin-2 (rIL-2) therapy were assessed in mice with Friend virus (FV)-induced erythroleukemia. LAK cells were generated by incubating normal spleen cells for 72 hr in the presence of rIL-2 (1000 units/ml). At the time of injection, the LAK cells were cytotoxic in vitro against FV-infected fibroblasts and NK-sensitive and -resistant tumor targets but not normal controls. To determine in vivo activity, fully leukemic mice (spleen weight greater than 0.75 g) were injected with either PBS or LAK cells (10(8) cells/mouse IV at 14 and 17 days post virus) and rIL-2 (10,000 units/mouse IP every 8 hr on days 14 through 18 post virus). More than 70% of the progressively leukemic mice experienced permanent leukemia regressions (disease-free for greater than 100 days) following LAK cell plus rIL-2 therapy. Regressions were characterized by return of spleen and liver weights to normal and elimination of virus-infected erythroid (CFU-E) and macrophage (CFU-C) progenitor cells from spleen and marrow. Leukemic animals treated with either LAK cells alone or IL-2 alone experienced only transient leukemia regressions. These results demonstrate that LAK cell plus rIL-2 treatment can induce permanent regressions in progressively leukemic mice and provide a responsive and manipulable model system to elucidate the mechanisms involved in this form of immunotherapy.     

Enhanced antimetastatic activity of lymphokine-activated killer cells purified and expanded by their adherence to plastic

We have recently reported a simple and reproducible technique for the purification and rapid expansion of homogeneous populations of large granular lymphocytes expressing a natural killer cell phenotype and high levels of broad antitumor cytotoxic activity [lymphokine-activated killer (LAK) activity]. This technique exploits the observation that, in the presence of recombinant interleukin 2 (rIL-2), large granular lymphocytes/natural killer cells become adherent to plastic surfaces, actively proliferate, and acquire high levels of LAK activity. Because of their adherent properties these cells have been termed adherent LAK or A-LAK cells. The present studies investigate the antimetastatic effects of A-LAK cells in a syngeneic rat model of experimental pulmonary and hepatic metastases. For pulmonary metastases, F344 rats received i.v. injections with a natural killer-resistant mammary adenocarcinoma, MADB106, and, for hepatic metastases, animals received an intrasplenic injection of MADB106 tumor cells followed by surgical splenectomy. Three days later, the animals were treated with A-LAK cells alone, A-LAK cells plus rIL-2, or rIL-2 alone. These treatments were compared to immunotherapy using standard cultures of LAK cells (unfractionated spleen cells) and rIL-2. The results indicate that the administration of unfractionated LAK cells plus interleukin 2 (IL-2) was effective in reducing established lung or liver metastases in this rat model. However, the results also indicate that purified populations of A-LAK cells in combination with rIL-2 demonstrate dramatic and superior antimetastatic effects when compared to LAK cells cultured under standard conditions. The antimetastatic effects of standard LAK cells or A-LAK cells plus IL-2 translated into significant survival benefits compared to animals receiving no therapy or IL-2 therapy alone. Survival after therapy with A-LAK cells plus IL-2 was significantly prolonged compared to treatment with standard LAK cells. These data suggest that purified populations of LAK cells (derived from natural killer cells) may prove superior for adoptive immunotherapy in the clinical setting.