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IL‐4 promotes the formation of multinucleated giant cells from macrophage precursors by a STAT6‐dependent, homotypic mechanism: contribution of E‐cadherin
Author(s) -
Moreno Jose L.,
Mikhailenko Irina,
Tondravi Mehrdad M.,
Keegan Achsah D.
Publication year - 2007
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0107058
Subject(s) - microbiology and biotechnology , cadherin , biology , giant cell , multinucleate , stat6 , macrophage , foreign body giant cell , in vitro , interleukin 4 , cell , immunology , cytokine , biochemistry , medicine , genetics , pathology
Multinucleated giant cells (MNG) are central players in the inflammatory response to foreign materials and in adverse responses to implants. IL‐4 promotes the formation of MNG from bone marrow‐derived precursors in vitro and participates in the development of the foreign body reaction in vivo. Therefore, we investigated the mechanism by which IL‐4 promotes formation of MNG and engulfment of foreign bodies. We found that generation of MNG cells by IL‐4 was dependent on cell density and expression of STAT6; macrophages derived from STAT6 −/− mice were unable to form MNG in response to IL‐4. No soluble factors including CCL2 or supernatants from IL‐4‐treated macrophages compensated for the lack of MNG cells in STAT6 −/− cultures. We found that IL‐4 must remain present during the full differentiation process and that STAT6 +/+ macrophage precursors retained their ability to differentiate into MNG over time. These MNG were able to internalize large particles efficiently, and the mononuclear STAT6 −/− macrophages were unable to do so. Furthermore, we found that IL‐4 induced expression of E‐cadherin and dendritic cell‐specific transmembrane protein in a STAT6‐dependent manner. E‐cadherin expression was critical for the formation of MNG cells by IL‐4; an anti‐E‐cadherin antibody prevented the formation of large MNG. In addition, we found that STAT6 −/− progenitors failed to fuse with STAT6 +/+ , revealing the need for a homotypic interaction. Thus, IL‐4 promotes the formation of MNG in a STAT6‐dependent manner by regulating cell surface expression of E‐cadherin, leading to homotypic cell fusion and the incorporation of large foreign bodies.