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Biomedical subjects

R G Fenton

Publications and source records attributed to R G Fenton.

At least 37 records · Page 2Linked to original sources

Phase I study of subcutaneously administered interleukin-2 in combination with interferon alfa-2a in patients with advanced cancer.

PURPOSE: Although high-dose interleukin-2 (IL-2) can produce durable remissions in a subset of responding patients with renal cell carcinoma (RCC), this occurs in the setting of significant toxicity. The purpose of this study is to define the maximum-tolerated dosage (MTD) of IL-2 and interferon alfa-2a (IFN alpha-2a) that can be administered chronically on an outpatient basis. PATIENTS AND METHODS: Fifty-three patients with advanced cancer of variable histology with good prognostic features were treated in six cohorts. Patients in cohorts one through five received IL-2 (1.5 or 3.0 x 10(6) million units (mU)/m2) Monday through Friday and IFN alpha-2a (1.5 or 3 x 10(6) mU/m2) daily for a 4-week cycle. In cohort six, IFN alpha-2a was given three times a week. Immunologic monitoring, including serum levels of soluble IL-2 receptor (sIL-2R) and neopterin, flow cytometry, and natural killer cell (NK) activity, were measured. Patients were evaluated for toxicity, response, and survival. RESULTS: Almost all patients developed grade I/II toxicities commonly associated with cytokine therapy. Symptoms were most severe with the first treatment of each week. Dose-limiting toxicities included grade III fatigue, hypotension, and creatinine elevations. The MTD was 1.5 mU/m2 daily x 5 given subcutaneously repeated weekly for IL-2 and 1.5 mU/m2 daily subcutaneously (dose level 3) for IFN. Six of 25 assessable patients with RCC (24%) achieved a partial response (PR), including four of eight patients who were previously untreated. There were no objective responses in patients with other tumors, including 12 melanoma patients. CONCLUSION: IL-2 and IFN alpha-2a can be given with tolerable toxicities on an outpatient basis and shows significant activity in patients with metastatic RCC.

Adult↗

Induction of T-cell immunity against Ras oncoproteins by soluble protein or Ras-expressing Escherichia coli.

BACKGROUND: Point mutations in the ras proto-oncogene that activate its oncogenic potential occur in approximately 30% of human cancers. Previous studies have demonstrated that T-cell immunity against some forms of mutant Ras proteins could be elicited, and some effectiveness against tumors expressing activated Ras has been reported. PURPOSE: The goal of this study was to determine if immunization of mice with two forms of mutant Ras protein can induce high levels of Ras mutation-specific T-cell immunity in vitro and tumor regression in vivo. METHODS: Mice (BALB/c or C3H/HeJ) were immunized subcutaneously at 2-week intervals with purified Ras oncoproteins mixed with the immunologic adjuvants Antigen Formulation or QS-21, both of which have been shown to enhance the induction of T-cell-mediated immunity when included as components of soluble protein vaccines. In some experiments, mice were immunized directly with heat-killed Escherichia coli that had been induced to express one of the mutant Ras proteins. Spleen cells plus lymph node cells from Ras-immunized mice were tested in vitro for lysis of syngeneic Ras-expressing tumor cells and proliferation in response to mutant Ras peptides. For some of the cytolytic activity experiments, the spleen cells were grown under TH1 conditions (growth in presence of interleukin 2, interferon gamma, and an antibody directed against interleukin 4 to stimulate a cell-mediated immune response) or TH2 conditions (growth in presence of interleukins 2 and 4 to stimulate a humoral immune response). The specificity of immunity was examined in vivo by challenge of Ras-immunized mice with syngeneic tumor cells expressing mutant Ras oncoproteins (HaBalb, i.e., BALB/c mouse cells expressing Ras with arginine substituted at amino acid position 12 [Arg 12 Ras]; C3HL61, i.e., C3H/HeJ mouse cells expressing Ras with leucine substituted at position 61 [Leu 61 Ras]). Ten mice per group were used in each experiment. RESULTS: Proliferative and cytolytic T-cell responses directed against the Arg 12 Ras protein were generated in BALB/c mice, resulting in protection against challenge with cells expressing Arg 12 Ras and therapeutic benefit in mice bearing established tumors expressing this protein. In C3H/HeJ mice, high levels of cytolytic and proliferative responses were induced against Leu 61 Ras. Immunization with heat-killed E. coli genetically engineered to express Leu 61 Ras also led to the induction of anti-Ras T-cell immunity. T cells grown under TH1 conditions were cytolytic against Ras-transformed tumor cells, whereas those grown under TH2 conditions were not. CONCLUSIONS: Immunization as described here leads to Ras mutation-specific antitumor immunity in vitro and in vivo, with therapeutic efficacy in an established tumor model.

Animals↗

Myositis associated with interleukin-2 therapy in a patient with metastatic renal cell carcinoma.

BACKGROUND: Interleukin-2 (IL-2) has been used successfully in the treatment of some patients with metastatic renal cell carcinoma and melanoma, with a partial response rate of 15%-20%. It produces a well documented spectrum of side effects. Autoimmune diseases have been associated with IL-2 immunotherapy and the development of autoimmune thyroiditis may correlate with antitumor clinical response. METHODS: A patient with metastatic renal cell carcinoma is described who developed a polymyositis-like myopathy after an autologous tumor vaccine and IL-2 therapy. RESULTS: The patient had a delayed response for 15 months after developing this previously unreported toxicity. CONCLUSIONS: To the authors' knowledge, this represents the first reported case of necrotizing myositis in association with IL-2 therapy. Subsequent continuous partial response of the advanced malignancy was observed for 15 months. In this case, IL-2 may have broken tolerance to both normal muscle cells and tumor cells.

Biopsy↗

CD4+ T-cell immunity to mutated ras protein in pancreatic and colon cancer patients.

Mutated p21 ras proteins contain single substituted amino acid residues and represent cancer-specific proteins. The current study examined whether primed T cell immunity to mutant p21 ras proteins and/or peptides can be detected in patients with pancreatic or colon cancer. Studies focused on the aspartic acid substitution in amino acid position 12 (denoted D12) as the commonest mutation in gastrointestinal malignancy. Peripheral blood lymphocytes from patients or normal individuals were tested for the ability to proliferate in response to normal or mutated ras peptides or proteins. T-cell responses were defined as a stimulation index of > 2.0. Results showed that 7 of 16 (44%) pancreatic cancer patients responded to ras-D12 peptide. Responses to ras-D12 protein were studied in only the last four patients that responded to D12 peptides. Three of the 4 patients that responded to ras-D12 peptide showed a substantial response to p21 ras-D12 protein (stimulation indices of 12, 8, and 24). Specificity was validated by examining responses to normal and alternate ras peptides and proteins. T-cell responses to ras-D12 peptides were detected in only 2 of 25 (8%) colon cancer patients. None of 11 normal individuals tested had positive responses to normal or mutant ras p21 proteins and/or peptides. Thus, CD4+ T-cell immunity to the mutated segment of ras protein is present in some patients with gastrointestinal cancer.

Amino Acid Sequence↗

CD28:B7 interactions promote T cell adhesion.

CD28 activation by antibody-mediated ligation has been shown to provide an important co-stimulatory signal for T cell adhesion to purified protein ligands. However, the effect of CD28 ligation by one of its natural ligands, B7.1, on T cell adhesion to other cells has not been studied. Therefore, in the present manuscript, we characterized the adhesive interactions between human T cells and B7.1-transfected major histocompatibility complex class II+ and class II- melanoma cells. In our studies, human T cells and T cell clones adhered to B7.1-transfected melanoma cells, but not to untransfected parental cells. The adhesive reaction in this model was rapid, occurring within 15 min, and was inhibited by anti-B7.1 antibody and soluble CTLA-4 immunoglobulin. Antibody inhibition studies demonstrated that adhesion between T cells and B7.1-transfected melanoma cells was mediated by interactions between LFA-1:ICAM-1 and CD2:LFA-3. Inhibition by pharmacological agents demonstrated that the CD28-induced adhesion required specific intracellular signaling events. A protein kinase C inhibitor, staurosporin, significantly inhibited T cell binding to transfected melanoma cells, while cyclosporin A and wortmannin, an inhibitor of phosphatidylinositol-3-kinase, did not. These results suggest that the presence of B7 on various cell populations may activate lymphocytes to adhere better, thus promoting activation, cytolysis, and migration.

Abatacept↗

Cellular and molecular studies in the treatment of murine renal cancer.

Antigen-nonspecific approaches to the use of BRMs for cancer treatment have resulted in only limited success to date. In particular, the use of large numbers of adoptively transferred, broadly cytotoxic LAK cells in combination with IL-2 has been effective for only small subsets of cancer patients. Recent demonstrations of T-lymphocyte-mediated antigen-specific responses against some human tumors, and the more potent effects of these cells in preclinical models, have refocused much of the dialogue for biological therapy to potentiation of T-lymphocyte-mediated antitumor effects. Our studies are using the well-characterized Renca murine renal cancer model to study the induction of antitumor T-lymphocyte-mediated responses, the mechanisms by which positive effects are achieved, and the reasons why T lymphocytes in tumor-bearing mice may not respond as predicted. One possible reason why T-lymphocyte responses may not be triggered easily by tumors could be an impairment of critical nuclear transcription factors. We also are studying two approaches for stimulating T-cells in tumor-conditioned hosts. (1) We have shown that IL-7 has potent costimulatory effects on T cells as well as some antitumor effects. (2) We are developing a comprehensive vaccine-type gene therapy approach whereby T cells and antigen-presenting dendritic cells are recruited through the use of antigen, chemokines and GM-CSF. Studies are in progress to determine whether the activity of these recruited cells can then be potentiated by Renca or fibroblast transfectants that express T-cell costimulatory cytokines (IL-2, IL-4, IL-7, or IL-12). This approach should optimize both MHC class I- and class II-dependent pathways for induction of T-lymphocyte-mediated responses to cancer, and perhaps overcome tumor-induced impairments in the T lymphocyte function.

Animals↗

Cloning and analysis of MAGE-1-related genes.

The spectrum of MAGE gene expression in the human melanoma cell line DM150 was examined using reverse transcription polymerase chain reaction and cDNA cloning. We have isolated five full-length cDNAs from DM150 which were identified as MAGE-1, MAGE-3, MAGE-12 and two previously undescribed MAGE genes, MAGE-3b and MAGE-X2. DNA sequence analysis of the coding regions of the MAGE-3b and MAGE-X2 genes revealed 83% and 88% identity with MAGE-1, while MAGE-3b was 98% homologous with the full length MAGE-3 clone. The predicted amino acid sequences of MAGE-X2 and MAGE-3b contain consensus HLA-A1 peptide binding motifs, suggesting that, like MAGE-1, they may code for tumor-associated antigens. In addition, a nonamer peptide encoded by both the MAGE-3 and MAGE-12 genes was shown by direct binding studies to contain an aggretope for HLA-A2.

Amino Acid Sequence↗

Cytotoxic T-cell response and in vivo protection against tumor cells harboring activated ras proto-oncogenes.

BACKGROUND: Activated forms of the ras proto-oncogene have been found in approximately 30% of human malignancies, including pancreatic, colon, and lung adenocarcinomas. Ras oncoproteins arise by somatic mutation and contain amino acid changes at residues 12, 13, or 61, thus generating unique tumor-specific proteins that are attractive targets for cancer therapy. PURPOSE: The goal of this study was to determine whether vaccination with mutant Ras protein could lead to the generation of cytotoxic T lymphocytes (CTLs) specific for the mutant epitope and to protection against challenge with tumor cells expressing the mutant oncoprotein. METHODS: To determine a methodology for generating CTL responses following immunization with soluble protein, ovalbumin was used as a model tumor antigen. C57BL/6 mice were immunized with soluble ovalbumin administered intraperitoneally at 2-week intervals or with intravenous injection of ovalbumin or osmotically loaded splenocytes. Immunized mice were challenged with E.G7 cells (which express a transfected ovalbumin gene), and tumor growth was monitored. Generation of ovalbumin-specific CTLs was determined by 51Cr release assays. Purified wild-type or mutant H-Ras proteins (containing single amino acid substitutions at position 12 converting Gly to Arg or Val) were used to immunize BALB/c mice intraperitoneally. Ras-immunized mice were challenged with tumor cells containing Arg 12 or Val 12 mutations or not harboring mutant forms of Ras. Cytolytic and proliferative responses to mutant forms of Ras were studied, and the effects of in vivo depletion of CD4+ or CD8+ T lymphocytes were determined. RESULTS: In vivo challenge with E.G7 showed that intraperitoneal immunization with soluble ovalbumin was as effective as osmotic loading, resulting in long-term disease-free survival of some mice and the development of ovalbumin-specific CTLs. Immunization with Arg 12 Ras led to disease-free survival in nine of 10 animals challenged with tumor cells containing an Arg 12 mutation, while no protection was afforded against tumors expressing other forms of Ras or other oncogenes. Splenocytes from BALB/c mice immunized with Arg 12 Ras demonstrated cytolytic activity specific against tumor cells expressing Arg 12 Ras, with most of this activity residing in the CD8+ subset. Mutation-specific proliferation to Arg 12 Ras peptides was also observed. Immunization with Val 12 Ras did not elicit detectable Val 12-specific immunity. CONCLUSIONS: Antigen-specific CTLs can be induced following intraperitoneal immunization of mice with purified, soluble proteins. For both ovalbumin and Arg 12 Ras, specific in vivo protection against tumor cell challenge was observed.

Amino Acid Sequence↗

The effects of treatment with interleukin-1 alpha on platelet recovery after high-dose carboplatin.

BACKGROUND: Thrombocytopenia is a frequent side effect of cancer chemotherapy and commonly limits attempts to escalate drug doses. To determine whether interleukin-1 alpha could ameliorate carboplatin-induced thrombocytopenia, we combined it with high-dose carboplatin in 43 patients with advanced neoplasms. METHODS: High-dose carboplatin (800 mg per square meter of body-surface area) was administered alone to a control group. Subsequent patients were randomly assigned to receive the same dose of carboplatin with interleukin-1 alpha, administered either before or after carboplatin. Interleukin-1 alpha was given intravenously at a dose of 0.03, 0.1, or 0.3 microgram per kilogram of body weight per day for five days. RESULTS: Carboplatin alone consistently produced thrombocytopenia with a median nadir of 19,000 platelets per cubic millimeter and a median of 10 days with less than 100,000 platelets per cubic millimeter. All 15 patients receiving interleukin-1 alpha before carboplatin had similar findings. In contrast, 5 of the 15 patients given one of the two higher doses of interleukin-1 alpha after carboplatin had minimal thrombocytopenia (nadir, 91,000 to 332,000 platelets per cubic millimeter). In the 10 patients given 0.3 microgram of interleukin-1 alpha per kilogram after carboplatin treatment, the platelet count recovered to 100,000 per cubic millimeter significantly earlier than in either the control group (P = 0.002) or the patients who received interleukin-1 alpha before carboplatin (P = 0.003), with the median times to recovery in the three groups being 16, 21, and 23 days, respectively. At the highest dose of interleukin-1 alpha, toxicity was substantial (but reversible), requiring inpatient support for hypotension, supraventricular arrhythmias, and pulmonary-capillary leak. CONCLUSIONS: Interleukin-1 alpha can accelerate the recovery of platelets after high-dose carboplatin therapy and may be clinically useful in preventing or treating thrombocytopenia induced by chemotherapy.

Adult↗

Dose-related immunologic effects of levamisole in patients with cancer.

PURPOSE: This phase I study was conducted to determine the maximum-tolerated dose (MTD) and the immunologic properties of levamisole in cancer patients when administered alone and in combination with interferon gamma (IFN-gamma). PATIENTS AND METHODS: Twenty patients with advanced cancer and 36 patients with completely resected melanoma (n = 33) or renal cell cancer (n = 3) received levamisole orally every other day for six doses at 1.0, 2.5, 5.0, or 10.0 mg/kg. Ten days later, patients restarted levamisole and began IFN-gamma 0.1 mg/m2 by subcutaneous injection every other day. Blood samples were collected for measurement of neopterin and soluble interleukin-2 receptor (sIL-2R), and for flow-cytometric analysis. RESULTS: The MTD of levamisole was 5 mg/kg, and this was not changed by the addition of IFN-gamma. Dose-related increases in serum levels of neopterin and sIL-2R were noted. Multiple doses of > or = 5 mg/kg of levamisole were required to elicit immune changes, which were more prominent in patients with minimal tumor burdens. Increased expression of CD64 and class I and class II major histocompatibility antigens on monocytes was also observed. The combination of IFN-gamma and levamisole did not result in greater immunologic effects than those observed in previous trials of IFN-gamma alone. CONCLUSION: Levamisole induces dose-related immunologic changes in patients with large or minimal tumor burdens. These changes may be involved in the beneficial effects noted in recent adjuvant trials of levamisole. Ongoing clinical trials should correlate immune changes with response, and trials exploring different schedules of administration using higher, more immunologically active, doses of levamisole should be performed.

Adult↗

Treatment of cancer patients with ex vivo anti-CD3-activated killer cells and interleukin-2.

PURPOSE: This study describes the physiologic and biologic effects resulting from the adoptive transfer of ex vivo anti-CD3-stimulated T-killer cells (T-AK) to patients with advanced cancer in combination with interleukin-2 (IL-2). METHODS: Autologous peripheral-blood mononuclear cells were obtained by leukapheresis and stimulated ex vivo with anti-CD3. The stimulated cells were reinfused at one of three dose levels on the next day (5 x 10(9), 7.5 x 10(9), and 1 x 10(10)). Cell administration was followed by IL-2 given by bolus and continuous infusion (1.5 x 10(6) U/m2 and 3.0 x 10(6) U/m2, respectively) for 7 days, or continuous infusion alone (3.0 x 10(6) U/m2) for 14 days. RESULTS: Pronounced leukocytosis and atypical lymphocytosis were observed with individual values as high as 80,000 and 50,000 cells/microL, respectively. The other major clinical sequelae included a marked lactic acidosis with bicarbonate levels as low as 4.0 mmol/L in some patients, and prolongation of the prothrombin time (PT) and partial thromboplastin time (PTT) due to decreases in clotting factors VII, IX, and X. Antithrombin III levels were also reduced. Hypotension associated with increased serum nitrate and neopterin levels was observed. These toxicities were accompanied by increases in hepatocellular enzymes and creatinine previously described with IL-2. These events occurred at a time when the number of circulating T-AK cells reached their peak. The amount of bolus IL-2 correlated with increases in WBC count (P = .0311), atypical lymphocytes (P = .0241), PT (P = .0006), and PTT (P = .0122). CONCLUSION: Substantial in vivo expansion of activated T lymphocytes was induced by a protocol combining ex vivo activation of peripheral-blood cells with anti-CD3 antibody followed by adoptive transfer and IL-2 administration. The synchronous expansion of these T cells superimposed on diminished liver and kidney function from IL-2 can cause profound but reversible metabolic changes.

Acidosis↗

Intensive therapy with cisplatin, interleukin-2 and interferon-alpha-2a in patients with metastatic melanoma. A phase II Study.

OBJECTIVE: Based upon their individual clinical activity and combined effects in animal models or in vitro, we wished to evaluate a regimen of cisplatin, interferon-alpha, and IL-2 in patients with metastatic melanoma. DESIGN: Phase II pilot study. SETTING: Referral-based US Government clinical research unit. PATIENTS: Nine patients with metastatic malignant melanoma. INTERVENTION: Cisplatin 75-100 mg/m2 was administered intravenously over 30 minutes on days 1 and 8. Interferon-alpha 2a 5 Mu/m2 body surface area (BSA) was given subcutaneously for 4 days beginning 1 day before each dose of cisplatin. Beginning on day 15 and day 22, IL-2 was administered by intravenous continuous infusion at 3 Mu/m2 BSA/d for 96 hours and by daily intravenous bolus concurrent with daily subcutaneous doses of interferon-alpha 2a. MAIN OUTCOME MEASURES: Antitumor response and toxicities. RESULTS: The study was stopped due to renal and hematopoietic toxicity and severe, delayed nausea and vomiting associated with the cisplatin-interferon treatment. Three of 9 patients achieved a partial response (duration 2.5, 4, 14+ months), and an additional patient had a 50% reduction in measurable tumor volume before undergoing resection of residual disease. Overall response rate was 45%. CONCLUSION: This regimen was associated with excessive toxicity, and the lack of complete responses in a patient cohort with favorable characteristics for response (good performance status, predominance of skin and lymph node metastatic sites) suggests that it had no advantage over less toxic treatment regimens. REGISTRATION: National Cancer Institute/Cancer Therapy Evaluation Program T89-0137.

Adult↗

Pilot study of interleukin-2 and lymphokine-activated killer cells combined with immunomodulatory doses of chemotherapy and sequenced with interferon alfa-2a in patients with metastatic melanoma and renal cell carcinoma.

BACKGROUND: Experiments in animal tumor models suggest that the antitumor effects of interleukin-2 (IL-2) or IL-2 in combination with lymphokine-activated killer (LAK) cells can be enhanced by chemotherapy agents such as cyclophosphamide or doxorubicin or by the biologic agent interferon alpha. PURPOSE: We determined the toxicity and clinical response rate of an IL-2-LAK cell regimen modified by the addition of moderate, immunomodulatory doses of chemotherapy and sequenced with interferon alfa-2a (IFN alpha-2a) in patients with metastatic melanoma and renal cell carcinoma. METHODS: IL-2 (3-6 million units/m2 per day) was administered by continuous infusion on days 0-5 and days 11-16. LAK cells were infused on days 11 and 12 or on days 11, 12, and 14. Low doses of cyclophosphamide (300 mg/m2) and doxorubicin (25 mg/m2) were given on day 9 before the LAK cell infusions. Following the IL-2-LAK cell infusion, IFN alpha-2a (12 million units/m2) was administered for a total of nine doses to complete a cycle of treatment. A total of 89 patients were enrolled in the study. RESULTS: For each histology, there were eight partial responses in 40 assessable patients, for an overall response rate of 20% (90% confidence interval = 10%-33%). The median response duration was 5 months, although two patients with renal cell carcinoma and one patient with metastatic melanoma had almost complete disappearance of tumor and are still responding after 26+, 22+, and 26+ months, respectively. Toxic effects were severe in patients receiving the highest dose of IL-2 administered in this study and similar to those reported with other high-dose IL-2-LAK cell regimens. Although toxic effects were completely reversible in most patients, there were four treatment-related deaths. CONCLUSIONS: This regimen is active in patients with metastatic melanoma and renal cell carcinoma and produces meaningful responses in a small percentage of these patients; however, it is not clear whether cyclophosphamide, doxorubicin, and IFN alpha-2a as used in this protocol appreciably augmented the antitumor activity of the IL-2-LAK cell regimen.

Adult↗

Regulation of intracellular actin polymerization by prenylated cellular proteins.

Posttranslational modification by covalent attachment of polyisoprene intermediates to a carboxyterminal CAAX-box motif is required for the biologic function of proteins such as p21ras, the supergene family of ras-related proteins, nuclear lamins, and subunits of heterotrimeric G-proteins. Cells grown in the presence of lovastatin, which inhibits HMG-CoA reductase and prevents synthesis of intermediates required for protein prenylation, develop a round, refractile morphology. Our data indicate that this is due to the selective loss of actin cables without gross changes in the microtubular lattice or intermediate filament structure. Microinjection of a competitive peptide inhibitor of protein prenyltransferases into the cytoplasm of cells induces an identical change in morphology with loss of actin cables. Mevalonate (MVA) reverses the lovastatin-induced morphologic change by inducing a rapid repolymerization of actin cables with coincident reversion to the flat morphology. Furthermore, microinjection of farnesyl-pyrophosphate or geranylgeranyl-pyrophosphate into lovastatin-treated cells also results in rapid morphologic reversion. The morphologic reversion induced by MVA requires the presence of serum, and is independent of extracellular calcium. The addition of cycloheximide to the growth medium prevents lovastatin-induced loss of actin cables, and causes morphologic reversion of lovastatin-treated cells by a mechanism that is independent of MVA. A1F4- induces morphologic reversion in a manner indistinguishable from MVA. These data indicate that prenylated protein(s) play a critical role in regulating the state of intracellular actin, and that GGPP can rescue the lovastatin-induced morphologic phenotype in the absence of upstream intermediates of cholesterol biosynthesis. We have begun to dissect the signaling events that mediate this pathway.

Actin Cytoskeleton↗

The toxic and hematologic effects of interleukin-1 alpha administered in a phase I trial to patients with advanced malignancies.

PURPOSE: A phase I trial was undertaken because interleukin-1 alpha (IL-1 alpha) possesses antiproliferative, immunostimulatory, antiinfection, myeloprotective, and myelorestorative properties that could be beneficial in cancer treatment. PATIENTS AND METHODS: In this phase I trial, IL-1 alpha was administered intravenously (IV) during a 15-minute period daily for 7 days to patients with advanced solid malignancies. RESULTS: The maximum-tolerated dose (MTD) of IL-1 alpha alone was 0.3 microgram/kg. A second group of patients received indomethacin plus IL-1 alpha based on preclinical studies, which indicated that indomethacin could abrogate IL-1 alpha-induced hypotension; however, the MTD of IL-1 alpha plus indomethacin was 0.1 microgram/kg lower than IL-1 alpha alone. Fever, chills, headache, nausea, vomiting, and myalgia were common but were not dose-limiting. Hypotension resulted from a marked decrease in systemic vascular resistance and required pressors at 0.3 and 1.0 micrograms/kg IL-1 alpha. Dose-limiting toxicities included hypotension, myocardial infarction, confusion, severe abdominal pain, and renal insufficiency. IL-1 alpha treatment caused a significant, dose-related increase in the total WBC count (mainly segmented neutrophils and neutrophilic bands). Bone marrow cellularity increased because of enhanced numbers of relatively mature myeloid cells and megakaryocytes. Platelet counts decreased during therapy but were significantly elevated above baseline values 1 to 2 weeks posttreatment; this may have been an effect of IL-6 that was shown to be induced by IL-1 alpha treatment. Significant increases in triglycerides, cortisol, C-reactive protein, thyroid-stimulating hormone and decreases in cholesterol, testosterone, and protein-C were observed with treatment. CONCLUSION: We conclude that at doses of IL-1 alpha that can be given safely to cancer patients, significant, potentially beneficial hematopoietic effects occur.

Adult↗

Isotypic exclusion of gamma delta T cell receptors in transgenic mice bearing a rearranged beta-chain gene.

The rearrangement of T cell antigen receptor beta- and gamma-chain gene segments was studied in transgenic mice that bear a functional beta-chain gene. Virtually all CD3-positive T cells derived from transgenic mice express beta chains containing the transgene-encoded V beta 8.2 variable region on their surfaces and do not express endogenous beta-chain variable regions. Expression of endogenous V beta genes is inhibited at the level of somatic recombination during thymic ontogeny. Furthermore, rearrangements of the TCR gamma-chain genes are also markedly inhibited in these transgenic animals. Hence expression of the TCR beta transgene has led to allelic exclusion of alpha beta receptors and isotypic exclusion of gamma delta T cell receptors.

Alleles↗