title: Heat shock cognate protein 70 contributes to Brucella invasion into trophoblast giant cells that cause infectious abortion.
abstract: BACKGROUND
  The cell tropism of Brucella abortus, a causative agent of brucellosis and facultative intracellular pathogen, in the placenta is thought to be a key event of infectious abortion, although the molecular mechanism for this is largely unknown. There is a higher degree of bacterial colonization in the placenta than in other organs and many bacteria are detected in trophoblast giant (TG) cells in the placenta. In the present study, we investigated mechanism of B. abortus invasion into TG cells.
  
  
  RESULTS
  We observed internalization and intracellular growth of B. abortus in cultured TG cells. A monoclonal antibody that inhibits bacterial internalization was isolated and this reacted with heat shock cognate protein 70 (Hsc70). Depletion and over expression of Hsc70 in TG cells inhibited and promoted bacterial internalization, respectively. IFN-gamma receptor was expressed in TG cells and IFN-gamma treatment enhanced the uptake of bacteria by TG cells. Administering the anti-Hsc70 antibody to pregnant mice served to prevent infectious abortion.
  
  
  CONCLUSIONS
  B. abortus infection of TG cells in placenta is mediated by Hsc70, and that such infection leads to infectious abortion.
authors.affiliation: Department of Veterinary Public Health, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan. s11042@st.obihiro.ac.jp
authors.forename: Kenta
authors.initials: K
authors.lastname: Watanabe
authors.forename: Masato
authors.initials: M
authors.lastname: Tachibana
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Furuoka
authors.forename: Motohiro
authors.initials: M
authors.lastname: Horiuchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Masahisa
authors.initials: M
authors.lastname: Watarai
mesh_terms: D000031:Abortion, Septic / Q000378:metabolism / Q000382:microbiology* / Q000517:prevention & control; D000595:Amino Acid Sequence; D000818:Animals; D002003:Brucella abortus / Q000472:pathogenicity* / Q000502:physiology; D002006:Brucellosis / Q000378:metabolism* / Q000382:microbiology / Q000517:prevention & control; D002478:Cells, Cultured; D005260:Female; D050883:HSC70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D011247:Pregnancy; D014327:Trophoblasts / Q000378:metabolism* / Q000382:microbiology; D014774:Virulence
chemical_list: D050883:HSC70 Heat-Shock Proteins; C494372:Hspa8 protein, mouse; D007371:Interferon-gamma