Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab
B cell activating factor of the TNF family (BAFF, also known as BLyS), a cytokine that regulates homeostasis of peripheral B cells, is elevated in the circulation of patients with autoimmune diseases such as systemic lupus erythematosus (SLE). BAFF is synthetized as a membrane-bound protein that can...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-11-01
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| Series: | Frontiers in Immunology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fimmu.2018.02698/full |
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| author | Christine Kowalczyk-Quintas Dehlia Chevalley Laure Willen Camilla Jandus Michele Vigolo Pascal Schneider |
| author_facet | Christine Kowalczyk-Quintas Dehlia Chevalley Laure Willen Camilla Jandus Michele Vigolo Pascal Schneider |
| author_sort | Christine Kowalczyk-Quintas |
| collection | DOAJ |
| description | B cell activating factor of the TNF family (BAFF, also known as BLyS), a cytokine that regulates homeostasis of peripheral B cells, is elevated in the circulation of patients with autoimmune diseases such as systemic lupus erythematosus (SLE). BAFF is synthetized as a membrane-bound protein that can be processed to a soluble form after cleavage at a furin consensus sequence, a site that in principle can be recognized by any of the several proteases of the pro-protein convertase family. Belimumab is a human antibody approved for the treatment of SLE, often cited as specific for the soluble form of BAFF. Here we show in different experimental systems, including in a monocytic cell line (U937) that naturally expresses BAFF, that belimumab binds to membrane-bound BAFF with similar EC50 as the positive control atacicept, which is a decoy receptor for both BAFF and the related cytokine APRIL (a proliferation inducing ligand). In U937 cells, binding of both reagents was only detectable in furin-deficient U937 cells, showing that furin is the main BAFF processing protease in these cells. In CHO cells expressing membrane-bound BAFF lacking the stalk region, belimumab inhibited the activity of membrane-bound BAFF less efficiently than atacicept, while in furin-deficient U937 cells, belimumab inhibited membrane-bound BAFF and residual soluble BAFF as efficiently as atacicept. These reagents did not activate complement or antibody-dependent cell cytotoxicity upon binding to membrane-bound BAFF in vitro. In conclusion, our data show that belimumab can inhibit membrane-bound BAFF, and that BAFF in U937 cells is processed by furin. |
| first_indexed | 2024-04-12T04:48:06Z |
| format | Article |
| id | doaj.art-80cc5a7e5b49445989c3e9d8ea76946f |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-04-12T04:48:06Z |
| publishDate | 2018-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Immunology |
| spelling | doaj.art-80cc5a7e5b49445989c3e9d8ea76946f2022-12-22T03:47:25ZengFrontiers Media S.A.Frontiers in Immunology1664-32242018-11-01910.3389/fimmu.2018.02698392258Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody BelimumabChristine Kowalczyk-Quintas0Dehlia Chevalley1Laure Willen2Camilla Jandus3Michele Vigolo4Pascal Schneider5Department of Biochemistry, University of Lausanne, Lausanne, SwitzerlandDepartment of Biochemistry, University of Lausanne, Lausanne, SwitzerlandDepartment of Biochemistry, University of Lausanne, Lausanne, SwitzerlandDepartment of Oncology UNIL CHUV, University of Lausanne, Lausanne, SwitzerlandDepartment of Biochemistry, University of Lausanne, Lausanne, SwitzerlandDepartment of Biochemistry, University of Lausanne, Lausanne, SwitzerlandB cell activating factor of the TNF family (BAFF, also known as BLyS), a cytokine that regulates homeostasis of peripheral B cells, is elevated in the circulation of patients with autoimmune diseases such as systemic lupus erythematosus (SLE). BAFF is synthetized as a membrane-bound protein that can be processed to a soluble form after cleavage at a furin consensus sequence, a site that in principle can be recognized by any of the several proteases of the pro-protein convertase family. Belimumab is a human antibody approved for the treatment of SLE, often cited as specific for the soluble form of BAFF. Here we show in different experimental systems, including in a monocytic cell line (U937) that naturally expresses BAFF, that belimumab binds to membrane-bound BAFF with similar EC50 as the positive control atacicept, which is a decoy receptor for both BAFF and the related cytokine APRIL (a proliferation inducing ligand). In U937 cells, binding of both reagents was only detectable in furin-deficient U937 cells, showing that furin is the main BAFF processing protease in these cells. In CHO cells expressing membrane-bound BAFF lacking the stalk region, belimumab inhibited the activity of membrane-bound BAFF less efficiently than atacicept, while in furin-deficient U937 cells, belimumab inhibited membrane-bound BAFF and residual soluble BAFF as efficiently as atacicept. These reagents did not activate complement or antibody-dependent cell cytotoxicity upon binding to membrane-bound BAFF in vitro. In conclusion, our data show that belimumab can inhibit membrane-bound BAFF, and that BAFF in U937 cells is processed by furin.https://www.frontiersin.org/article/10.3389/fimmu.2018.02698/fullBAFFBLySfurinprotein sheddingcomplementantibody-dependent cell death |
| spellingShingle | Christine Kowalczyk-Quintas Dehlia Chevalley Laure Willen Camilla Jandus Michele Vigolo Pascal Schneider Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab Frontiers in Immunology BAFF BLyS furin protein shedding complement antibody-dependent cell death |
| title | Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab |
| title_full | Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab |
| title_fullStr | Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab |
| title_full_unstemmed | Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab |
| title_short | Inhibition of Membrane-Bound BAFF by the Anti-BAFF Antibody Belimumab |
| title_sort | inhibition of membrane bound baff by the anti baff antibody belimumab |
| topic | BAFF BLyS furin protein shedding complement antibody-dependent cell death |
| url | https://www.frontiersin.org/article/10.3389/fimmu.2018.02698/full |
| work_keys_str_mv | AT christinekowalczykquintas inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab AT dehliachevalley inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab AT laurewillen inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab AT camillajandus inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab AT michelevigolo inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab AT pascalschneider inhibitionofmembraneboundbaffbytheantibaffantibodybelimumab |