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Biomedical subjects

F R Aronson

Publications and source records attributed to F R Aronson.

25 records · Page 2Linked to original sources

Metastatic malignant melanoma treated with combined bolus and continuous infusion interleukin-2 and lymphokine-activated killer cells.

Fifty patients with advanced melanoma received high-dose bolus and continuous infusion interleukin-2 (IL-2) with lymphokine-activated killer (LAK) cells in an attempt to improve the therapeutic index of this active but toxic therapy. Treatment began with up to nine bolus doses of IL-2 administered over 3 days. After 1 day of rest, patients underwent daily leukapheresis for 4 days, and the leukocytes were cultured with IL-2 in vitro to prepare LAK cells. Continuous infusion IL-2 was begun 1 day after the last leukapheresis and continued for up to 148 hours; LAK cells were administered on days 1, 2, and 4 of the infusion. Responding patients were eligible to receive up to two additional cycles of therapy at 3-month intervals. Most patients completed each cycle without dose reduction. One patient had a complete response and six patients had partial responses (14% response rate). The complete responder and three of the partial responders (8%) remain free from disease progression with follow-up of 21 to 24 months. Of these four patients with durable remissions, one had extensive liver and lymph node metastases, one had lymph node, pleural, and parenchymal lung metastases, and two had disease limited to lymph nodes or subcutaneous tissues. Seventeen patients (34%) required pressors for hypotension, three patients (6%) developed hemodynamically significant arrhythmias, and six patients (12%) developed dyspnea at rest, but none required intubation and there were no treatment-related deaths. Unacceptable toxicity developed in two patients during bolus IL-2 administration and therapy was aborted; both returned to baseline status within 4 days of discontinuing IL-2. Fever, oliguria, and elevated creatinine or transaminase levels occurred frequently but were also transient. Despite less frequent severe toxicity with this modified regimen, these results confirm the ability of IL-2 and LAK cell therapy to induce durable remissions in some patients with advanced melanoma.

Adult↗

Activated endothelial cells resist lymphokine-activated killer cell-mediated injury. Possible role of induced cytokines in limiting capillary leak during IL-2 therapy.

We previously demonstrated that IL-2 promotes the adhesion of NK cells to endothelial cells (EC) and that EC are readily lysed by lymphokine-activated killer (LAK) cells in vitro, suggesting that cell mediated endothelial injury may contribute to the capillary leak syndrome observed in patients treated with IL-2. In this investigation, we sought to determine the effects of EC activation on the in vitro susceptibility of EC to LAK cell-mediated cytolysis. Despite increased binding of CD16+ lymphocytes to TNF-activated EC monolayers, prior exposure of EC to any of several IL-2-inducible cytokines including TNF-alpha, IL-1 beta, and IFN-gamma not only failed to render the EC more vulnerable to cytolysis but increased their resistance to LAK cells in 111Indium release cytolysis assays. This decrement in susceptibility to cytolysis resulting from prior exposure to cytokines preceded any detectable increase in HLA class I or II Ag expression. In cold target competition experiments with LAK cell effectors and radiolabeled K562 target cells, TNF-primed EC were no more competitive than unstimulated EC, and in assays with unstimulated PBMC effectors, the addition of unlabeled TNF-activated EC actually increased the cytolysis of the radiolabeled tumor cells. The effects of various cytokines and lymphocyte preparations on EC permeability were also evaluated. In these experiments, saphenous vein EC were cultured on porous filter disks, exposed to cytokines or lymphocytes, and the diffusion of 125I-BSA through the filters was then measured. Exposure to IL-2, IFN-gamma, or TNF-alpha did not increase the diffusion of the BSA through the EC-coated filters, whereas LAK cells markedly increased their permeability. Consistent with the results of the cytolysis assays, pretreatment of the EC with TNF, IL-1, or IFN-gamma diminished the LAK cell-induced increase in BSA diffusion. These results suggest that although circulating IL-2-inducible cytokines such as TNF and IFN-gamma may activate EC in vivo and contribute to lymphocyte margination and lymphopenia, they may not be directly responsible for the IL-2-induced capillary leak syndrome and may actually protect EC from LAK cell-mediated injury.

Antigens, Differentiation↗

IL-2 stimulates the production of IL-1 alpha and IL-1 beta by human peripheral blood mononuclear cells.

Human PBMC were cultured in medium containing human rIL-2, and the supernatants and cell lysates were analyzed for IL-1 alpha and IL-1 beta using specific RIA. IL-2, but not the excipient detergents included in the rIL-2 preparation, induced the synthesis of both cytokines. The concentrations of IL-1 alpha and IL-1 beta in the cell lysates and supernatants depended on both the concentration of rIL-2 in the culture medium and the duration of the incubation. After 24 h of stimulation, IL-2-induced IL-1 alpha remained almost entirely cell-associated. In contrast, IL-1 beta was present in both cell lysates and supernatants and was more abundant in the latter. SDS-PAGE analysis after radioimmunoprecipitation with anti-IL-1 antibodies indicates that cell-associated IL-1 resulting from IL-2 stimulation was in the form of the 35 kDa IL-1 precursor whereas secreted IL-1 was almost entirely in the form of the mature 18 kDa product. Depletion of monocytes from the PBMC culture substantially reduced IL-2-induced IL-1 production. In addition, Leu M3+ monocytes obtained through FACS, but not CD16+ NK cells, produced both IL-1 alpha and IL-1 beta in response to IL-2. The low level of endotoxin present in the IL-2 preparation used in our studies and the selective inhibition by polymyxin B of LPS-induced, but not IL-2-induced, IL-1 production by PBMC indicate that IL-2-induced IL-1 production was not due to endotoxin contamination. Furthermore, an anti-IL-2 antiserum selectively inhibited IL-1 production in response to IL-2 stimulation. We conclude that IL-2 is a potent inducer of IL-1 synthesis and secretion in vitro and propose that IL-1 may be generated in vivo in patients undergoing IL-2 immunotherapy.

Cell Separation↗

IL-2 rapidly induces natural killer cell adhesion to human endothelial cells. A potential mechanism for endothelial injury.

NK cells promptly disappear from the circulation of patients treated with high dose i.v. rIL-2. To further study this process, we evaluated the effects of IL-2 (1000 U/ml) on normal donor PBMC incubated for 1 h on cultured human saphenous vein endothelial cells (EC). Although the NK activity of non-adherent PBMC recovered from flasks coated only with fibronectin increased in the presence of supplemental IL-2, the activity of cells recovered from flasks coated with EC decreased when IL-2 was added to the medium. The percentage of NK (CD16+) cells among the EC-non-adherent PBMC was reduced relative to that of the input cells when IL-2 was added. The percentage of CD16+ cells in the EC-adherent PBMC, as well as their NK activity, increased in the presence of added IL-2. Although EC had no effect on the lysis of labeled K-562 cells by unstimulated PBMC in cold target competition experiments, they were able to compete in cytolytic assays using PBMC previously activated by exposure to IL-2 for 1 h. EC were not lysed by these briefly activated PBMC in 3-h cytotoxicity assays but were lysed by these effectors in 18-h assays and in 3-h assays using PBMC pre-activated by more prolonged culture with IL-2. The ability of IL-2 to induce NK cell adhesion to EC was not blocked by a mixture of neutralizing antisera raised against rTNF-alpha, rIL-1 alpha, and rIL-1 beta, factors known to promote leukocyte adhesion to EC. We conclude that IL-2 rapidly induces NK cell adhesion to EC and propose that this effect accounts for the disappearance of circulating NK cells after the infusion of high doses of IL-2. In addition, these results suggest that NK cells activated by IL-2 in vivo may injure the endothelium and contribute to the extravasation of plasma and the retention of fluid characteristic of IL-2 treatment.

Binding, Competitive↗

Toxicity of immunotherapy with interleukin-2 and lymphokine-activated killer cells.

Immunotherapy with IL-2 represents a major breakthrough in the management of renal cell carcinoma and malignant melanoma. At present, the toxicity of most IL-2 regimens is severe and prohibitive for clinicians not intimately familiar with the myriad of side effects associated with its use. The elucidation of the mechanism by which the lymphokine induces tumor regression, the vascular leak syndrome and other side effects will permit IL-2 to be used more safely and effectively.

Biological Factors↗

Malignant granular lymphoproliferation after Epstein-Barr virus infection: partial immunologic reconstitution with interleukin-2.

This report describes a patient who developed a malignant proliferation of granular lymphocytes following Epstein-Barr virus (EBV) infection. For many months, his illness resembled prolonged infectious mononucleosis with persistent fatigue, fever, leukocytosis, and serologic evidence of recent primary EBV infection. After approximately 1 year, however, he developed progressive granular lymphocytosis and extensive lymphocytic infiltration of the bone marrow and liver. Tests for EBV DNA in pre- and postmortem tissue samples using a sensitive DNA hybridization technique were negative. Southern blot analysis of DNA prepared from blood mononuclear cells demonstrated clonal T-cell antigen receptor gene rearrangement. Despite increased numbers of circulating lymphocytes with the morphology and surface phenotype of normal donor natural killer (NK) cells, the patient's NK activity was consistently depressed in a standard in vitro assay. However, in vitro incubation with interleukin-2 (IL-2), but not with alpha- or gamma-interferon, increased the NK activity of the patient's lymphocytes. Intravenous recombinant IL-2 treatment transiently increased the patient's blood NK activity and was associated with seroconversion to EBV nuclear antigens but failed to affect the progression of his disease. Our findings indicate that clonal granular lymphocytic proliferation may develop after EBV infection and confirm the utility of DNA hybridization analysis in distinguishing monoclonal from benign immunoreactive lymphoproliferation. Furthermore, our results suggest that certain functionally inert neoplastic granular lymphocytes acquire NK activity when exposed to IL-2.

Adult↗