title: Interleukin-33 augments Treg cell levels: a flaw mechanism in atherosclerosis.
abstract: BACKGROUND
  Atherosclerosis is a well-established inflammatory disease in which T helper 1 (Th1) cells play a key role. Regulatory T (Treg) cells drive a shift from Th1 to Th2 response and were shown to be reduced in atherosclerosis. ST2/interleukin (IL)-33 signal was found to promote Th2 response, attenuating atherosclerotic plaque progression.
  
  
  OBJECTIVE
  To evaluate the effect of IL-33 on Treg cell number.
  
  
  METHODS
  We employed flow cytometry to determine Treg cell number, as well as ST2 levels, among splenocytes of C57BL/61 vs ApoE-/- mice. Soluble ST2 (sST2) levels were detected by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  IL-33 contributed to an increase in Treg cells, but this association was attenuated in ApoE knockout (ApoE-/-) atherosclerotic mice. As a possible mechanism we demonstrated a reduction in the levels of CD4+ST2+ cells by flow cytometry, which is cotemporary to the previously described decrease in Treg cells in ApoE-/- mice. Additionally, the serum level of the soluble ST2 (sST2) decoy receptor was higher in ApoE-/- mice than in control animals.
  
  
  CONCLUSIONS
  Our results suggest that a repressed ST2/ IL-33 signaling may contribute to the decrease in Treg cells observed in atherosclerosis.
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Asaf
authors.initials: A
authors.lastname: Wasserman
authors.forename: Jeremy
authors.initials: J
authors.lastname: Ben-Shoshan
authors.forename: Michal
authors.initials: M
authors.lastname: Entin-Meer
authors.forename: Sofia
authors.initials: S
authors.lastname: Maysel-Auslender
authors.forename: Hanan
authors.initials: H
authors.lastname: Guzner-Gur
authors.forename: Gad
authors.initials: G
authors.lastname: Keren
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000097:blood / Q000276:immunology* / Q000473:pathology; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D007111:Immunity, Cellular; D000067596:Interleukin-33; D007378:Interleukins / Q000097:blood*; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
chemical_list: C506535:Il33 protein, mouse; D000067596:Interleukin-33; D007378:Interleukins