Injection Of rIL-2 Research Articles

IL-2 and regulation of stress hormones and BDNF neurotropic factor levels after experimental traumatic brain injury (TBI)

Experimental traumatic brain injury (TBI) causes a stable stress response and changes the expression of various cytokine genes and neurotrophic factors. The goal of this study was to reveal changes in the levels of the corticosterone and testosterone hormones and the BDNF cytokine in blood serum, as well as the expression of the BDNF gene in hypothalamus in order to determine the opportunity of correcting the TBI damage with rIL-2. We used a rat model of “dropping load”: mild TBI was caused by falling of the 115 g load from the height of 80 cm, or 120 cm to produce a moderate-degree trauma. After TBI (immediately, or 72 hours later), the rats were injected daily with recombinant human interleukin-2 (Roncoleukin) at a dose of 30 μg/kg, a total of 3 injections. Control animals (also with TBI) received 0.15 M NaCl injections. Blood serum concentrations of corticosterone, testosterone, and BDNF were measured with ELISA tests. BDNF gene expression in hypothalamus was measured using RT-PCR. Results: the experiments showed a relationship between hormone concentrations and severity of head injury. In mild TBI, blood corticosterone levels reached a peak 2 hours after the injury, while in moderate TBI, the peak concentration of corticosterone was lower, being delayed in time (after 24 hours). Corticosterone and testosterone concentrations changed reciprocally in the both groups of injured animals. With injection of rIL-2 in both groups, corticosterone and testosterone levels were significantly increased. On day 7 after TBI, the BDNF level in blood serum was decreased, but it was raised in experimental group that received rIL-2. On day 7, the increase of BDNF gene expression in hypothalamus was more pronounced, when rIL-2 was administered at 72 hours after the head injury. The revealed positive association of BDNF levels and glucocorticoid hormones after mild TBI, like as possible coordination of these parameters with rIL-2 injection after experimental moderate TBI provides a reason to assume that the favorable impact of rIL-2 on the CNS recovery after TBI is, in part, mediated by the mutual modulating interaction of BDNF and glucocorticoid hormones.

CORRECTION OF STRESS-INDUCED HORMONAL CHANGES BY THE RIL-2 MEDICATION IN EXPERIMENTAL TRAUMATIC BRAIN INJURY

Traumatic brain injury (TBI) leads to steady stress reaction that may substantially influence on posttraumatic period. Stress changes concentration of sex hormones too, that play role of neurosteroids in CNS. The aim of the study was to detect changes in corticosterone and testosterone concentration in serum of experimental animals during recovery period after TBI. And also to find possibility of disturbance correction by cytokine preparation rIL-2 (ronkoleukin). After TBI both experimental and control group of animals get daily injections of recombinant human interleukin-2. TBI decreased the level of corticosterone on 30%, the injection of rIL-2 increased it. Testosterone slightly changed after TBI. But it’s level increased when after TBI the injections of rIL-2 were done. The obtained results can be considered as evidence of the stress reaction normalization in animals after TBI and under the conditions of their treatment with rIL-2.

IMPACT OF AGING ON THE DEVELOPMENT OF NEUROIMMUNE DEFICIENCIES AFTER EXPERIMENTAL MILD TRAUMATIC BRAIN INJURY (TBI)

Patient’s age affects the course of posttraumatic inflammation and recovery after TBI. The goal of the research was to identify the differences in neuroimmune deficiencies in young and old animals after experimental TBI. The research was carried out using male Wistar rats aged 3 and 18 months. Mild TBI was caused by weight drop TBI model. A group of animals was injected abdominally with 30 mkg/kg recombinant human interleukin-2 (Ronkoleukin, Biotech) daily for three days, starting 72 hours after TBI. The control group consisted of intact animals and rats who did not receive rIL-2 prior to TBI (n = 5 for both groups). The results obtained have shown that old animals after mild TBI had different testosterone and proliferative activity levels than the young ones; the injection of rIL-2 led to an increase in neurotrophic factors (testosterone and BDNF) without causing additional activation of lymphocytes.

IMPACT OF RONCOLEUKIN (RIL-2) ON THE LYMPHOCYTE-TRIGGERING ACTIVITY OF MACROPHAGES AFTER TRAUMATIC BRAIN INJURY IN VARIOUSLY AGED RATS

IL-1β is involved in both brain damage process and the mechanisms of brain regeneration processes. The goal of the present research is to measure the change in the production of lymphocyte-activating factor (LAF) after experimental traumatic injury (TBI) in variously aged rats and evaluate the possibility to correct LAF production with roncoleukin (rIL-2). LAF activity in the supernatants of peritoneal macrophages of injured rats was measured by its ability to have comitogenic effect on the proliferation of rat thymocytes stimulated by suboptimal lectin doses. LAF stimulation index was defined as ratio of stimulated to unstimulated levels of LTF. Results and discussion. The strongest suppression of microphages’ cytokine-producing function was found in older rats after TBI. rIL-2 injection significantly reversed the injuries caused by TBI even in older rats. These data confirm that exogenic IL-2 is able to activate the functional characteristics of innate immunity cells and that is has a normalizing effect on the immune cells of the older animals.

CORRECTION OF DISTURBED NEUROIMMUNE INTERACTIONS IN EXPERIMENTAL TRAUMATIC BRAIN INJURY BY MEANS OF RECOMBINANT INTERLEUKIN 2

Traumatic brain injury (TBI) commonly proceeds as a severe disease with high morbidity that can lead to neurological disorders in some of these patients. TBI is associated by multidirectional abnormalities of immune system, which affect quantity and functions of T-, B-, and NK-lymphocytes leading to infectious complications or autosensibilization. Restoration of the disturbances in neuroimmune interactions after TBI may be achieved by means of immunomodulators that have neuroprotective properties and may potentially initiate regenerative CNS activity. IL-2 is a cytokine that possesses neurooperative and neuroprotective properties. In immune system, IL-2 is produced by T-cells in response to antigen stimuli; in CNS, by brain cells. Lack of IL-2 production by both T-lymphocytes and brain cells increases a possibility of autoimmune and inflammatory pathologies. The objective of present study was to evaluate possible effects of human recombinant IL-2 (rIL-2, Roncoleukin®, Biothech Ltd., Russia) upon state and correction of immune and neuro-endocrine TBI consequences. The study was performed in adult Wistar rats. Mechanical TBI was produced by the dropping load model. 72 hours after inflicting the TBI, r-IL-2, at dose 30 mg/kg was injected once a day for three times. The animals from control group received 0.15M NaCl solution over the same period. The results have shown that, within first hours and days after TBI, corticosterone levels showed a sharp increase, whereas testosterone concentrations were decreased.In parallel, an increase in cytotoxic and proliferative activity of splenocytes was revealed, as well as increased number of splenocytes at their late apoptotic stage. Three daily injections of rIL-2 resulted into a significant increase in corticosterone and testosterone levels in injured animals on the day 7 after TBI. The animals treated with rIL-2 have exhibited more rapid normalization of cytotoxic and proliferative activity of splenocytes and return to normal ratio of proliferating splenocytes vs. apoptotic cells. Therefore, usage of rIL-2 may correct neuro-endocrine and immune interaction disturbances after TBI and decrease risk of chronic neurological disorders in TBI patients.

Favorable Impact of Post-ASCT Consolidative Immunotherapy with RITUXIMAB, rINF-a2b and rIL2 on Overall Survival and Progression-Free Survival in Advanced Stage or Relapsed/Refractory Follicular Lymphoma: Results of a Phase II Study

Abstract 3066 Introduction:Advanced stage III/IV or relapsed/refractory follicular lymphoma (FL) can hardly be cured with conventional chemotherapy and patients, even after autologous stem cell transplantation (ASCT), experience innumerable relapse events occurring at decreasing progression-free intervals. Important progress was made since the introduction of RITUXIMAB as part of frontline chemoimmunotherapy or as maintenance after frontline treatment with or without ASCT. But, whatever the policy applied, no plateau is observed regarding overall survival (OS) and progression-free survival (PFS). Disease relapse, even in patients with documented complete remission (CR), is thought to be induced both by resistant minimal residual tumor cells and the lack of immunocompetent mechanisms to contain or eliminate them. Thus, it has been postulated that post-ASCT consolidative immunotherapy might eradicate minimal residual disease, based on antibody-dependent cell-mediated cytotoxicity (ADCC) mechanism, and have a favorable impact on relapse rate and even OS. This view has led to a considerable interest in immunotherapy as a promising therapeutic line to restore and enhance the impaired anti-tumor immune surveillance in the context of post-ASCT low tumor burden. Purpose:We conducted a phase II study to compare OS and PFS between patients with advanced or relapsed/refractory FL receiving consolidative immunotherapy combining recombinant interleukine-2 (rIL-2), recombinant interferon- α-2b (rINF- α-2b) and RITUXIMAB after ASCT, with the aim of controlling minimal residual disease, and other counterparts with FL receiving no further treatment after ASCT. Patients and Methods:From August, 1995, to October, 2009, 139 patients with FL were autografted in complete remission ≥1 or partial remission. Of these patients, 66 were considered eligible for immunotherapy. On adequate post-ASCT hematologic reconstitution, they received 4 weekly IV injections of RITUXIMAB administered on an outpatient fashion. This was followed by a home-based program of subcutaneous injections of rIL2 (6 million UI × 3 / week in 1st cycle; 9 million × 3 / week in 2d) and rINF- α-2b (1.5 million UI × 3 / week in 1st cycle; 3 million × 3 / week in 2d) administered over two 7-week cycles. These two cycles were separated by a two-week free interval. The other 73 patients did not receive any additional treatment after ASCT and served as controls. Results:The two groups were comparable regarding demographic characteristics, disease profile and treatment course, except that the control group had significantly less transformed FL (p =0.0156) and a higher mean treatment line number (p =0.018). Median OS and PFS were not reached in either the study group or the control group. OS, initially not different between the 2 groups (p =0.21), was found significantly higher in the study group after a cut-off follow-up time point of 86.6 months (p =0.017). A significantly higher PFS was also noted in favor of the study group over the control group (p =0.0131). With a median follow-up of 60 months (10 to 136) in the study group and of 82 months (0.7 to 174) in the control group, survival rate was 90.9% and 71.2%, respectively (p= 0.0034) and the overall relapse rate was 19.7% (13 patients) and 41.1% (30 patients), respectively (p= 0.0064). Adverse events were generally mild, consisting essentially of fever and chills with the rIL-2 and rINF- α-2b subcutaneous injections (rapidly controlled with PARACETAMOL), fatigue, grade 2 abnormal liver function tests in one third of patients and grade 2 or 3 cytopenias (anemia or neutropenia) in 40% of patients. Conclusion:These results confirm that post-ASCT immunotherapy with rIL2, rINF- α-2b and RITUXIMAB has a statistically significant impact on OS and PFS. In view of its tolerability, it appears to be quite feasible and safe and might be seen as a promising line of treatment designed for eradicating post-ASCT minimal residual disease and worth being tested within the frame of a randomized trial for validation as an essential step in the treatment algorithm of FL. Disclosures:No relevant conflicts of interest to declare.

Post-ASCT Consolidative Immunotherapy with RITUXIMAB, rINF-a2b and rIL2 In Poor-Risk DLBCL: Results of a Phase II Study

AbstractAbstract 3558 Introduction:A minority of patients with diffuse large B cell lymphoma (DLBCL) can really be cured and the early or late relapse rate remains a subject of major concern. The occurrence of disease relapse, even in patients with documented complete remission (CR), is thought to be induced both by resistant minimal residual tumor cells and the lack of immunocompetent mechanisms to eradicate them. Thus, it has been postulated that post-autologous stem cell transplantation (ASCT) consolidative immunotherapy might eradicate minimal residual disease and, therefore, reduce relapse rate and even improve overall survival (OS). This view has led to a considerable interest in immunotherapy as a promising therapeutic line to restore and enhance the impaired anti-tumor immune surveillance in the setting of post-ASCT low tumor burden. Purpose:We conducted a phase II study to compare OS, relapse-free survival (RFS), death rate and overall relapse rate between patients with poor-risk DLBCL receiving consolidative immunotherapy combining recombinant interleukine-2 (rIL-2), recombinant interferon-α-2b (rINF-α-2b) and Rituximab after ASCT, with the aim of controlling minimal residual disease, and other patients with poor-risk DLBCL treated with ASCT alone. Patients and Methods:On 180 patients, 27 with DLBCL from Brest, autografted in complete remission (CR) ≥ 1 or partial remission (PR), were considered eligible for the study. They received, on adequate post-ASCT hematologic reconstitution, 4 weekly IV injections of Rituximab administered on an outpatient fashion. This was followed by a home-based program of subcutaneous injections of rIL2 (6 million UI × 3/week in 1st cycle; 9 million × 3/week in 2d) and rINF-α-2b (1.5 million UI × 3/week in 1st cycle; 3 million × 3/week in 2d) administered over two 7-week cycles. These two cycles were separated by a two-week free interval. One hundred and fifty three patients from Brest, Lille and Tours did not receive any additional treatment after ASCT and served as controls. Results:The two groups were comparable, except for age, which was older in the study group (p=0.018) and for pre-ASCT response pattern, which was better in the control group. There was no influence of recruitment center, sex, disease Ann Arbor stage, IPI score, RITUXIMAB administration before ASCT, graft source or ASCT conditioning regimen on the final results. Median OS and RFS were not reached in any group and are still under study. The median follow-up was 54.9 months in the study group and 48.8 months in the control group. In univariate analysis, the prevalence of death rate was 7.4% and 26.2% in the study group and the control group, respectively (OR = 0.23, 95%CI [0.05-0.99], p=0.03), and the overall relapse rate was 11.1% (3 patients) and 22.9% (35 patients), respectively (OR=0.42, 95%CI [0.12-1.48], p=0.17). In multivariate analysis, the risk of death was significantly decreased (OR 0.196; 95%CI [0.046-0.827] p=0.027) and there was a trend toward a decreased relapse rate (OR 0.348; 95%CI [0.104-1.168], p=0.088) in the study group compared to the control group. In addition, older age was independently associated with an increased risk of death (OR=1.053, 95%CI [1.02-1.09], p=0.002).Adverse events were generally mild, consisting essentially of fever and chills with the rIL-2 and rINF-α-2b subcutaneous injections responding well to PARACETAMOL, fatigue, grade 2 abnormal liver function tests in one third of patients, grade 3 neutropenia in 45% of patients and hypothyroidism in one patient. Conclusion:We found that post-ASCT immunotherapy with rIL2, rINF-α-2b and RITUXIMAB has a statistically significant favorable impact on death rate and a positive, although not statistically significant, effect relapse rate. In view of its toxicity profile, it appears to be quite feasible and safe and might be considered as a promising line of treatment designed for post-ASCT minimal residual disease and worth being evaluated within the frame of a prospective randomized trial. Disclosures:No relevant conflicts of interest to declare.

Interleukin-2 treatment effect on imatinib pharmacokinetic, P-gp and BCRP expression in mice

The aim of this study was to investigate the effect that recombinant interleukin-2 (rIL-2) (0.16 MUI/injection) had on the pharmacokinetics of imatinib (IM) in plasma. In this study, IM was given orally to mice at a dose of 150 mg/kg once a day for 11 days (from day 1 to 11) either alone or in combination with intraperitoneal injections of rIL-2 twice a day from day 8 to 11. Pharmacokinetic parameters were determined using WinNonLin software. Areas under the curve were compared using Bailer's method. The repeated administration of the rIL-2+IM combination was shown to have two pharmacokinetic advantages compared with repeated IM doses alone. In addition to the pharmacodynamic interest of this treatment, we found that the combined treatment significantly increased the IM Cmax (P<0.05) and significantly increased the IM trough concentration (C(24 h)) (P<0.01), which was always above the minimum therapeutic IM concentration (1 mumol/l) in plasma. Those pharmacokinetic modifications may be explained, in part, by a decrease in the P-glycoprotein expression in the three intestinal segments of the mice (duodenum, P<0.01; jejunum, P<0.05; and ileum, P<0.05) and a decrease in BCRP expression in the duodenum segment (P<0.05) due to rIL-2. In another experiment, we found a significant induction of intestinal P-glycoprotein expression in mice that had been given IM orally (150 mg/kg) twice a day for 11 days. It would be interesting to further investigate the IM disposition associated with rIL-2 treatment for clinical applications.

Engineering Human Tumor-specific Cytotoxic T Cells to Function in a Hypoxic Environment

Hypoxia occurs in many tumors and reduces the effectiveness of radio- and chemotherapy. Hypoxia also impedes immune responses to tumors, reducing T lymphocyte production of cytokines such as interleukin-2 (IL-2) and interferon gamma, as well as the survival and proliferation of these cells. We constructed a lentiviral vector encoding a bidirectional hypoxia-inducible responsive element (HRE) derived from human vascular endothelial growth factor, which drives the hIL-2 gene and a marker gene. We used a model of human B cell lymphoma to show that tumor-specific T cells modified with this vector upregulate hIL-2 expression when oxygen tension is low in vitro and in vivo. The consequence of this effect is to increase T-cell survival and proliferation whilst sustaining effector function, even in O(2) concentrations as low as 1%. The phenotype of the transduced cells is unchanged, as is their ability to migrate to tumor. HRE-IL-2-modified cytotoxic T lymphocytes (CTLs) produce faster and more complete tumor regression than parental CTLs and increase overall survival. Hypoxia-resistant T cells may thus be of value in the treatment of human tumors in which areas of hypoxia may otherwise account for resistance to this therapeutic strategy.

Treatment of eyelid lesion of angiosarcoma with facial artery recombinant interleukin-2 (rIL-2) injection

Treatment of eyelid lesion of angiosarcoma with facial artery recombinant interleukin-2 (rIL-2) injection

A novel approach for prevention of lethal GVHD by selective elimination of alloreactive donor lymphocytes prior to stem cell transplantation

Objective Experiments were designed to investigate a new concept aiming for induction of graft-vs-malignancy (GVM) effect prior to stem cell transplantation (SCT). Mismatched lymphocytes given pre-SCT will be followed by a selective elimination of alloreactive donor lymphocytes, thus avoiding lethal graft-vs-host disease (GVHD). Methods Recipient mice treated with sublethal total-body irradiation (TBI) received a single injection of allogeneic splenocytes, either naïve or rIL-2 activated (ADL), for induction of GVHD. To prevent lethal GVHD, cyclophosphamide (Cy) (200 mg/kg) or TBI (9 Gy) were given 4 days after cell inoculation. One day later, treated mice were rescued with syngeneic bone marrow cells. Results Both Cy and TBI significantly ( p < 0.001) prevented GVHD in all recipients inoculated with either naïve cells or ADL and all recipients survived more than 250 days. Control mice not rescued with CY or TBI died of GVHD within 20 to 25 days. A significant proportion of recipients inoculated with 4T1 tumor cells, treated with ADL followed by TBI 9 Gy, survived more than 250 days disease-free in comparison with 22 days in untreated control mice ( p <0.001). Conclusions Attempting to induce short, yet effective, GVM effects before rather than after SCT, thus avoiding lethal GVHD, may represent an innovative approach for more effective yet safer use of SCT for tumor immunotherapy.

ｒ‐ＩＬ２を含めた集学的治療を行ったＭＨＥの長期生存例

ｒ‐ＩＬ２を含めた集学的治療を行ったＭＨＥの長期生存例

Recurrent angiosarcoma effectively treated with superselective continuous intra-arterial injection of recombinant interleukin-2 combined with radiotherapy

We report a case of recurrent angiosarcoma (AS) in a 63-year-old man, effectively treated with a superselective continuous intra-arterial injection of recombinant interleukin-2 (rIL-2) combined with electron beam radiotherapy. The patient, who had undergone surgical resection for AS on his face near the nasal bridge, was admitted to our hospital because of recurrent AS on his bilateral cheeks. We placed 4-French catheters in the right external carotid artery (ECA) and superselectively in the left facial artery. A continuous intra-arterial injection of rIL-2 was administered in combination with radiotherapy using a 6 MeV electron beam. The lesion rapidly decreased in size. The total dose of rIL-2 was 3.72 × 107 IU (International Unit) in the right ECA and 2.96 × 107 IU in the left facial artery, while the total radiation dose was 50 Gy, in 25 fractions, for the tumor on the right cheek and 46 Gy, in 23 fractions, for the erythematous plaque on the left cheek. The patient was discharged with almost no cutaneous lesion on his cheeks. Unfortunately, there was another recurrence of AS and the patient died of respiratory failure due to lung metastases. However, as the lesion could be completely controlled even for a while, we believe this treatment method will contribute to the future management of AS.

Dose distribution of low-dose subcutaneous recombinant interleukin-2 affects the secondary release of interferon-gamma in vivo.

Human recombinant interleukin-2 (rIL-2) induced interferon-gamma (IFN-gamma) release in vivo was studied in 16 renal cell carcinoma patients treated with low-dose s.c. rIL-2. The s.c. administration of rIL-2 resulted in a significant increase in circulating IFN-gamma in all patients within 6 to 8 hours as measured by enzyme-linked immunosorbent assay (ELISA). Total IFN-gamma release, as expressed by the area under the concentration curve (AUC), and IFN-gamma serum peaks following repetitive s.c. rIL-2 injection showed a direct dose distribution dependancy, whereby significantly higher levels of secondary IFN-gamma were achieved in patients treated with 10 million IU rIL-2/m2 q 12 hours when compared with patients treated with 20 million IU rIL-2/m2 q 24 hours. IFN-gamma release was suppressed significantly in one patient who had been pretreated with corticosteroids, while prior immunotherapy with rIL-2 had no measurable effect on secondary IFN-gamma release in this study. Cumulative secondary IFN-gamma secretion, as expressed by the AUC, and IFN-gamma serum peak concentrations in response to s.c. rIL-2 did not correlate with response to therapy or survival of rIL-2 treated renal cell carcinoma patients.

Anti-tumor effects of local irradiation in combination with peritumoral administration of low doses of recombinant interleukin-2 (rIL-2).

The aim of this work was to improve radiotherapy results by immune stimulation. We tested the effects of a combination of radio- and immunotherapy, i.e., local low dose recombinant interleukin-2 (rIL-2) treatment, in two murine tumor models. Syngeneic tumors (SL2 lymphoma or M8013 mammary carcinoma) were induced subcutaneously on one or both flanks of mice. Irradiation was given either as a single dose (20 Gy) or fractionated (25 Gy) in 2 weeks. One or two cycles of rIL-2 were given concurrent with or subsequent to radiotherapy. One cycle of rIL-2 consisted of peritumoral injections administered on 5 consecutive days. Treatment effects were measured in terms of local tumor response and disease-free survival (DFS). The combined treatment modality was significantly better than treatment with either irradiation alone or rIL-2 alone. When tumors were inoculated on both flanks of the mice, combined radioimmunotherapy of one of the tumors also resulted in regression of the contralateral untreated tumor, indicating that a systemic anti-tumor immune reaction was induced. Additional rIL-2 injections did not enhance radiation toxicity. In conclusion supplementing irradiation with locally administered low doses of rIL-2 results in better local anti-tumor responses and DFS rates than either treatment alone without enhanced treatment toxicity. Furthermore, the local treatment induces a systemic anti-tumor reaction, influencing the growth patterns of a second, untreated tumor.

586 Concomitant interleukin-2-doxorubicin (ADR) schedule in patients (pts) with advanced soft tissue sarcomas (ASTS): A pharmacokinetic study

Adult patients (pts) with ASTS who relapse or fail to respond to a first line ADR-containing chemotherapy regimen are candidates for investigational treatment. Based on a concept of possible antitumor interactions and anticipated biochemical and pharmacological synergism between cytokines and cytotoxic drugs, we designed a phase II study in which ADR was concurrently administered with subcutaneous (SC) r-L2 in ADR-refractory or resistant ASTS. Pts received one injection of ADR alone (70mg/m²) and three weeks later a combination of r-IL2 (18MIU/m² dl to d5 SC) and ADR at the same dose either 1) 3 hours after the first r-IL2 injection (dl) or 2) at lymphocyte rebounds (d8). The same combination was repeated every 4 weeks according to the status of the disease. The main objective of this trial was to evaluate the impact of r-IL2 on ADR pharmacokinetic parameters. In this ongoing study, started in 6/94, 11 pts have been included, of whom, nine have received the two planned courses (c). As expected, in these 9 heavily ADR-pretreated pts, both local relapses and metastatic lesions remained unchanged (3 pts) or exhibited progression (6 pts) after ADR alone. Interestingly, 2 pts achieved a PR after 4 and 2 IL2/ADR c (1 PR in both arms), 2 a MR after 1 c (pts still on treatment), and 1 pt a dissociated response. The toxicity (T) of the combination was more substantial than with ADR alone: grade 3^_4leukoneutropenia (7 pts), grade 3^_4 thrombocytopenia (2 pts) and mucitis (5 pts). Total dose of ADR was reduced by 25% in all subsequent c. ADR infusion on dl IL2 c prevents lymphocyte rebounds in all pts. The evaluation of the impact of r-IL2 on ADR metabolism, the determination of immunological profiles in the two treatment arms and an analysis supporting a modulation of resistance to ADR by r-IL2 will be presented.

Reduction of EGP-2-positive pulmonary metastases by bispecific-antibody-redirected T cells in an immunocompetent rat model.

Effectiveness of bispecific-monoclonal-antibody (BsMAb)-mediated cellular anti-tumour activity was evaluated in vitro and in vivo in relation to the additional need for T-cell activation in a new immunocompetent rat tumour model. L37 tumour cells, derived from a squamous-cell carcinoma of the lung of Wag/Rij rats, were transfected with the cDNA coding for the human 38-kDa transmembrane pan-carcinoma-associated antigen EGP-2. Intravenous inoculation of EGP-2-positive L37 cells resulted in a rapid outgrowth of EGP-2-positive tumour nodules in the lungs. A BsMAb BIS-19, recognizing EGP-2 on the transfected tumour cells and the T-cell receptor of the rat, was made and allowed specific lysis of EGP-2-transfected L37 tumour cells by activated rat T lymphocytes in vitro. In vivo T-cell activation, assessed by up-regulation of IL-2-receptor expression, could be induced by daily injection of rat rIL-2. Intravenous treatment of tumour-bearing EGP-2-positive L37 tumour with BIS-19 together with rat rIL-2 resulted in almost complete disappearance of established tumour. In contrast, animals treated with BIS-19 alone, IL-2 alone or a combination of anti-EGP-2, anti-TcR and IL-2 showed much less or no tumour reduction. These results show effectiveness of systemic treatment with BsMAbs to induce anti-tumour activity in established tumours. Immune activation prior to or during treatment with BsMAbs, as achieved with IL-2, appears to be a prerequisite for successful treatment.

悪性血管内皮細胞腫 集学的治療を行った悪性血管内皮細胞腫の１例

A64-year-old man with Malignant hemangioendothelioma on the scalp and the face was successfully treated by combination therapy of rIL-2 injection, electron beam irradiation and surgical operation. One shot rIL-2 injection was conducted through the bilateral external carotid artery, followed by operation. On the operation, total scalp was excised and covered with free graft. As maintenance therapy, injection of rIL-2 has been performed 1-3 times a week.

Effect of lymphokine-activated killer cells with or without radiation therapy against malignant brain tumors.

The use of autologous lymphokine-activated killer (LAK) cells to treat malignant brain tumors was evaluated in 10 patients, one with metastatic malignant melanoma and nine with malignant glioma. LAK cells were obtained by culturing autologous peripheral blood lymphocytes with human recombinant interleukin-2 (rIL-2) for 7-28 days. All patients underwent surgery to remove as much tumor as possible and an Ommaya reservoir was implaced in the tumor cavity. Two of the 10 patients had received radiotherapy elsewhere, so were treated with LAK cells alone. Eight patients were treated with a combination of LAK cells and radiotherapy, using 1.8-2.0 Gy fractions given five times a week with a total dosage between 54 and 65 Gy. LAK cells and rIL-2 were injected to the tumor cavity via the Ommaya reservoir once a week for inpatients and once a month for outpatients. The duration of the LAK therapy ranged from 3 to 23 months (mean 13.7 mos). Neuroimaging evaluation revealed two complete responses, three partial responses, four no changes, and one progressive disease. In one patient with pontine glioma, the Karnofsky performance score was raised from 20 to 60. There were no side effects after the injection of LAK cells and rIL-2. The results suggest low-dose LAK therapy is a useful and safe treatment modality for malignant brain tumors.

Generation of tumor-specific cytotoxic T lymphocytes in vivo by combined treatment with inactivated tumor cells and recombinant interleukin-2.

In order to search for a new therapy that would maximize the effect of interleukin-2 (IL-2) in evoking antitumor immunity in vivo, the therapeutic effect of a combination of mitomycin-C(MMC)-treated tumor cells and recombinant IL-2 was examined for its induction of antitumor activity against established melanoma metastasis. In C57BL/6 mice intravenously (i.v.) injected with B16 melanoma cells on day 0, the combined treatment with an intraperitoneal (i.p.) injection of MMC-treated melanoma cells on day 6 and 2500 U rIL-2 (twice daily) on days 7 and 8 markedly reduced the number of pulmonary metastases. This antitumor activity was more effective than that in untreated controls and mice that were injected with MMC-treated melanoma cells alone or rIL-2 alone. When the i.p. injection of MMC-treated tumor cells was replaced by other syngeneic tumor cells, antitumor activity against metastatic melanoma was not induced. The antitumor activity induced by this treatment increased in parallel with an increase in the dose of rIL-2 injected. In contrast, an i.p. injection of soluble tumor-specific antigens alone could induce only a marginal level of antitumor activity, and this activity was not augmented by subsequent i.p. injections of rIL-2. In vivo treatment with anti-CD8 monoclonal antibody (mAb), but not with anti-CD4 mAb or anti-asialo-GM1 antibody, abrogated the antitumor activity induced by this combined therapy. This suggests that the antitumor effect was dependent on CD8+ T cells. Lung-infiltrating lymphocytes from mice that had been i.v. injected with melanoma cells 11 days before and were treated with this combined therapy, showed melanoma-specific cytolytic activity. This combined therapy also showed significant antitumor activity against subcutaneously inoculated melanoma cells. These results demonstrate that the combined therapy of an i.p. injection of MMC-treated tumor cells and subsequent and consecutive i.p. administration of rIL-2 increases antitumor activity against established metastatic melanoma by generating tumor-specific CD8+ CTL in vivo.