Polyarthrite rhumatoïde | EPFL Graph Search

La polyarthrite rhumatoïde (PR) est une maladie dégénérative inflammatoire chronique, caractérisée par une atteinte articulaire souvent bilatérale et symétrique, évoluant par poussées vers la déformation et la destruction des articulations atteintes. Le diagnostic peut en être malaisé en début d'évolution, faute de signe clinique spécifique et de constance des signes biologiques et à cause du retard d'apparition des érosions articulaires radiologiques ou de leur lente évolution. La polyarthrite rhumatoïde est une maladie auto-immune qui semble avoir des origines parfois génétiques et parfois environnementales (ou les deux). Synonymes

Polyarthrite chronique évolutive (PCE) (F. Costes et J. Forestier, 1929), polyarthrite rhumatismale, arthrite rhumatoïde, arthrodynie (Cullen), goutte asthénique primitive (Landré-Beauvais), polyarthrite chronique déformante ou p. c. inflammatoire ou p. c. rhumatismale (De Sèze et Ryckewaert) ou p. c. symétrique progressive (Bezançon et M

Introducing tolerance to foreign and partly foreign proteins by erythrocyte binding and artificial glycosylations

Kym Lorenz Brünggel

Over the last few years, protein drugs have steadily gained importance in the clinic. Compared to small molecule drugs, protein drugs are taken up by antigen presenting cells, which degrade the proteins into peptides that are then presented on major histocompatability complex I and II to CD8+ respectively CD4+ T-cells. CD4+ T-cells are then able to activate B-cells, which upon activation will produce anti-drug antibodies. While anti-drug antibodies have mostly been viewed as a safety risk leading to drug injection related side effects, they have recently been proven to diminish the efficacy of the treatment. High antibody titers against Humira, a clinically approved monoclonal antibody used to treat rheumatoid arthritis, have been associated with low serum drug concentration and high disease activity score, ultimately leading to treatment failure. Two approaches to induce tolerance were developed in the Hubbell lab. One approach utilizes protein variants that are designed to bind to circulating erythrocytes. As 1 % of erythrocytes undergo apoptosis each day and are taken up by antigen presenting cells, along with the bound protein, they are presented to the immune system in a non-inflammatory tolerogenic fashion. Immunological tolerance is thereby induced against the apoptotic erythrocyte debris and the associated bound protein. The second approach uses synthetic glucose, galactose or mannose polymers conjugated to the target protein. The polymers target C-type lectins, which are known to clear apoptotic debris, leading to presentation of the protein by hepatic antigen presenting cells in a tolerogenic liver microenvironment. This thesis investigates the potential of these approaches to induce tolerance towards protein drugs. Arylsulfatase B was used as a model protein to investigate the potential of tolerance induction by targeting circulating erythrocytes, as 97% of patients receiving arylsulfatase B develop anti-drug antibodies. An erythrocyte binding variant of arylsufatase B was created by chemically conjugating the erythrocyte binding peptide ERY1 to arylsulfatse B. In mice receiving two doses of ERY1-arylsulfatase B one week apart followed by weekly doses of arylsulfatase B a significant delay of four week in the production of anti-drug Antibodies was found when compared to mice receiving weekly doses of only arylsulfatase B. To investigate the ability of synthetic glyco-polymers to induce tolerance towards protein drugs we used asparaginase as model protein. Between 37.5 % to 75% of patients treated with asparaginase develop anti-drug antibodies. Administering three intravenous injections of asparaginase-conjugated to glucose polymers before eight weeks of treatment with asparaginase significantly reduced anti-drug antibody titers by a factor of 125 when compared to animals only receiving eight weeks of treatment with asparaginase. Three pre-injections with asparaginase conjugated to the galactose or mannose polymer led to a reduction in anti-drug antibody titers by a factor of 12 respectively 400 after 5 weeks of treatment with asparaginase when compared to mice receiving only asparaginase for 5 weeks. These results indicates that synthetic glyco polymers, especially mannose and glucose based ones, are able to induce long term tolerance towards asparaginase. Synthetic glucose and mannose polymers therefore represent an excellent molecular approach to induce tolerance towards protein drugs.

EPFL2018

Thrombin-sensitive photodynamic agents: A novel strategy for selective synovectomy in rheumatoid arthritis

Hubert van den Bergh

Protease-sensitive macromolecular prodrugs have attracted interest for bio-responsive drug delivery to sites with up-regulated proteolytic activities such as inflammatory or cancerous lesions. Here we report the development of a novel polymeric photosensitizer prodrug (T-PS) to target thrombin, a protease up-regulated in synovial tissues of rheumatoid arthritis (RA) patients, for minimally invasive photodynamic synovectomy. In T-PS, multiple photosensitizer units are tethered to a polymeric backbone via short, thrombin-cleavable peptide linkers. Photoactivity of the prodrug is efficiently impaired due to energy transfer between neighbouring photosensitizer units. T-PS activation by exogenous and endogenous thrombin induced an increase in fluorescence emission by a factor of 16 after in vitro digestion and a selective fluorescence enhancement in arthritic lesions in vivo, in a collagen-induced arthritis mouse model. In vitro studies on primary human synoviocytes showed a phototoxic effect only after enzymatic digestion of the prodrug and light irradiation, thus demonstrating the functionality of T-PS induced PDT. The developed photosensitizer prodrugs combine the passive targeting capacity of macromolecular drug delivery systems with site-selective photosensitizer release and activation. They illuminate lesions with pathologically enhanced proteolytic activity and induce cell death, subsequent to irradiation. (c) 2009 Elsevier B.V. All rights reserved.

2009

Introducing tolerance to foreign and partly foreign proteins by erythrocyte binding and artificial glycosylations

Kym Lorenz Brünggel

EPFL2018