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Propionibacterium acnes ‐induced hepatic granuloma formation is impaired in mice lacking tetraspanin CD9
Author(s) -
Yamane Hiroyuki,
Tachibana Isao,
Takeda Yoshito,
Saito Yoshiyuki,
Tamura Yoshio,
He Ping,
Suzuki Mayumi,
Shima Yoshihito,
Yoneda Tsutomu,
Hoshino Shigenori,
Inoue Koji,
Kijima Takashi,
Yoshida Mitsuhiro,
Kumagai Toru,
Osaki Tadashi,
Eishi Yoshinobu,
Kawase Ichiro
Publication year - 2005
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1793
Subject(s) - propionibacterium acnes , granuloma , tetraspanin , immunostaining , pathology , inflammation , biology , immunology , chemistry , cell , immunohistochemistry , medicine , genetics , bacteria
The granuloma is a host defence response to persistent pathogenic irritants. In the process of granuloma formation, the activation, migration, and fusion of macrophages occur locally, but the mechanisms involved remain elusive. Tetraspanins regulate cell migration and fusion by organizing functional molecular complexes in membrane microdomains. Here we investigated the role of tetraspanin CD9 in hepatic granuloma formation. Immunostaining of the liver of untreated wild‐type mice showed that CD9 was expressed by vascular endothelial cells and perivenular hepatocytes. When intrahepatic granulomas were induced by intravenous injection of Propionibacterium acnes , hepatocyte CD9 was extensively upregulated, while inflammatory cells constituting granulomas were mostly negative for CD9. Compared with wild‐type littermates, CD9‐knockout mice showed dissemination of Propionibacterium acnes and reduced number and size of granulomas after the injection. Moreover, production of granuloma‐inducing cytokines, TNF‐α and IFN‐γ, was delayed and chemotactic activity for macrophages was suppressed in the liver of mutant mice. These results suggest that CD9 is one of the proteins that promotes granuloma formation in the liver. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.