title: Leukocyte-specific CCL3 deficiency inhibits atherosclerotic lesion development by affecting neutrophil accumulation.
abstract: OBJECTIVE
  Despite common disbelief that neutrophils are involved in atherosclerosis, evidence is accumulating for a causal role of neutrophils in atherosclerosis. CC chemokine ligand (CCL)3 is an inflammatory chemokine and its expression is significantly increased during atherosclerotic lesion formation in mice. It has recently been shown that under conditions of inflammation neutrophils can migrate along a CCL3 gradient. In this study, we aimed to elucidate the role of leukocyte-derived CCL3 in atherogenesis.
  
  
  RESULTS
  Irradiated low density lipoprotein receptor(-/-) mice, reconstituted with CCL3(-/-) or littermate bone marrow showed markedly reduced CCL3 response to lipopolysaccharide treatment, establishing the critical relevance of leukocytes as source of CCL3. Hematopoietic deficiency of CCL3 significantly reduced aortic sinus lesion formation by 31% after 12 weeks of western-type diet. Interestingly, whereas plaque macrophage, collagen, and vascular smooth muscle cell content were unchanged, neutrophil adhesion to and presence in plaques was significantly attenuated in CCL3(-/-) chimeras. These mice had reduced circulating neutrophil numbers, which could be ascribed to an increased neutrophil turnover and CCL3(-/-) neutrophils were shown to be less responsive toward the neutrophil chemoattractant CXC chemokine ligand 1.
  
  
  CONCLUSIONS
  Our data indicate that under conditions of acute inflammation leukocyte-derived CCL3 can induce neutrophil chemotaxis toward the atherosclerotic plaque, thereby accelerating lesion formation.
authors.affiliation: Division of Biopharmaceutics, Leiden Academic Center for Drug Research, Gorlaeus Laboratories, Leiden University, Leiden, the Netherlands. s.de.jager@lacdr.leidenuniv.nl
authors.forename: Saskia C A
authors.initials: SC
authors.lastname: de Jager
authors.forename: Ilze
authors.initials: I
authors.lastname: Bot
authors.forename: Adriaan O
authors.initials: AO
authors.lastname: Kraaijeveld
authors.forename: Suzanne J A
authors.initials: SJ
authors.lastname: Korporaal
authors.forename: Martine
authors.initials: M
authors.lastname: Bot
authors.forename: Peter J
authors.initials: PJ
authors.lastname: van Santbrink
authors.forename: Theo J C
authors.initials: TJ
authors.lastname: van Berkel
authors.forename: Johan
authors.initials: J
authors.lastname: Kuiper
authors.forename: Erik A L
authors.initials: EA
authors.lastname: Biessen
mesh_terms: D000818:Animals; D017209:Apoptosis; D016026:Bone Marrow Transplantation; D002340:Carotid Artery Diseases / Q000235:genetics / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D017536:Carotid Artery, Common / Q000276:immunology* / Q000473:pathology; D002448:Cell Adhesion; D002478:Cells, Cultured; D054405:Chemokine CCL3 / Q000172:deficiency* / Q000235:genetics; D054360:Chemokine CXCL1 / Q000378:metabolism; D002634:Chemotaxis, Leukocyte; D003520:Cyclophosphamide; D004041:Dietary Fats; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D007962:Leukocytes / Q000276:immunology*; D008070:Lipopolysaccharides; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009503:Neutropenia / Q000139:chemically induced / Q000276:immunology; D020556:Neutrophil Infiltration; D009504:Neutrophils / Q000276:immunology*; D058226:Plaque, Atherosclerotic; D012333:RNA, Messenger / Q000378:metabolism; D011973:Receptors, LDL / Q000172:deficiency / Q000235:genetics; D013997:Time Factors; D014916:Whole-Body Irradiation
chemical_list: C496534:Ccl3 protein, mouse; D054405:Chemokine CCL3; D054360:Chemokine CXCL1; D004041:Dietary Fats; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011973:Receptors, LDL; D003520:Cyclophosphamide