In Vivo Studies with Chimeric Toxins Interleukin-2 Fusion Toxins as Immunosuppressive Agents

AbstractThe use of recombinant interleukin-2 (IL-2) as a therapeutic protein has been limited by significant toxicities despite its demonstrated ability to induce durable tumor-regression in cancer patients. The adverse events and limited efficacy of IL-2 treatment are due to the preferential binding of IL-2 to cells that express the high-affinity, trimeric receptor, IL-2Rαβγ such as endothelial cells and T-regulatory cells, respectively. Here, we describe a novel bispecific heavy-chain only antibody which binds to and activates signaling through the heterodimeric IL-2Rβγ receptor complex that is expressed on resting T-cells and NK cells. By avoiding binding to IL-2Rα, this molecule circumvents the preferential T-reg activation of native IL-2, while maintaining the robust stimulatory effects on T-cells and NK-cells in vitro. In vivo studies in both mice and cynomolgus monkeys confirm the molecule’s in vivo biological activity, extended pharmacodynamics due to the Fc portion of the molecule, and enhanced safety profile. Together, these results demonstrate that the bispecific antibody is a safe and effective IL-2R agonist that harnesses the benefits of the IL-2 signaling pathway as a potential anti-cancer therapy.

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Statins as novel immunomodulators: From cell to potential clinical benefit

Thrombosis and Haemostasis ◽

10.1160/th03-04-0249 ◽

2003 ◽

Vol 90 (10) ◽

pp. 607-610 ◽

Cited By ~ 18

Author(s):

François Mach

Keyword(s):

Immune Response ◽

International Workshop ◽

Immunosuppressive Agents ◽

Medical Science ◽

In Vivo Studies ◽

Organ Rejection ◽

Mhc Ii ◽

Potential Clinical Benefit ◽

Ifn Γ

SummaryIn the last decades, substantial progress has been made in understanding the relationship between lipid disorders and prevention of cardiac ischemic disease. Statins competitively inhibit 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase, an enzyme crucial to cholesterol biosynthesis. Statins have long been thought to exert their benefits by reducing cholesterol synthesis, but the fact that mevalonate is the precursor of isoprenoids that regulate diverse cellular functions has led investigators to examine pleiotropic effects for these agents. Statins have never been shown to be involved in the immune response, although two clinical trials have suggested that in heart transplant patients, statin therapy has beneficial effects on the incidence of cardiac rejection, coronary vasculopathy, and survival.Major Histocompatibility Complex class II (MHC-II) molecules, which affect the immune response and organ rejection after transplantation, may be induced by the pro-inflammatory cyto-kine interferon gamma (IFN-γ). Recently, it has been demonstrated that statins repress the induction of MHC-II by IFN-γ in vitro, and thus may suggest a potential role for statins as immunosuppressive agents in vivo. Indeed, two recent in vivo studies performed on different animal models provide further evidence that statin-treatment positively influence immunological disorders.This publication was partially financed by Serono Foundation for the Advancement of Medical Science.Part of this paper was originally presented at the 2nd International Workshop on New Therapeutic Targets in Vascular Biology from February 6-9, 2003 in Geneva, Switzerland.

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Reduction in Factor VIII Inhibitors Mediated through Tolerogenic Antigen Presentation by immature Dendritic Cells.

Blood ◽

10.1182/blood.v108.11.762.762 ◽

2006 ◽

Vol 108 (11) ◽

pp. 762-762

Author(s):

Mohammad Qadura ◽

Andrea Labelle ◽

Kirsten Walker ◽

Kathleen Pratt ◽

Maha Othman ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Dendritic Cells ◽

Factor Viii ◽

Immunosuppressive Agents ◽

In Vivo Studies ◽

C2 Domain ◽

In Vitro Proliferation ◽

Immature Dendritic Cells

Abstract Inhibitory antibodies are a major complication of factor VIII (FVIII) treatment in patients with hemophilia A. Hemophilic patients with inhibitors face major challenges in terms of their bleeding treatments and the cost of these therapies. The use of tolerogenic immunotherapy prior to protein replacement therapy represents a novel strategy to prevent the initiation of an immune response directed against FVIII. Dendritic cells (DCs) are professional antigen presenting cells (APCs) that play a central role in initiating and directing T−cells towards either immunity or tolerance. We isolated myeloid immature dendritic cells (iDCs) from murine bone marrow and pulsed the cells with FVIII protein or the C2 domain of FVIII (FVIII−iDCs/C2−iDCs) under a non−inflammatory environment and in the presence or absence of anti−inflammatory and immunosuppressive agents such as dexamethasone (Dex) and andrographolide (Andro). One million pulsed−iDCs were infused into a group of five hemophilic Balb/c mice on a weekly basis for three weeks through tail vein injection (iv). Anti−FVIII antibody levels were monitored by functional Bethesda assay after a subsequent challenge with four weekly IV FVIII (2 IU/ml) or C2 (125 ng) injections. Flow cytometry assessment of DC maturation markers indicated that the DCs retained their immature state after pulsing with FVIII or the C2 domain in the presence of Andro or Dex. In vitro proliferation and cytokine release studies using naïve hemophilic mouse CD−4+ T cells and FVIII−iDCs or C2−iDCs in the presence/absence of Dex or Andro showed that the pulsed−iDCs are tolerogenic and result in a marked reduction in the secretion of inflammatory cytokines. We then studied the tolerogenic potential of FVIII−iDCs and C2−iDCs in vivo. We infused pulsed−iDCs that were cultured in the presence or absence of Dex/Andro into naïve hemophilic mice. We observed a 20% and 70% reduction in the levels of FVIII inhibitors in mice that received FVIII−iDCs or C2−iDCs respectively after FVIII or C2 challenges in comparison to control mice that only received FVIII or C2 challenges. Mice that received FVIII−iDCs were re−challenged with 2 IU of FVIII 10 weeks after the last of the four consecutive FVIII challenges. Our results indicate that these mice still showed a 25% reduction in the levels of FVIII inhibitors after the re−challenge suggesting that iDCs were able to induce a tolerogenic memory response against FVIII. The in vivo studies for FVIII pulsed iDCs in the presence of Andro are still in progress. In aggregate, these studies indicate that the administration of immature DCs pulsed with FVIII or the C2 domain of FVIII can significantly reduce the immune response to FVIII following subsequent IV challenges. However, this immunotherapeutic strategy does not completely abolish the anti−FVIII response, suggesting that additional supplementary approaches will be necessary to prevent the development of this treatment−related complication.

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Interleukin-2 and Lanreotide in the Treatment of Medullary Thyroid Cancer: In Vitro and In Vivo Studies

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2013-1443 ◽

2013 ◽

Vol 98 (10) ◽

pp. E1567-E1574 ◽

Cited By ~ 10

Author(s):

Giovanni Vitale ◽

Giovanni Lupoli ◽

Rosario Guarrasi ◽

Annamaria Colao ◽

Alessandra Dicitore ◽

...

Keyword(s):

Thyroid Cancer ◽

Medullary Thyroid Cancer ◽

Interleukin 2 ◽

In Vivo Studies ◽

Medullary Thyroid

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Metabolism of Tac (IL2Ralpha): physiology of cell surface shedding and renal catabolism, and suppression of catabolism by antibody binding.

Journal of Experimental Medicine ◽

10.1084/jem.183.4.1587 ◽

1996 ◽

Vol 183 (4) ◽

pp. 1587-1602 ◽

Cited By ~ 49

Author(s):

R P Junghans ◽

T A Waldmann

Keyword(s):

T Cells ◽

T Cell Activation ◽

Cell Activation ◽

Interleukin 2 ◽

The Body ◽

In Vivo Studies ◽

Soluble Form ◽

Soluble Receptor ◽

The Impact

The interleukin 2 receptor alpha (IL2Ralpha; CD25; Tac) is the prototypic model for soluble receptor studies. It exists in vivo as a transmembrane complete molecule (TM-Tac) on cell surfaces and as a truncated soluble form (sTac; sIL2R alpha). sTac has been used as a serum marker of T cell activation in immune disorders and of tumor burden in Tac-expressing malignancies. In vivo, serum levels of all soluble proteins depend on the balance between production and catabolism, but little is known about the metabolic features of this class of molecules. We have developed a model for Tac metabolism that incorporates new insights in its production and catabolism. Tac was shed from the surface of malignant and activated human T cells with a model half-life (t1/2) of 2-6h, but which was prolonged under certain circumstances. The rate of shedding is first order overall and nonsaturable over a two order of magnitude range of substrate (TM-Tac) expression. Once shed from cells Tac is subject to catabolic activities in the host. In vivo studies in mice showed that 90% of Tac was catabolized by the kidney with a t1/2 of 1 h and a filtration fraction of 0.11 relative to creatinine. The remaining 10% of catabolism was mediated by other tissues with a t1/2 of 10 h. Approximately 1-3% of sTac is excreted intact as proteinuria with the remaining 97-99% catabolized to amino acids. Antibody to the receptor induced a marked delay in sTac catabolism by preventing filtration of the smaller protein through the renal glomerulus and additionally suppressing other nonrenal catabolic mechanisms. A discrepancy between the catabolic rats for Tac and anti-Tac in the same complex was interpreted as a previously unrecognized differential catabolic mechanism, suggesting features of the Brambell hypothesis and immunoglobulin G transport and catabolism, in which the antigen-in-complex in intracellular vesicles is relatively less protected from catabolism than the associated antibody. In light of the pivotal role played by the kidney in sTac catabolism and the impact of administered antibody, the serum concentration of Tac in the settings of renal dysfunction or antibody therapy is not a suitable surrogate of activated T cells or of the body burden of tumor. These results provide parameters for assessing soluble receptor-ligand interactions generally.

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Pulmonary Immunity to Viral Infection: Adenovirus Infection of Lung Dendritic Cells Renders T Cells Nonresponsive to Interleukin-2

Journal of Virology ◽

10.1128/jvi.80.4.1826-1836.2006 ◽

2006 ◽

Vol 80 (4) ◽

pp. 1826-1836 ◽

Cited By ~ 14

Author(s):

Allison T. Thiele ◽

Tina L. Sumpter ◽

Joanna A. Walker ◽

Qi Xu ◽

Cheong-Hee Chang ◽

...

Keyword(s):

Cell Proliferation ◽

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Interleukin 2 ◽

In Vivo Studies ◽

T Cell Proliferation ◽

Interleukin 12

ABSTRACT Adenovirus (Ad) infection has been identified as predisposing hosts to the development of pulmonary disease through unknown mechanisms. Lung dendritic cells (DCs) are vital for initiating pulmonary immune responses; however, the effects of Ad infection on primary lung DC have not been studied. In contrast to the effects on bone marrow- and monocyte-derived DCs, the current study shows that Ad infection of murine BALB/c lung DCs in vitro and in vivo suppresses DC-induced T-cell proliferation. The effect of Ad on DCs was not due to a downregulation of major histocompatibility complex or costimulatory molecules. Analysis of the production of interleukin-12 (IL-12), alpha interferon (IFN-α), and IFN-γ by the Ad-infected DCs shows no significant differences over noninfected control lung DCs. Ad-induced suppression was not due to a deficiency of IL-2 or other DC-secreted factors and was dependent on viral protein synthesis, as UV irradiation of Ad abrogated the suppressive effect. Results suggest that Ad-infected DCs induce T cells to be nonresponsive to IL-2 during primary coculture, as the addition of IL-2 in secondary cultures recovered T-cell proliferation. In vivo studies supported in vitro results showing that Ad infection resulted in lung T cells with decreased proliferative ability. This study demonstrates that Ad infection induces local immunoincompetence by altering DC-T-cell interactions.

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Supplementation of Bovine Colostrum in Inflammatory Bowel Disease: Benefits and Contraindications

Advances in Nutrition ◽

10.1093/advances/nmaa120 ◽

2020 ◽

Author(s):

Michał Sienkiewicz ◽

Patrycja Szymańska ◽

Jakub Fichna

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Intestinal Inflammation ◽

Immunosuppressive Agents ◽

Bovine Colostrum ◽

In Vivo Studies ◽

Inflammatory Bowel ◽

Chronic Intestinal Inflammation

ABSTRACT Inflammatory bowel disease (IBD) is a group of chronic relapsing disorders whose etiology has not been fully explained. Therefore, available therapeutic approaches for IBD patients are still insufficient. Current treatment strategies are targeted to immune system dysfunctions, often associated with alternations in the microbiota, which contribute to the development of chronic intestinal inflammation. Therapeutics include anti-inflammatory drugs such as aminosalicylates and corticosteroids, immunosuppressive agents, antibiotics, and biological agents such as infliximab and vedolizumab. Auxiliary therapies involve a balanced and personalized diet, healthy lifestyle, avoiding stress, as well as dietary supplements. In this review, we discuss the use of bovine colostrum (BC) as a therapeutic agent, including its advantages and contraindications. We summarize our knowledge on well-researched BC constituents and their effects on the gastrointestinal tract as evidenced in in vitro and in vivo studies.

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