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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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Bibliographic Details
Published in:The Journal of clinical investigation 2017-05, Vol.127 (5), p.1714
Main Authors: Cunin, Pierre, Penke, Loka R, Thon, Jonathan N, Monach, Paul A, Jones, Tatiana, Chang, Margaret H, Chen, Mary M, Melki, Imene, Lacroix, Steve, Iwakura, Yoichiro, Ware, Jerry, Gurish, Michael F, Italiano, Joseph E, Boilard, Eric, Nigrovic, Peter A
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Language:English
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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.
ISSN:0021-9738
1558-8238
DOI:10.1172/JCI84598.