title: Anti-CD63 antibodies suppress IgE-dependent allergic reactions in vitro and in vivo.
abstract: High-affinity IgE receptor (FcepsilonRI) cross-linking on mast cells (MCs) induces secretion of preformed allergy mediators (degranulation) and synthesis of lipid mediators and cytokines. Degranulation produces many symptoms of immediate-type allergic reactions and is modulated by adhesion to surfaces coated with specific extracellular matrix (ECM) proteins. The signals involved in this modulation are mostly unknown and their contribution to allergic reactions in vivo is unclear. Here we report the generation of monoclonal antibodies that potently suppress FcepsilonRI-induced degranulation, but not leukotriene synthesis. We identified the antibody target as the tetraspanin CD63. Tetraspanins are membrane molecules that form multimolecular complexes with a broad array of molecules including ECM protein-binding beta integrins. We found that anti-CD63 inhibits MC adhesion to fibronectin and vitronectin. Furthermore, anti-CD63 inhibits FcepsilonRI-mediated degranulation in cells adherent to those ECM proteins but not in nonadherent cells. Thus the inhibition of degranulation by anti-CD63 correlates with its effect on adhesion. In support of a mechanistic linkage between the two types of inhibition, anti-CD63 had no effect on FcepsilonRI-induced global tyrosine phosphorylation and calcium mobilization but impaired the Gab2-PI3K pathway that is known to be essential for both degranulation and adhesion. Finally, we showed that these antibodies inhibited FcepsilonRI-mediated allergic reactions in vivo. These properties raise the possibility that anti-CD63 could be used as therapeutic agents in MC-dependent diseases.
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kraft
authors.forename: Tony
authors.initials: T
authors.lastname: Fleming
authors.forename: James M
authors.initials: JM
authors.lastname: Billingsley
authors.forename: Shih-Yao
authors.initials: SY
authors.lastname: Lin
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Jouvin
authors.forename: Peter
authors.initials: P
authors.lastname: Storz
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Kinet
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D005340:Fibrinogen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D008407:Mast Cells / Q000166:cytology / Q000276:immunology; D010323:Passive Cutaneous Anaphylaxis; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D010980:Platelet Membrane Glycoproteins / Q000276:immunology*; D011493:Protein Kinase C / Q000378:metabolism; D051745:Protein Kinase C-delta; D051381:Rats; D017455:Receptors, IgE / Q000276:immunology*; D012701:Serotonin / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D060149:Tetraspanin 30; D014443:Tyrosine / Q000378:metabolism; D019096:Vitronectin / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C554586:CD63 protein, human; C554588:Cd63 protein, rat; D005353:Fibronectins; C490895:GAB2 protein, human; D010750:Phosphoproteins; D010980:Platelet Membrane Glycoproteins; D017455:Receptors, IgE; D060149:Tetraspanin 30; D019096:Vitronectin; D012701:Serotonin; D007073:Immunoglobulin E; D014443:Tyrosine; D005340:Fibrinogen; C497260:Prkcd protein, rat; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D002118:Calcium