Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by the clonal expansion of myeloid cells, notably megakaryocytes (MKs), and an aberrant cytokine production leading to bone marrow (BM) fibrosis and insufficiency. Current treatment options are limited. TGF-β1, a profibrotic...

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Main Authors: Lecomte, S, Devreux, J, de Streel, G, van Baren, N, Havelange, V, Schröder, D, Vaherto, N, Vanhaver, C, Vanderaa, C, Dupuis, N, Pecquet, C, Coulie, PG, Constantinescu, SN, Lucas, S
Format: Journal article
Language:English
Published: American Society of Hematology 2023
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author Lecomte, S
Devreux, J
de Streel, G
van Baren, N
Havelange, V
Schröder, D
Vaherto, N
Vanhaver, C
Vanderaa, C
Dupuis, N
Pecquet, C
Coulie, PG
Constantinescu, SN
Lucas, S
author_facet Lecomte, S
Devreux, J
de Streel, G
van Baren, N
Havelange, V
Schröder, D
Vaherto, N
Vanhaver, C
Vanderaa, C
Dupuis, N
Pecquet, C
Coulie, PG
Constantinescu, SN
Lucas, S
author_sort Lecomte, S
collection OXFORD
description Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by the clonal expansion of myeloid cells, notably megakaryocytes (MKs), and an aberrant cytokine production leading to bone marrow (BM) fibrosis and insufficiency. Current treatment options are limited. TGF-β1, a profibrotic and immunosuppressive cytokine, is involved in PMF pathogenesis. While all cell types secrete inactive, latent TGF-β1, only a few activate the cytokine via cell type-specific mechanisms. The cellular source of the active TGF-β1 implicated in PMF is not known. Transmembrane protein GARP binds and activates latent TGF-β1 on the surface of regulatory T lymphocytes (Tregs) and MKs or platelets. Here, we found an increased expression of GARP in the BM and spleen of mice with PMF and tested the therapeutic potential of a monoclonal antibody (mAb) that blocks TGF-β1 activation by GARP-expressing cells. GARP:TGF-β1 blockade reduced not only fibrosis but also the clonal expansion of transformed cells. Using mice carrying a genetic deletion of Garp in either Tregs or MKs, we found that the therapeutic effects of GARP:TGF-β1 blockade in PMF imply targeting GARP on Tregs. These therapeutic effects, accompanied by increased IFN-γ signals in the spleen, were lost upon CD8 T-cell depletion. Our results suggest that the selective blockade of TGF-β1 activation by GARP-expressing Tregs increases a CD8 T-cell-mediated immune reaction that limits transformed cell expansion, providing a novel approach that could be tested to treat patients with myeloproliferative neoplasms.
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spelling oxford-uuid:0a271b74-1fb0-4e66-a032-6ce54f1911b92023-06-12T18:09:11ZTherapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosisJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0a271b74-1fb0-4e66-a032-6ce54f1911b9EnglishSymplectic ElementsAmerican Society of Hematology2023Lecomte, SDevreux, Jde Streel, Gvan Baren, NHavelange, VSchröder, DVaherto, NVanhaver, CVanderaa, CDupuis, NPecquet, CCoulie, PGConstantinescu, SNLucas, SPrimary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by the clonal expansion of myeloid cells, notably megakaryocytes (MKs), and an aberrant cytokine production leading to bone marrow (BM) fibrosis and insufficiency. Current treatment options are limited. TGF-β1, a profibrotic and immunosuppressive cytokine, is involved in PMF pathogenesis. While all cell types secrete inactive, latent TGF-β1, only a few activate the cytokine via cell type-specific mechanisms. The cellular source of the active TGF-β1 implicated in PMF is not known. Transmembrane protein GARP binds and activates latent TGF-β1 on the surface of regulatory T lymphocytes (Tregs) and MKs or platelets. Here, we found an increased expression of GARP in the BM and spleen of mice with PMF and tested the therapeutic potential of a monoclonal antibody (mAb) that blocks TGF-β1 activation by GARP-expressing cells. GARP:TGF-β1 blockade reduced not only fibrosis but also the clonal expansion of transformed cells. Using mice carrying a genetic deletion of Garp in either Tregs or MKs, we found that the therapeutic effects of GARP:TGF-β1 blockade in PMF imply targeting GARP on Tregs. These therapeutic effects, accompanied by increased IFN-γ signals in the spleen, were lost upon CD8 T-cell depletion. Our results suggest that the selective blockade of TGF-β1 activation by GARP-expressing Tregs increases a CD8 T-cell-mediated immune reaction that limits transformed cell expansion, providing a novel approach that could be tested to treat patients with myeloproliferative neoplasms.
spellingShingle Lecomte, S
Devreux, J
de Streel, G
van Baren, N
Havelange, V
Schröder, D
Vaherto, N
Vanhaver, C
Vanderaa, C
Dupuis, N
Pecquet, C
Coulie, PG
Constantinescu, SN
Lucas, S
Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title_full Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title_fullStr Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title_full_unstemmed Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title_short Therapeutic activity of GARP:TGF-β1 blockade in murine primary myelofibrosis
title_sort therapeutic activity of garp tgf β1 blockade in murine primary myelofibrosis
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