Lymphokines and cytokines as cancer treatment. Immunotherapy realized

Immunomodulatory Effect of Microglia-Released Cytokines in Gliomas

Microglia, a type of differentiated tissue macrophage, are considered to be the most plastic cell population of the central nervous system (CNS). Microglia substantially contribute to the growth and invasion of tumor mass in brain tumors including glioblastoma (GB). In response to pathological conditions, resting microglia undergo a stereotypic activation process and become capable of phagocytosis, antigen presentation, and lymphocyte activation. Considering their immune effector function, it is not surprising to see microglia accumulation in almost every CNS disease process, including malignant brain tumors. Large numbers of glioma associated microglia and macrophages (GAMs) can accumulate within the tumor where they appear to have an important role in prognosis. GAMs constitute the largest portion of tumor infiltrating cells, contributing up to 30% of the entire glioma mass and upon interaction with neoplastic cells. GAMs acquire a unique phenotype of activation, including both M1 and M2 specific markers. It has been demonstrated that microglia possess a dual role: on one hand, microglia may represent a CNS anti-tumor response, which is inactivated by local secretion of immunosuppressive factors by glioma cells. On the other hand, taking into account that microglia are capable of secreting a variety of immunomodulatory cytokines, it is possible that they are attracted by gliomas to promote tumor growth. A better understanding of microglia-glioma interaction will be helpful in designing novel immune-based therapies against these fatal tumors. Concluding, as microglia significantly may contribute to glioma biology, favoring tumor growth and invasiveness, these cells represent a valuable alternative/additional target for the development of more effective treatments for gliomas.

Effects of Cytokines on Oxygen Radical Production by Peripheral Blood Monocytes and Alveolar Macrophages in Patients with Lung Cancer

The effects of cytokines (interleukin-2, tumor necrosis factor-alpha and interferon-gamma) on the ability of peripheral blood monocytes and alveolar macrophages to produce oxygen radicals were examined by the chemiluminescence assay in patients with lung cancer. Oxygen radical production by peripheral blood monocytes before stimulation with cytokines was lower in the lung cancer group than in healthy controls, suggesting reduced immune function in lung cancer patients. However, the activity in the lung cancer group was elevated to the control level when the monocytes were stimulated by any of the three aforementioned cytokines. Oxygen radical production by alveolar macrophages did not differ significantly between nonstimulated monocytes from lung cancer patients and those from healthy controls. In the lung cancer group, stimulation of the macrophages with any of the three cytokines elevated their ability to produce oxygen radicals to the same extent as in the control group. The results suggest that stimulation of macrophages by interleukin-2, tumor necrosis factor-alpha or interferon-gamma can exert an antitumor action in patients with lung cancer.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Immunogene therapy as a treatment for malignant brain tumors in young mice

OBJECT

New and innovative forms of effective treatments for malignant brain tumors in children are urgently needed. The authors have previously shown that intracerebral injection into the tumor bed of allogeneic fibroblasts genetically engineered to secrete interleukin-2 (IL-2) results in prolongation of survival and an antitumor immunocytotoxic response in adult mice that harbor intracerebral gliomas. The first goal of this study was to determine if malignant gliomas (GI261) could be treated in mice (C57BL/6) in the pediatric age group (weanlings [2-3 weeks old] and adolescents [3-4 weeks old]). The second goal was to determine the effectiveness of using IL-2-secreting allogeneic fibroblasts as a protective vaccine to prevent the development of intracerebral gliomas in these young mice.

METHODS

Using GI261 glioma cells derived from a spontaneously arising glioma in C57BL/6 immunocompetent mice, animals 2 to 4 weeks of age received an intracranial injection of 5 x 10(4) tumor cells into the right frontal lobe through a bur hole. The treatment vaccine consisted of 10(6) allogeneic IL-2-secreting fibroblasts, given at the time of tumor injection (treatment experiments) or at three weekly intervals prior to tumor injection (protection experiments). Control groups received either medium or nonsecreting allogeneic fibroblasts. The effects of this treatment on survival and long-term immunity were investigated. The results demonstrate a significant prolongation of survival in animals harboring intracerebral gliomas that were treated with intracerebral injections of IL-2-secreting allogeneic fibroblasts (p < 0.05). Morbidity and mortality rates did not increase as a result of intracerebral immunization. Compared with naive controls, long-term survivors demonstrated immune memory, as evidenced by prolongation of survival when they were rechallenged with tumor cells. The results of the protection experiment demonstrate a significant delay (p < 0.005) in the development of gliomas in the animals pretreated with either allogeneic nonsecreting or allogeneic IL-2-secreting fibroblasts prior to the introduction of tumor cells. In addition, in 78% of these animals a tumor did not develop when rechallenged.

CONCLUSIONS

These results demonstrate the efficacy and safety of using intratumoral injection of IL-2-secreting allogeneic fibroblasts as a treatment or protective vaccine in young mice. It is hoped that these preclinical studies will lead to a clinical trial for the treatment of malignant brain tumors in children.

Optimization of protein therapies by polymer-conjugation as an effective DDS

Due to recent advances in disease proteomics, many disease-related proteins have been found. It is expected that there will be therapeutically useful proteins among them. However, it is clinically difficult to use most proteins as effective and safe drugs because of their very low stability and pleiotropic actions in vivo. To promote disease proteomic based drug development for protein therapies, we have attempted to develop an optimal polymer-conjugation system for improving the therapeutic potency of proteins. In this review, we introduce this innovative protein-drug system.

Development of Novel Drug Delivery System (DDS) Technologies for Proteomic-Based Drug Development

With the success of human genome projects, the focus of life science research has shifted to the functional and structural analyses of proteins, such as disease proteomics. These structural and functional analyses of expressed proteins in the cells and/or tissues are expected to contribute to the identification of therapeutically applicable proteins for various diseases. Thus, pharmaco-proteomic based drug development for protein therapies is most noticed currently. However, there is a clinical difficulty to use almost bioactive proteins, because of their very low stability and pleiotropic actions in vivo. To promote pharmaco-proteomic based drug development for protein therapies to various diseases, we have attempted to establish a system for creating functional mutant proteins (muteins) with desired properties, and to develop a site-specific polymer-conjugation system for further improving the therapeutic potency of proteins. In this review, we are introducing our original protein-drug innovation systems mentioned above.

Treatment with allogeneic interleukin-2 secreting fibroblasts protects against the development of malignant brain tumors

We have reported that mice with an intracerebral (i.c.) malignant glioma or breast cancer treated with i.c. injection of allogeneic fibroblasts genetically engineered to secrete interleukin-2 (IL-2) survived longer than mice in various control groups. The goal of the present study was to determine the effectiveness of utilizing IL-2 secreting allogeneic fibroblasts as a protective treatment to prevent the development of an i.c. glioma or breast carcinoma. Using an intracranial microcannula system that we developed, the animals received weekly injections of the cellular vaccine prior to the introduction of tumor cells via the cannula. The results demonstrate a significant delay (P < 0.005) in the development of glioma in the animals pre-treated with either allogeneic non-secreting or IL-2-secreting fibroblasts prior to introduction of tumor cells. In addition, 50% of the animals pre-treated with IL-2 secreting allogeneic fibroblasts injected subsequently with G1261 glioma cells did not develop a tumor, while all of the animals injected with glioma cells alone and 92% of those treated with non-secreting fibroblasts eventually died. The long-term survivors from the pre-treatment group were subsequently re-challenged with tumor and compared to naive controls. There was evidence that long-term immunity was established in the pre-treated animals, since there was a significant prolongation of survival (P < 0.01). In similar experiments using breast cancer cells, 62% of the animals pre-treated with non-secreting allogeneic fibroblasts and 75% of the animals pre-treated with allogeneic IL-2 secreting fibroblasts subsequently injected with SB-5b breast carcinoma cells did not develop tumors and had a significant prolongation of survival. These data suggest that i.c. injection of allogeneic IL-2 secreting fibroblasts are effective as a protective treatment in the prevention of the development of a brain tumor when the fibroblasts are introduced into the same site where the tumor is subsequently injected.

Expression of biologically active recombinant equine interferon-gamma by two different baculovirus gene expression systems using insect cells and silkworm larvae

The full-length equine interferon-gamma (eIFN-gamma) cDNA, including the secretion signal peptide coding region, was recloned into baculovirus transfer vector pAcYM1. This vector was co-transfected with Autographa californica nuclear polyhedrosis virus DNA or hybrid nuclear polyhedrosis virus DNA into Spodoptera frugiperda cells. The recombinant viruses, named AcEIFN-gamma and HyEIFN-gamma, were then recovered. Recombinant eIFN-gamma (reIFN-gamma) was accumulated in the culture fluid of the AcEIFN-gamma or HyEIFN-gamma infected Tricoplusia ni -derived cell line, BTI TN 5B1-4, and hemolymph of HyEIFN-gamma infected silkworm larvae. These reIFN-gamma forms were shown to be 14, 16, 18 and 20kDa proteins, and glycosylated as confirmed by SDS-PAGE and tunicamycin treatment. Both reIFN-gamma proteins, showed high-level biological activities to vesicular stomatitis virus by cytopathic effect reduction assay, and MHC class II antigen induction on the equine fetal kidney-78 cell line.

Application of interleukin-2-secreting syngeneic/allogeneic fibroblasts in the treatment of primary and metastatic brain tumors

We found previously that mice injected intracerebrally (i.c.) with a mixture of malignant cells and allogeneic fibroblasts genetically engineered to secrete interleukin-2 (IL-2) survived longer than mice in various control groups. The primary goal of this study was to determine if an established i.c. glioma (Gl261) or breast carcinoma (SB-5b) could be treated by injection of IL-2-secreting allogeneic fibroblasts into the tumor region. As an additional objective, these results were compared with the effectiveness of injecting IL-2-secreting allogeneic fibroblasts prior to the introduction of the tumor cells as a means of preventing the development of an i.c. glioma or breast carcinoma. The results demonstrated that treatment of mice bearing an established i.c. glioma or breast carcinoma with IL-2-secreting allogeneic fibroblasts resulted in a prolonged survival. Furthermore, the results demonstrate a significant delay (P<.005) in the development of glioma in the animals treated with either allogeneic nonsecreting or IL-2-secreting fibroblasts prior to introduction of tumor cells. In addition, 50% of the animals pretreated with IL-2-secreting allogeneic fibroblasts injected subsequently with Gl261 glioma cells did not develop a tumor, whereas all of the animals injected with glioma cells alone and 92% of those treated with nonsecreting fibroblasts eventually died. Evidence also exists that long-term immunity was established in the treated animals because there was a significant prolongation of survival in comparison to naïve controls (P<.01) for those animals without evidence of glioma that previously had been immunized with treatment cells when challenged again with tumor cells. In a parallel experiment, 62% of the animals pretreated with nonsecreting allogeneic fibroblasts and 75% of the animals pretreated with allogeneic IL-2-secreting fibroblasts subsequently injected with SB-5b breast carcinoma cells did not develop tumors. The results indicate that IL-2-secreting allogeneic fibroblasts can be effective in the treatment of an established brain tumor. These data also suggest that i.c. injection of allogeneic IL-2-secreting fibroblasts is effective in prevention of the development of a brain tumor when the fibroblasts are introduced into the same site where the tumor is subsequently injected.

Cytokine immunogene therapy

The prognosis for patients with either a primary or metastatic brain tumor is poor. Clearly new forms of therapy to improve the long-term survival of patients with malignant brain tumors are urgently needed. The authors are in the process of developing a new and novel form of treatment for primary and metastatic brain tumors in which they use genes involved in growth repression. In particular most tumors fail to induce an antitumor immune response strong enough to kill the tumor. Under appropriate circumstances, however, immunity can be produced in unique structures on the tumor cells known as antigens. To prepare the vaccine, genes are transferred into a fibroblast cell line that causes the cell to produce cytokines, the potent proteins known to stimulate the immune system. These cells are subsequently injected into the tumor bed, resulting in the development of an antitumor immune response. In experiments described in this manuscript, the authors have investigated a number of ways of augmenting the immune response by administering this type of cellular vaccine. They found that mice with a primary intracerebral glioma, melanoma, or breast cancer treated with this allogeneic cytokine-secreting vaccine survived significantly longer than untreated mice. Additionally the vaccine was found to stimulate a systemic antitumor immune response, as shown by immunocytotoxic studies, histopathological examination, and delayed immune memory responses. In summary, these results indicate that immunogene therapy is a promising new targeted therapy for the treatment of intracerebral malignant tumors.

Effectiveness of a simply designed tumor vaccine in prevention of malignant melanoma development

We investigated the efficacy of a simple syngeneic tumor vaccine to induce specific antitumor immunity in female C57Bl/6 mice. Tumor vaccine was prepared by mixing irradiated B-16 melanoma tumor cells with the pleiotropic biological response modifier-maleic anhydride divinyl ether (MVE-2). Experimental animals were pretreated with the vaccine in order to prevent the development of intraperitoneal (i.p.) B-16 melanoma tumors after inoculation of viable tumor cells. More than 40% of prevaccinated animals challenged i.p. with 5 x 10(5) viable tumor cells were completely protected from tumor development and remained tumor-free 100 days after tumor cell inoculation. The percentage of tumor-free animals (survivors) rose to as much as 90% when the application of tumor vaccine was repeated two weeks after the first vaccination (i.e. one week after the inoculation of viable tumor cells). The induced antitumor response depended predominantly upon macrophage function, since vaccinated animals which were depleted of peritoneal macrophages died within the same time range as animals in the control group. Also, tumor-type specificity of the vaccine was confirmed by the fact that the animals vaccinated with B-16 melanoma vaccine were not protected from the development of another type of tumor. In conclusion, comparison of the experimental data with the data from the literature suggests that our simple tumor vaccine may be as effective as genetically engineered tumor vaccines. At the same time, this kind of vaccine is easier to control and thus safer to apply in humans when compared to genetically engineered vaccines.

Influence of peri-operative immunotherapy on serum cytokines and soluble cytokine receptors in patients undergoing surgery for colorectal cancer

OBJECTIVE

The cellular immune response is suppressed following surgery for colorectal cancer. As cytokines influence the patient's immunological responsiveness, we have measured serum cytokines and their soluble receptors in patients receiving peri-operative immunotherapy for colorectal cancer.

PATIENTS AND METHODS

Fifty-two patients were randomized to receive low dose recombinant IL-2 (rIL-2) alone; rIL-2 with interferon-alpha (IFN-α) or no immunotherapy. Serum cytokines and cytokine receptor levels were measured preoperatively and on post-operative days 1, 4, 7 and 10 using ELISA kits.

RESULTS

Circulating levels of IFN-γ were undetectable in the majority of patients, although IFN-γR levels were increased in all three groups on the first post-operative day (P < 0.05). Similarly, IL-2 was undetectable in most subjects and not enhanced by treatment. However, IL-2R was significantly induced in all patients (P < 0.001), and these levels were higher in both treatment groups when compared with control (P < 0.005). Tumour necrosis factor-alpha (TNF-α) was universally undetectable, but the TNF-R p55 and p75 subunits were induced in all patients (P < 0.005); and as with IL-2R, this was greater in the treatment groups (P < 0.01). Finally, IL-6 production was induced in all groups (P < 0.005), but this was only noted on day 1.

CONCLUSION

Soluble cytokine receptors are induced by surgery, and levels of IL-2R and TNF-R are enhanced by exogenous rIL-2 and rIL-2 with IFN-α. This augmentation suggests increased immunocompetence associated with low dose peri-operative immunotherapy.

Induction of tumor immunity by autologous B lymphoma cells expressing a genetically engineered idiotype

A fusion protein containing a B cell lymphoma idiotype (Id) and granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent stimulator of tumor immunity. In three different tumor models we show that immunization with autologous lymphoma cells that have been engineered to express the Id in the context of GM-CSF is much more effective than immunization with an equivalent dose of the purified protein. The lymphoma Id could be modified by introducing the GM-CSF gene into the immunoglobulin (Ig) heavy chain locus via gene targeting. This approach circumvents the isolation of the rearranged immunoglobulin variable genes from the tumor and the preparation of tumor-specific vector constructs. The low production of Id/GM-CSF fusion proteins by transfected cells, which is a major obstacle in the use of purified fusion proteins for immunotherapy, is due to the presence of the cytokine gene in the immunoglobulin locus. Low production, however, is not limiting in the cell-based setting, because upon in vivo administration of the modified autologous cells, even minute expression levels are sufficient to induce tumor immunity.

Expression of feline recombinant interferon-gamma in baculovirus and demonstration of biological activity

We have previously reported the cloning of the coding sequence for feline-specific interferon-gamma. Here, we describe the expression of this sequence in a baculovirus system and demonstrate the biological activity of the recombinant protein. The coding sequence for feline interferon was directionally cloned into the baculovirus transfer vector pAcCL29-1. Transfer vector and linearized wild-type AcMNPV (BacPAK6) were used to co-transfect Sf9 cells by calcium phosphate coprecipitation. Subsequently, wild-type and recombinant viruses were separated by plaque assay. Recombinant plaques were expanded and a master stock of virus is produced. Production of biologically active interferon-gamma from infected Sf9 cells was demonstrated using a standard cytopathic effect reduction assay, utilising vesicular stomatitis virus (VSV), and an MHC class II induction assay.

Gene therapy for colon cancer

The enormous number of newly diagnosed cases of colorectal cancer that occur each year and the lack of agents that are highly effective for all patients underscore the need for novel approaches to combating the disease. Gene therapy as a developing treatment modality is already well established, with a number of trials ongoing and a vast range of other approaches being assessed in animal and cell culture experiments. In this brief review, we have discussed five gene therapy trials in colon carcinoma that are ongoing or in the approval process in the United States. The gene therapy approaches being employed can be divided into three major categories: (1) enzyme/prodrug systems (HSVtk/ganciclovir; CD/5-fluorocytosine); (2) tumor suppressor gene replacement therapy with wild-type p53; and (3) immune-gene therapy which is based on cytokine or tumor antigen expression to induce tumor immunity (e.g., CEA). Replication-deficient recombinant adenoviral vectors are predominantly used for colon cancer gene therapy, because they can be produced at high titer and they readily infect a number of different cell types. One trial uses polynucleotide therapy for antitumor immunization with intramuscular injection. All of these studies are phase I trials, principally designed to evaluate safety, but they will also provide data on gene delivery. Some trials may provide some insight into potential therapeutic effects. We have alluded to some of the concerns on toxicity related to the use of adenovirus, risks and side effects from transgenes, lack of tumor-specificity of transgene expression, and potential problems with efficient gene delivery to solid tumors. The clinical trials, however, will provide insight that will inform design of future studies with respect to dose, form, and frequency of administration, as well as to the value of biologic and clinical endpoints. The molecular analysis of the fundamental basis of colon cancer has moved at a remarkable pace and that progress seems set to continue. Thus, the basic foundations for gene therapy are undoubtedly in place: a clinical need; growing understanding of basic tumor biology; and ever-improving delivery systems. The field is at a very early stage in its evolution, and one concern is that the considerable hurdles that must be overcome are seen as examples of the failure of cancer gene therapy; however, we believe these challenges will be overcome. The authors also believe that colon cancer gene therapy is likely to take new directions, such as use as adjuvant to radical surgery, rather than attempts to treat end-stage disease when the liver is replaced by metastases. Other new directions might include prophylactic gene-based immunization against a panel of well-characterized tumor antigens, at least for persons shown to be at high risk of colon cancer because of genetic or other predisposition. A marriage between gene therapy approaches and conventional anticancer treatments such as radiotherapy and chemotherapy also seems likely. There is already evidence of this move with demonstration of synergism between p53 replacement and radiotherapy and chemotherapy. It is also likely that therapies will be developed that combine elements from the cancer gene therapies discussed previously, namely, suicide gene transfer, immune modulation, and modulation of defective cancer genes. Perhaps one of the main concerns is not that researchers in cancer gene therapy want to walk before they can run, but that the public and government agencies believe they can. The next 10 years will be an interesting time in the development of novel treatments against colon cancer.

Immunological relatedness of the protective mechanisms against tuberculosis and cancer

BACKGROUND

Bacille Calmette-Guérin (BCG), an attenuated strain of tuberculous bacillus, is the source of vaccines providing unclear and variable protection against tuberculosis (TB) and cancer. Thermostable macromolecular antigens (TMAs) are major mycobacterial complexes immunodominant in disease. A60 (TMA complex of BCG) protects mice against TB development, via T lymphocyte (TL)-mediated macrophage (Mphi) activation, halting intracellular mycobacterial replication. In most A60-primed mice, cytolytic TLs and Mphi infiltrate cancer tissue, resulting in 80-100% rejection. Adoptive TL transfer is indispensable for Mphi-dependent tumour cell inactivation via oxygen and nitrogen radicals. Neoplasm development induces immune anergy with depletion ofA60-specific TL and activated Mphi. A60 protects mice against TB and cancer by inducing the synthesis of three lymphokines: interleukin 2 (IL-2), interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha). Tumour cells prevent A60-dependent synthesis of these lymphokines in vivo and in vitro.

CONCLUSION

These data provide some clues to immune surveillance and tumour escape mechanisms, as well as to the antituberculous and antineoplastic BCG action.

DNA cancer vaccines: a gene gun approach

A wide variety of approaches, all using gene transfer, have been tested experimentally as alternative means to vaccinate against cancer, either prophylactically or therapeutically. These include both ex vivo and in vivo gene transfer to tumour and/or non-tumour cells, using both viral and non-viral vectors. The transferred DNA has varied widely as well, including genomic or cDNA encoding tumour-associated or oncofoetal antigens, cytokines, histocompatibility molecules, and costimulatory molecules. Several of these approaches have been applied in human clinical trials. This review summarizes those approaches, then compares and evaluates various methods using cytokine DNA in conjunction with autologous tumour cells, with particular emphasis on particle-mediated gene transfer via a gene gun. Finally, prospects and needs for further development are discussed.

Augmentation of cisplatin cytotoxicity using cytokines on cervical carcinoma cell lines

We investigated whether the biological response modifiers like IFN-alpha, IFN-gamma and TNF-alpha could enhance the cytotoxic action of cisplatin on cervical carcinoma cell lines in vitro. The sensitivity of three cell lines SiHa, ME 180 and C33A to these agents was tested using colorimetric MTT assay as well as tritiated thymidine uptake. All the three cell lines demonstrated range of sensitivity to cisplatin and cytokines. Interferons and TNF when used in combination with lower dose of cisplatin showed a significant enhancement of cytotoxic action of the drug in all the cell lines. Thus these data indicate that cytokines in concert with the drug may have a potential to improve the 'in vivo' therapy in these patients.

Immunotherapy for peritoneal ovarian carcinoma metastasis using ex vivo expanded tumor infiltrating lymphocytes

Surgery and chemotherapy have contributed to a modest overall survival in patients with epithelial ovarian carcinoma. It is therefore important to pursue novel therapy strategies for this disease that are different from conventional chemotherapy. Tumor infiltrating lymphocytes (TILs) from patients with ovarian carcinoma may represent an active immune response of the host directed against the tumor cells. These TILs can be expanded in vitro in low concentrations of recombinant interleukin-2 (rIL-2) by a few thousandfold. The resulting T-cell lines comprise CD3+CD4+TCR alpha beta + or CD3+CD8+TCR alpha beta + cells, or mixtures of both. These T-cell lines may exhibit either tumor-specific cytotoxicity against autologous tumor cells, or produce cytokines (interferon-gamma, tumor necrosis factor, and granulocyte stimulating factor) either in antigen-dependent (tumor-specific) or an antigen-independent manner. T-cell lines exhibiting primarily autologous tumor-specific cytotoxicity were developed from approximately 50% of the patients. Blocking experiments using appropriate monoclonal antibodies revealed that the CD3/TCR complex on the effector cells and the MHC class I antigens on the tumor cells were involved in the cytolytic process. We have developed a four-step method for the expansion of TILs to large numbers (1 x 10(10) to 1 x 10(11)) sufficient for clinical trials in patients with ovarian cancer. We have conducted a pilot clinical trial to examine the feasibility and clinical effects of intraperitoneal TILs and low-dose rIL-2 in patients with advanced ovarian carcinoma who were refractory to platinum-based chemotherapy. More recently, procedures have been developed for obtaining large numbers of purified CD8+ rIL-2-expanded TILs for the treatment of patients with ovarian carcinoma. The evolution of clinical trials and correlative studies necessary to develop an effective adoptive immunotherapy approach were discussed.

Cytokine gene-modified vaccines in the therapy of cancer

Therapeutic strategies based on the insertion of cytokine genes into the genome of tumour cells, followed by vaccination with the resulting genetically modified, cytokine-producing cells, represent a new potential prospect for treatment of cancer patients. In this review, the concept of cytokine gene-modified cancer vaccines is discussed; the discussion is focused on the rationale, characterization, progress in the development, preclinical testing, and first clinical trials. An effort is made to analyse and integrate the results obtained in different experimental model systems in order to determine the needed approaches and directions for further research.

Modulation of cisplatin sensitivity and accumulation by interferon alpha-2A in human squamous carcinoma cell lines

This study was undertaken to elucidate the mechanism(s) of potentiation of cisplatin (CDDP) cytotoxicity by interferon alpha-2a (IFN alpha-2a) in human squamous carcinoma cell lines SCC-25 and SCC-4. IFN alpha-2a treatment significantly increased the cytotoxicity of CDDP in both cell lines in a dose-dependent manner. In SCC-25 cells, the cytotoxicity of CDDP was increased by about 2- and 4-fold, respectively, by treating the cells with 400 and 800 IU/ml IFN alpha-2a. Sensitivity of SCC-4 cells to CDDP was increased by about 3- and 7-fold, respectively, by 400 and 800 IU/ml IFN alpha-2a treatment. Drug uptake experiments revealed approximately 1.4- to 5-fold higher platinum accumulation in IFN alpha-2a-treated cells as compared to respective controls. Cellular levels of glutathione (GSH) and GSH transferase, which have been suggested to be important determinants of tumor cell sensitivity to CDDP, were not altered by IFN alpha-2a treatment in either of the cell lines. Northern blot analysis showed a moderate increase (about 30-40%) in the level of MT-IIA mRNA by IFN alpha-2a treatment in these cells. Our results suggest that IFN alpha-2a-mediated sensitization of SCC-25 and SCC-4 cell lines to CDDP in vitro may be due to an increase in intracellular platinum accumulation.

Interferon-alpha 2b, with or without prior hepatic artery embolization: clinical response and survival in mid-gut carcinoid patients. The Norwegian carcinoid study

BACKGROUND

Mid-gut carcinoid tumours often present with liver metastases, and survival has then been less than 2 years in earlier reports. We have evaluated the effects of interferon therapy on clinical response and survival, with or without hepatic artery embolization in these patients.

METHODS

In a prospective study 30 female and 12 male patients, aged 23 to 75 years, with mid-gut carcinoid tumours and liver metastases underwent surgery with removal of as much as possible of their primary tumour. If technically feasible, embolization of hepatic arteries was performed in the absence of contraindications. Seventeen patients were embolized, and all patients received interferon-alpha 2b treatment for 1 year. Response factors were computer tomography (CT) measurement of the largest liver metastasis and the 24-h urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA). After 12 months patients with objective response or stable disease either continued or withdrew from interferon therapy. Survival was estimated when all patients had been observed for at least 36 months.

RESULTS

Nine patients reduced the dose, and five withdrew from interferon treatment owing to side-effects the 1st year. Three patients died. Fifteen patients (39%) showed objective response 12 months after inclusion. Cumulative 5-year survival estimated from inclusion was 37.5% in all 42 patients but 71.4% in those who continued interferon therapy. The difference in survival between the interferon-treated and those who withdrew from interferon therapy at 12 months was significant when embolization was corrected for in a Cox model (p < 0.0125). The seemingly increased survival in embolized versus non-embolized patients did not reach statistical significance (p = 0.07).

CONCLUSION

Interferon induced an objective response in mid-gut carcinoid patients as judged by the 24-h urinary 5-HIAA excretion. Patients receiving continuous interferon therapy showed improved response and survival compared with patients who stopped the treatment. Regardless of medical therapy, more survivors and more responders, as evaluated from CT measurements, were found among the embolized patients than among the non-embolized. Embolization could, however, not be shown to have a significant effect on survival.

Nucleotide and predicted peptide sequence of feline interferon-gamma (IFN-gamma)

Interferon gamma is a pleiotropic cytokine which is now recognised as an important modulator of the immune response. We now report the cloning and sequencing of feline interferon gamma cDNA which was generated by the polymerase chain reaction. At the nucleotide level feline ifn-gamma shares 78% and 63% homology with human and murine cDNA equivalents. At the amino acid level the feline IFN-gamma shares 63% and 43% homology with human and murine homologs respectively.

Cytokine measurements and interpretation of cytokine assays in human disease

Cytokines are powerful mediator and communication molecules capable of regulating a wide spectrum of biologic functions, including immune responses. Although the role of cytokines in the pathogenesis of human disease is not yet understood, assays for cytokines have become a common feature in research and clinical laboratories. However, numerous pitfalls accompany measurements of cytokine levels in body fluids and of cytokine synthesis or gene expression in tissue. Interpretation of results obtained in cytokine assays, especially those performed with pathologic specimens, is fraught with difficulties. While cytokine assays are clearly of value in monitoring patients treated with recombinant cytokines or receiving anticytokine therapy, the clinical significance of cytokine assays is not yet fully established. In this review, some of the complexities associated with cytokine monitoring are discussed. The crucial importance of understanding cytokine biology for meaningful assay interpretation is emphasized.

Immunological fluctuations during intrathecal immunotherapy in three patients affected by CNS tumours disseminating via CSF

The immunological therapy of cancer has been proposed in a number of neoplasms (Borden, Sondel, 1989; Foon, 1989; Rosenberg, 1992) and has recently been adopted in the treatment of Central Nervous System (CNS) tumors in combination with conventional surgical and radiotherapeutical approach. In this context, loco-regional administration of immunomodulating agents (for instance in post-surgical cavity) allows to achieve much higher in situ concentrations than by systemic route. Since these treatments have potential adverse effects, careful assessment of clinical and immunological parameters in phase I trials is needed. CNS tumors disseminating via Cerebrospinal Fluid (CSF) pathways offer a stimulating opportunity for intrathecal immunotherapy. In this context, alpha-IFN and IL2 (alone or in combination with LAK cells) have been employed either loco-regionally or intrathecally (Merchant, Mc Vicar, Merchant & Young, 1992; Schiller, Hank, Storer, Borchert, Moore, Albertini, Bechhofer, Wesley, Brown, Bastin & Sondel, 1993). The rationale for the use of both these substances includes the known anti-tumor action of alpha-IFN (Mahaley, Urso, Whaley, Blue, Williams, Guaspari & Selker, 1985; Nagai, 1988) and the ability of r-IL2 to generate activated cells effective in lysing tumor cell targets (Hayes, Moore, Pierz, Chen, Da Rosso, Nirenberg & Allen, 1993). We treated 3 patients (2 affected by disseminating cerebellar medulloblastoma, 1 by disseminating thalamic glioblastoma) by intrathecal r-IL2 via recervoir. In the first 2 patients, this treatment was preceded by alpha-IFN (also intrathecally). Monitoring of immunological effects of the treatment schedule involved kinetics of CSF and serum TNF-alpha, IL2s and IL2R during the first day of r-IL2 treatment, as well as on day +2 and +4 of both r-IL2 cycles, and assessment of CSF cells, protein and CSF and PB NK cell activity and CD3-CD56+ cells during the course of all treatment cycles. We also assessed clinical and neuroradiological effects of immunotherapy.

Pharmacokinetics of intrapleural recombinant interleukin-2 in immunotherapy for malignant pleural effusion

BACKGROUND

The authors measured pharmacokinetic parameters before, during, and after immunotherapy by continuous intrapleural infusion of recombinant interleukin-2 (rIL-2) and correlated the resulting data with clinical effects in nine patients with malignant pleural effusion.

METHODS

The underlying disease was malignant mesothelioma in five patients and adenocarcinoma in four patients. Continuous intrapleural infusion of rIL-2 was performed for 5 days at 21 x 10(6) IU/m2/day. Maximum tolerated dose previously was determined to be 24 x 10(6) IU/m2/day in a Phase I study. Peak levels, the areas under the concentration curve (AUC), and drug half-lives were measured in pleural fluid and plasma samples collected at 0 (baseline), 12, 24, 48, 72, 96, and 120 hours during infusion and at 2, 6, 8, 32, 44, 56, 80, and 120 hours after the end of infusion.

RESULTS

High and prolonged intracavitary drug levels were achieved in all but two patients, with a statistically significant correlation between peak values and AUC. Four patients achieved objective responses according to World Health Organization criteria. Neither of the patients with undetectable rIL-2 levels had response to therapy. Serum rIL-2 levels were low regardless intrapleural levels. Mean AUC was lower in the plasma than in the pleural fluid.

CONCLUSIONS

This study demonstrates that continuous intrapleural infusion of rIL-2 is an active method of treatment for malignant pleural effusion. The low serum levels associated with this method greatly improve tolerance. The results also indicate that the concentration and duration of intrapleural rIL-2 levels may depend on the extent of pleural invasion. Additional study is needed to confirm this finding.

A simple method for the evaluation of receptor binding capacity of modified cytokines

We have developed a flow cytometric method to evaluate the binding of interleukin-2 analogues to receptors. The method relies on competition for binding between a fluorescein-conjugated monoclonal antibody (MoAb) directed against the human interleukin-2 receptor alpha chain (fluorescein isothiocyanate (FITC) anti-IL-2R) and the test protein. IL-2R positive cells are incubated with FITC-anti-IL-2R MoAb in the presence of native IL-2 or IL-2 iodinated by either the chloramine-T or the lactoperoxidase-glucose-oxidase method. The binding of IL-2 is indicated by decreased fluorescence. This method is suitable for measuring the binding capacity of modified IL-2 molecules and avoids the need for radioactive tracers. It provides a simple and reproducible technique, which can be extended readily to the study of the receptor binding capacity of cytokines conjugated with toxins, drugs or other molecules.

Peri-operative modulation of cellular immunity in patients with colorectal cancer

The peri-operative cellular immune response is depressed in patients with gastrointestinal cancer, a factor which may facilitate malignant dissemination. We have investigated the effects of peri-operative rIL-2 and a combination of rIL-2 and interferon-alpha (IFN-alpha) on both peripheral blood lymphocyte function and number in patients undergoing surgical resection for colorectal cancer. Fifty-two patients were randomly allocated to either control, rIL-2 or rIL-2 with IFN-alpha treatment arms. In vitro studies were performed pre-operatively and on post-operative days 1, 4, 7 and 10. Natural killer (NK) and lymphokine-activated killer (LAK) cell function were profoundly depressed in control patients (P < 0.001; P < 0.01), an effect abrogated in both treatment groups; indeed NK function was augmented in the rIL-2 and IFN-alpha group on the first post-operative day in association with an increase in the percentage of cells expressing CD16 and CD56 (P < 0.01). Flow cytometric analysis of lymphocyte subsets in the control group was unremarkable, except for an early post-operative fall in numbers of lymphocytes. Treatment with either rIL-2 or rIL-2 and IFN-alpha produced an initial profound reduction in T lymphocyte numbers, followed by a 'rebound' lymphocytosis of activated CD3+ T cells, as demonstrated by a significant increase in co-expression of CD25, CD38 and CD45RO. No significant differences were observed between either of the treatment groups. Adjuvant immunotherapy affects peri-operative anti-tumour immune responses, and this may influence long term outcome in patients undergoing surgery for gastrointestinal cancer.

Effects of cytokines on the pituitary-adrenal axis in cancer patients

Cytokines, which include interferons (IFNs), interleukins (ILs), and tumor necrosis factor (TNF), are immunoregulatory proteins produced by lymphocytes and inflammatory cells. Several cytokines, most noteworthy IFNs and ILs, stimulate glucocorticoid secretion. In this study, the effects of variable doses and repetitive administration of IFNs and TNF on secretion of pituitary hormones and cortisol were measured. Patients were given for a period of 15 days on alternating days injections of IFN-beta (IFN-beta ser), 90 or 450 x 10(6) IU, IFN-gamma, 0.1-100 x 10(6) IU, or TNF 125-275 micrograms/m2. Sixty to 120 min after IFN-beta ser injection median levels of cortisol, adrenocorticotropin (ACTH), prolactin (PRL), and growth hormone (GH) rose two-fold. Urinary free cortisol excretion increased significantly during the day following IFN-beta ser administration. IFN-gamma > or = 30 x 10(6) IU caused a comparable rise in plasma cortisol. TNF induced two- to four-fold increases in ACTH and cortisol. The fact that increased cortisol secretion was associated with a rise in the level of ACTH as well as PRL and GH suggests that the cytokines increased cortisol by stimulating the anterior pituitary. The hormonal response induced by cytokines was unrelated to their pyrogenic effect, undiminished with repetitive treatment, and not dose-dependent above a threshold level. These observations reinforce the concept of a physiologic link between the immune system and the hypothalamic-pituitary-adrenal (HPA) axis.

Biologic and immunologic approaches to comprehensive therapy for pediatric malignant conditions. Laboratory-clinical interaction

Cooperative integration of laboratory and clinical trial data has provided striking improvement in the treatment of pediatric malignant conditions over the last 2 decades. If attempts are made to individualize therapy to the specific disease and prognostic treatment subgroups for each pediatric malignant condition, the combination of surgery, radiation therapy, and chemotherapy can put the vast majority of patients into a complete clinical remission, with apparent cure for more than half of these patient. Depending on the disease type, treatment failure, when it occurs, is usually the result of recurrent, distant, metastatic disease that is refractory to prior treatment and simultaneously refractory to treatment approaches not yet used for the patient who has had a relapse. The clinical research challenge with these pediatric malignant neoplasms is to identify those children who are harboring microscopic amounts of residual tumor before their relapse and develop effective combined well-tolerated treatment approaches that can be initiated in those patients. These additional treatment approaches should complement rather than duplicate the biologic mechanisms that had been used to initiate remission to eradicate residual tumor without cross resistance. Ongoing laboratory and clinical research approaches are developing and testing the potential of biologic/immunologic therapeutics. The broad application of these principles to clinical oncology will be facilitated by the integrated laboratory-clinical testing that is being accomplished through cooperative pediatric clinical research trials.

[Autoimmune diseases and treatment with interferon-alpha: review of the literature apropos of a case of hyperthyroidism]

We report a case of thyrotoxicosis in a male patient under alpha-interferon (INF-alpha) therapy. Data from the literature show that treatment with IFN-a alone or combined with interleukin-2 (IL-2) can induce dysthyroidism (hypothyroidism, hyperthyroidism, thyroiditis). The frequency of dysthyroidism under INF-alpha therapy ranges from 10 to 40% depending on the authors. During combined INF-alpha and IL-2 therapy these figures reach 20 to 91%. The presence of anthyroid antibodies before treatment makes it more probable that dysthyroidism will occur. The administration of INF-alpha can exacerbate or induce various autoimmune diseases.

Antiproliferative effects of interferons -alpha and -beta in combination with 5-fluorouracil, cisplatin, and cis- and trans-retinoic acid in three human lung carcinoma cell lines

We assessed the antiproliferative effect of human recombinant interferon -alpha (IFN-alpha) or -beta in combination with 5-fluorouracil (5-FU), cisplatin, or cis- or trans-retinoic acid on two human nonsmall cell lung carcinoma cell lines (SK-LU-1 and SK-MES-1) and on one human small cell lung carcinoma cell line (NCI-H69). Results were obtained by direct cell count and/or by the clonigenic assay. The three cell lines differed in their sensitivities to the antiproliferative effects of the different agents. However, both NSCLC cell lines were more responsive to IFN-beta than to IFN-alpha. The SK-MES cell line was more resistant to both IFNs than the SK-LU-1. The NCI-H69 cells were resistant to all the drugs tested, except trans-retinoic acid. The dose and time of exposure were found to be important factors in the case of IFNs and cytotoxic agents, with lower surviving fractions obtained with the higher doses and longer exposures. This finding, however, did not hold true for the retinoic acids, which showed no antiproliferative effect. Within the sensitivity of our system, we did not identify any synergistic interaction in any of the cell lines with IFN-alpha or IFN-beta and 5-FU or cisplatin. A slight synergistic interaction was observed with IFN and cis- or trans-retinoic acid in the SK-LU-1 cell line which was not thought to be clinically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrapleural recombinant IL-2 in passive immunotherapy for malignant pleural effusion

The purpose of this phase 1 study was to determine the toxicity and effectiveness of recombinant interleukin-2 (RU 49637 Roussel Uclaf-France) administered by continuous pleural infusion for 5 days to patients with different histologic subtypes of pleural cancer. Incremental doses of rIL-2 from 3 x 10(6) to 24 x 10(6) were given via a thin catheter inserted into the homolateral pleural cavity. Patients were evaluated before treatment and 36 days after treatment by computed tomography scan and thoracoscopy with biopsy. Twenty-two patients with malignant pleural effusion (15 malignant pleural mesotheliomas, 6 adenocarcinomas, 1 squamous cell carcinoma) were treated. The maximum tolerated dose (MTD) of rIL-2, defined as the dose that produced grade 3 or greater toxic reactions in 50 percent of the patients, was 24 x 10(6) IU/m2/d. Although some side effects were encountered at any dose, tolerance was acceptable. The main side effect was fluid retention (8 of 22) which never exceeded 10 percent of body weight. Responses were achieved in 10 out of 22 patients with 1 complete remission (mesothelioma) and 9 partial remissions (3 adenocarcinomas and 6 malignant pleural mesotheliomas). Based on these results, we recommend that phase 2 studies using rIL-2 at a dose of 21 x 10(6) IU/m2/d via the intrapleural route be undertaken.

Immune changes in peripheral blood resulting from locally directed interleukin-2 therapy in squamous cell carcinoma of the head and neck

Interleukin-2 (IL-2) was administered locally by constant intra-arterial infusion in four escalating doses from 3 x 10(4)-3 x 10(7) IU/day to 12 patients with squamous cell carcinoma of the head and neck (SCCHN) in a phase I trial. Lymphocyte phenotypic markers and serum cytokine concentrations were measured over the course of treatment. Serum IL-1-alpha, -beta and IL-6 were not induced at any dose level. Tumour necrosis factor (TNF)-alpha was induced in the 2 patients who showed a clinical response (at the lowest dose) as well as in 4/10 of the non-responders. In addition TNF-beta was induced in 3/10 and IFN-gamma in 5/10 non-responders. Soluble IL-2 receptor concentrations were increased at the two higher doses. The highest dose of IL-2 produced a lymphocytosis after day 5 until the end of administration reflected by a general rise in lymphocyte phenotypic markers. CD25, CD3/HLA-DR and CD56 showed an additional upregulation not accounted for by the lymphocytosis with a suggestion of a bell-shaped dose-response curve for CD25 and CD3/HLA-DR. Administration of IL-2 in this manner has been shown to be well tolerated and has some anti-tumour activity at low doses, with little toxicity.

Absence of biological effects of orally administered interferon-beta ser

To assess biological effectiveness of interferon (IFN) administered orally, we measured serum IFN and several proteins and metabolites induced by IFN after oral administration of 2.5 mg or 7.5 mg of recombinant IFN-beta ser to 6 healthy volunteers. These IFN-induced metabolites, beta 2-microglobulin, and neopterin in serum, and 2',5'-oligoadenylate (2-5A) synthetase in peripheral blood mononuclear cells, are more sensitive to the presence of IFN than bioassay of IFN in serum. Up to 48 h after oral IFN was administered, serum IFN, beta 2-microglobulin, neopterin, or 2-5A synthetase were not generally increased compared to pretreatment levels, indicating that oral IFN had no significant biological effects.