title: Maltose-binding protein isolated from Escherichia coli induces Toll-like receptor 2-mediated viability in U937 cells.
abstract: BACKGROUND
  Stimulation of Toll-like receptors (TLRs) by microbial products has been utilised to potentiate immune responses against haematologic malignancies. The maltose-binding protein (MBP) of Escherichia coli could induce the activation of immune cells via TLR4. The aim of the present study was to investigate whether TLRs mediated the biological effects of MBP on U937 and Jurkat cells in vitro. METHODS We observed the effect of MBP on U937 and Jurkat cells by using the WST, cell cycle analysis and morphological observation. Further, cells were stimulated with MBP for indicated times and doses, and detected by RT-PCR, western blotting, immunohistochemistry and immunofluorescence staining to investigate the mechanisms involved in cell viability.
  
  
  RESULTS
  MBP enhanced the viability of U937 and Jurkat cells, and the effects were blocked by anti-TLR2, but not anti-TLR4 in U937 cells. Further studies confirmed that MBP was able to directly bind to U937 and Jurkat cells and modulate TLR expression. The effects of MBP depended on the activation of NF-κB and MAP kinase in U937 and Jurkat cells.
  
  
  CONCLUSIONS
  Our results demonstrated that MBP could directly promote U937 cell viability via TLR2. It suggested that MBP may be used as an adjuvant for participating in the immunotherapy of haematologic malignancies.
authors.affiliation: Department of Immunology, Jilin University, 2 Xinmin Avenue, Changchun, Ji Lin 130021, People's Republic of China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Xiaoxia
authors.forename: Ni
authors.initials: N
authors.lastname: Weihua
authors.forename: Zhang
authors.initials: Z
authors.lastname: Qingyong
authors.forename: Wang
authors.initials: W
authors.lastname: Fengli
authors.forename: Li
authors.initials: L
authors.lastname: Yingying
authors.forename: Sun
authors.initials: S
authors.lastname: Xiaxia
authors.forename: Liu
authors.initials: L
authors.lastname: Zhonghui
authors.forename: Tai
authors.initials: T
authors.lastname: Guixiang
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D004926:Escherichia coli; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D019169:Jurkat Cells; D048670:MAP Kinase Kinase 4 / Q000235:genetics / Q000378:metabolism; D058619:Maltose-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D020298:U937 Cells; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D058619:Maltose-Binding Proteins; D012333:RNA, Messenger; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051996:Transcription Factor RelA; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4