title: IL-4 induces the formation of multinucleated giant cells and expression of β5 integrin in central giant cell lesion.
abstract: BACKGROUND
  It is now well established that IL-4 has a central role in the development of monocytes to multinucleated giant cells (MGCs) by inducing the expression of integrins on the surface of monocytes. The aim of this study was to investigate the potential role of IL-4 in induction of β5 integrin expression in the peripheral blood samples of patients with giant cell granuloma.
  
  
  METHODS
  Monocytes were isolated from peripheral blood samples of patients with central giant cell granuloma (CGCG) and healthy controls using human Monocyte Isolation Kit II. Isolated monocytes were then cultured in the absence or presence of IL-4 (10 and 20 ng/mL), and following RNA extraction and cDNA synthesis, Real-time PCR was performed to determine the level of β5 integrin expression. The formation of CGCGs and morphological analyses were done under light microscopy. For confirmation of CGCGs, immunocytochemistry technique was also carried out by anti-RANK (receptor-activator of NF-κB ligand) antibody.
  
  
  RESULTS
  In both patient and control groups, β5 levels were significantly enhanced by increasing the IL-4 dose from 10 to 20 ng/mL. In addition, these differences were significant between patient and control groups without IL-4 treatment. On the other hand, the number of cells which expressed RANK and therefore the number of giant cells were significantly higher in the patient group in comparison to controls, as assessed by immunohistochemistry evaluations.
  
  
  CONCLUSIONS
  In this study, we showed an elevation in the expression levels of β5 integrin when stimulated by IL-4. It is strongly indicated that this integrin acts as an important mediator during macrophage to macrophage fusion and development of giant cells.
authors.affiliation: Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. mkoohsoltani@yahoo.com.
authors.forename: A
authors.initials: A
authors.lastname: Aghbali
authors.forename: S
authors.initials: S
authors.lastname: Rafieyan
authors.forename: L
authors.initials: L
authors.lastname: Mohamed-Khosroshahi
authors.forename: B
authors.initials: B
authors.lastname: Baradaran
authors.forename: D
authors.initials: D
authors.lastname: Shanehbandi
authors.forename: M
authors.initials: M
authors.lastname: Kouhsoltani
mesh_terms: D002478:Cells, Cultured; D015726:Giant Cells / Q000166:cytology*; D006101:Granuloma, Giant Cell / Q000097:blood*; D006801:Humans; D039641:Integrin beta Chains / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000502:physiology*; D009000:Monocytes / Q000378:metabolism*
chemical_list: D039641:Integrin beta Chains; C084344:integrin beta5; D015847:Interleukin-4