title: Expression of the chemokine receptor CCR3 on human mast cells.
abstract: BACKGROUND
  The aim of this study was to investigate whether human mast cells express functional active CCR3 receptors, which are activated by CC chemokines. These ligands include the CCR3-selective chemokines eotaxin and eotaxin-2 and the more promiscuous CC chemokines, MCP-4, MCP-3, MCP-2 and RANTES.
  
  
  METHODS
  Immunohistochemical analysis was performed on skin, gut and lung specimens. Double immunostaining was performed with anti-CCR3 and antitryptase, and anti-CCR3 and antichymase antibody (Ab) by using the avidin-biotin-peroxidase system with two different substrates. Mast cells were isolated and purified from human lung parenchyma (HLMC) by countercurrent elutriation followed by discontinuous Percoll density gradient. Flow-cytometric analysis of HLMC surface CCR3 expression was performed with the monoclonal Ab anti-CCR3 (7B11). Functional activation of HLMC was verified by the ability of cells to release histamine and/or migrate in response to eotaxin.
  
  
  RESULTS
  High percentages (>70%) of tryptase-positive cells showing CCR3 expression were found in the skin and in the intestinal submucosa, whereas much lower percentages (< or = 20%) were found in the intestinal mucosa and in the lung interstitium. Eotaxin (1-100 nM) neither induced histamine release from HLMC nor enhanced anti-IgE-induced histamine release. In contrast, eotaxin (10-100 nM) and RANTES (10-100 nM) induced HLMC chemotaxis in vitro. Preincubation of HLMC with antibody anti-CCR3 (5 microg/ml) before loading into the chemotaxis chamber abrogated chemotaxis elicited by eotaxin. Double immunostaining with anti-CCR3 and anti-chymase antibody showed that the vast majority of CCR3-expressing mast cells in the various human tissues examined were tryptase-chymase double-positive.
  
  
  CONCLUSIONS
  These results indicate that CCR3 is expressed on human mast cells and that these cells are attracted by CCR3-binding chemokines.
authors: Division of Clinical Immunology and Allergy, University of Naples Federico II, Naples, Italy.
authors: A
authors: A
authors: de Paulis
authors: F
authors: F
authors: Annunziato
authors: L
authors: L
authors: Di Gioia
authors: S
authors: S
authors: Romagnani
authors: M
authors: M
authors: Carfora
authors: C
authors: C
authors: Beltrame
authors: G
authors: G
authors: Marone
authors: P
authors: P
authors: Romagnani
mesh_terms: D002478:Cells, Cultured; D054413:Chemokine CCL11; D018946:Chemokine CCL5 / Q000494:pharmacology; D019742:Chemokines, CC; D002633:Chemotaxis; D016207:Cytokines / Q000494:pharmacology; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D054397:Receptors, CCR3; D019707:Receptors, Chemokine / Q000378:metabolism*; D012867:Skin / Q000378:metabolism
chemical_list: C515456:CCL11 protein, human; C515350:CCR3 protein, human; D054413:Chemokine CCL11; D018946:Chemokine CCL5; D019742:Chemokines, CC; D016207:Cytokines; D054397:Receptors, CCR3; D019707:Receptors, Chemokine