Endothelial cell functions impaired by interferon in vitro: Insights into the molecular mechanism of thrombotic microangiopathy associated with interferon therapy.

Introduction: Interferon (IFN)-α and IFN-β approved for treatment of chronic hepatitis C viral infection and multiple sclerosis respectively have been linked to thrombotic microangiopathy (TMA) affecting renal function. Since the molecular mechanisms underlying this severe complication remain largely unclear, we aimed to investigate whether IFN affects directly in vitro endothelial cell functions associated with angiogenesis and blood haemostasis, as well as endothelial cell-derived vasodilators of nitric oxide (NO) and prostacyclin.

Methods: Proliferation and survival of human umbilical vein endothelial cells (HUVECs) were measured by BrdU incorporation and alamarBlue assays.

Establishment of the first WHO International Standard for etanercept, a TNF receptor II Fc fusion protein: Report of an international collaborative study.

Etanercept, a recombinant human tumor necrosis factor (TNF) receptor Fc fusion protein is an effective treatment option in adults with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis or plaque psoriasis and paediatrics with juvenile idiotypic arthritis and plaque psoriasis. Patent expiration in Europe and intense development of various etanercept products worldwide triggered a need for an international reference standard to facilitate determination of biological activity. Therefore, three candidate preparations of etanercept were lyophilized and evaluated in a multi-centre collaborative study comprising twenty eight laboratories from 15 countries for their suitability to serve as an international standard for the bioactivity of TNF receptor II Fc fusion proteins (international nonproprietary name, Etanercept).

IL-27 Promotes Proliferation of Human Leukemic Cell Lines Through the MAPK/ERK Signaling Pathway and Suppresses Sensitivity to Chemotherapeutic Drugs.

IL-27 is a pleiotropic cytokine of the IL-6/IL-12 family with diverse biological functions. Previous in vivo studies have suggested the antitumor activities of IL-27 in animal models, whereas clinical observations indicate the link of IL-27 in tumor progression. IL-27 has recently been shown to cause inhibition of proliferation on primary leukemic cells from pediatric patients, but information on its role in human leukemic cell lines is limited.

Standardization of human IL-29 (IFN-λ1): establishment of a World Health Organization international reference reagent for IL-29 (IFN-λ1).

Human interleukin-29 (IL-29), a helical cytokine with interferon-like activities, is currently being developed as a clinical biotherapeutic to treat chronic hepatitis C infection and some cancers. As such, the World Health Organization (WHO) has recognized a need for biological standardization of IL-29 and the establishment of an internationally available reference reagent of IL-29. In order to accomplish this, an international collaborative study that evaluates WHO candidate reference reagents of IL-29 was instigated by the National Institute for Biological Standards and Control (NIBSC) in 2010 and was carried out in the succeeding year.

The 2nd International Standard for Interleukin-2 (IL-2). Report of a collaborative study.

Two candidate preparations of human sequence recombinant Interleukin-2 (IL-2) were formulated and lyophilized at NIBSC prior to evaluation in a collaborative study for their suitability to serve as a replacement international standard. The preparations were tested by eight laboratories using in vitro bioassays and immunoassays. The candidate preparation 86/500 was judged suitable to serve as a replacement international standard based on the data obtained for activity and stability.

Use of a standardized MxA protein measurement-based assay for validation of assays for the assessment of neutralizing antibodies against interferon-β.

Effective monitoring of the development of neutralizing antibodies (NAbs) against IFN-β in multiple sclerosis (MS) patients on IFN-β therapy is important for clinical decision making and disease management. To date, antiviral assays have been the favored approach for NAb determination, but variations in assay conditions between laboratories and the increasing use of novel assays have contributed to the reporting of inconsistent antibody data between laboratories and between products. This study, undertaken at the request of the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA), is a joint effort by manufacturers of IFN-β products (approved in Europe) towards harmonization of a NAb assay that facilitates generation of comparable NAb data, which, in conjunction with clinical outcomes, should prove useful for clinicians treating MS patients with IFN-β products.

Severity of the TGN1412 trial disaster cytokine storm correlated with IL-2 release.

Aim: To determine if cytokine release with a solid phase assay is predictive of adverse responses for a range of therapeutic mAbs.

Methods: Cytokine ELISAs and a multi-array system were used to compare responses generated by different therapeutic mAbs using a solid phase assay. Flow cytometry was employed to determine the cellular source of those cytokines.

The 1st International standard for transforming growth factor-β3 (TGF-β3).

One candidate preparation of human sequence recombinant transforming growth factor-β3 (TGF-β3) was formulated and lyophilized at NIBSC prior to evaluation in a collaborative study for its suitability to serve as an international standard. The preparation was tested by 8 laboratories using in vitro bioassays and immunoassays. The candidate preparation 09/234 was judged suitable to serve as an international standard based on the data obtained for biological activity and stability.

Treatment of colitis with a commensal gut bacterium engineered to secrete human TGF-β1 under the control of dietary xylan 1.

Background: While cytokine therapy and the use of immunosuppressive cytokines such as transforming growth factor-β (TGF-β) offer great potential for the treatment of inflammatory bowel disease (IBD), issues concerning formulation, stability in vivo, delivery to target tissues, and potential toxicity need to be addressed. In consideration of these problems we engineered the human commensal bacterium Bacteroides ovatus for the controlled in situ delivery of TGF-β(1) and treatment of colitis.

Methods: Sequence encoding the human tgf-β1 gene was cloned downstream of the xylanase promoter in the xylan operon of B.

An assessment of biological potency and molecular characteristics of different innovator and noninnovator interferon-beta products.

Approved innovator products and their noninnovator "copy" versions are likely to vary in their quality, eg, physicochemical characteristics and biological activity, with important implications for clinical efficacy and safety. Therefore, it is important to study and thoroughly evaluate the noninnovator products in comparison with approved products at the preclinical and clinical stages. We have obtained 4 noninnovator interferon (IFN)-β-1a products currently marketed in Latin America and Iran and compared these with approved IFN-β-1a products (Avonex and Rebif) obtained from the same geographical regions with respect to biological potency, estimated by in vitro bioassays, and molecular characteristics, assessed by immunoblotting and high-performance liquid chromatography.

"Cytokine storm" in the phase I trial of monoclonal antibody TGN1412: better understanding the causes to improve preclinical testing of immunotherapeutics.

The CD28-specific mAb TGN1412 rapidly caused a life-threatening "cytokine storm" in all six healthy volunteers in the Phase I clinical trial of this superagonist, signaling a failure of preclinical safety testing. We report novel in vitro procedures in which TGN1412, immobilized in various ways, is presented to human white blood cells in a manner that stimulates the striking release of cytokines and profound lymphocyte proliferation that occurred in vivo in humans. The novel procedures would have predicted the toxicity of this superagonist and are now being applied to emerging immunotherapeutics and to other therapeutics that have the potential to act upon the immune system.

Biological activity of interleukins-28 and -29: comparison with type I interferons.

Despite binding to receptors distinct from those of type I interferons (IFNs), human interleukins-28A, -28B and -29 (IL-28A, IL-28B and IL-29; alternatively named IFN lambda-2 {IFN-lambda2}, IFN-lambda3 and IFN-lambda1, respectively, or collectively, type III IFNs), a small family of three structurally-related cytokines, are, like IFNs, known to induce antiviral activity. To further biologically characterize IL-28A and IL-29, we compared their activities with those of IFNs in a range of human cell lines. We found that they induced antiviral activity in fewer cell lines and more weakly than IFNs; also IL-28A was less active than IL-29.