title: Bacterial lipopolysaccharide-induced expression of the IkappaB protein MAIL in B-lymphocytes and macrophages.
abstract: Molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL), a recently cloned nuclear IkappaB protein induced by lipopolysaccharide (LPS) stimulation in lymphoid organs, is involved in the regulation of inflammatory responses. The present in situ hybridization and immunohistochemical analyses revealed the distinct expression of the MAIL mRNA and protein in B-lymphocytes of the white pulp of the spleen and cortical lymphoid follicles of lymph nodes in LPS-injected mice. MAIL signals were also localized in F4/80-positive macrophages in these organs. LPS clearly induced MAIL expression in cultured B-lymphocytes and monocytes/macrophages, but only faintly so in T-lymphocytes, fibroblasts, and endothelial cells. MAIL was also induced by inflammatory cytokines such as interleukin-1 and -6, and tumor necrosis factor in cultured cells. Northern blot, Western blot, and in situ hybridization analyses showed that the major expression product of the Mail gene was a long splicing variant (MAIL-L) rather than a short one, both in lymphoid organs and cultured cells. These results collectively indicate that LPS induces MAIL-L predominantly in B-lymphocytes and macrophages.
authors.affiliation: Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan. khiroshi@kic.kazusa.or.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Iwanaga
authors.forename: Koshi
authors.initials: K
authors.lastname: Mori
authors.forename: Katsushi
authors.initials: K
authors.lastname: Kanehira
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fujikura
authors.forename: Masami
authors.initials: M
authors.lastname: Morimatsu
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saito
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D015153:Blotting, Western; D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008221:Lymphoid Tissue / Q000166:cytology; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D008070:Lipopolysaccharides; C485947:Nfkbiz protein, mouse; D009687:Nuclear Proteins; D012333:RNA, Messenger