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Megakaryocytes compensate for Kit insufficiency in murine arthritis
The growth factor receptor Kit is involved in hematopoietic and nonhematopoietic development. Mice bearing Kit defects lack mast cells; however, strains bearing different Kit alleles exhibit diverse phenotypes. Herein, we investigated factors underlying differential sensitivity to IgG-mediated arthr...
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Published in: | The Journal of clinical investigation 2017-05, Vol.127 (5), p.1714 |
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Main Authors: | , , , , , , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Online Access: | Get full text |
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Summary: | The growth factor receptor Kit is involved in hematopoietic and nonhematopoietic development. Mice bearing Kit defects lack mast cells; however, strains bearing different Kit alleles exhibit diverse phenotypes. Herein, we investigated factors underlying differential sensitivity to IgG-mediated arthritis in 2 mast cell-deficient murine lines: [Kit.sup.Wsh/Wsh], which develops robust arthritis, and [Kit.sup.W/Wv], which does not. Reciprocal bone marrow transplantation between [Kit.sup.W/Wv] and [Kit.sup.Wsh/Wsh] mice revealed that arthritis resistance reflects a hematopoietic defect in addition to mast cell deficiency. In [Kit.sup.W/Wv] mice, restoration of susceptibility to IgG-mediated arthritis was neutrophil independent but required IL-1 and the platelet/ megakaryocyte markers NF-E2 and glycoprotein VI. In [Kit.sup.W/Wv] mice, platelets were present in numbers similar to those in WT animals and functionally intact, and transfer of WT platelets did not restore arthritis susceptibility. These data implicated a platelet-independent role for the megakaryocyte, a Kit-dependent lineage that is selectively deficient in [Kit.sup.W/Wv] mice. Megakaryocytes secreted IL-1 directly and as a component of circulating microparticles, which activated synovial fibroblasts in an IL-1-dependent manner. Transfer of WT but not IL-1-deficient megakaryocytes restored arthritis susceptibility to [Kit.sup.W/Wv] mice. These findings identify functional redundancy among Kit-dependent hematopoietic lineages and establish an unanticipated capacity of megakaryocytes to mediate IL-1-driven systemic inflammatory disease. |
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ISSN: | 0021-9738 1558-8238 |
DOI: | 10.1172/JCI84598. |