title: Evaluation of cell-surface IgE receptors on the canine mastocytoma cell line C2 maintained in continuous culture.
abstract: OBJECTIVE
  To assess expression and function of cell-surface IgE receptors on the canine mastocytoma cell line C2 maintained in continuous culture.
  
  
  METHODS
  C2 cells maintained in medium lacking IgE for up to 10 passages before being stored at -80 C.
  
  
  METHODS
  Cells were thawed, cultured in medium without IgE for 1 to 3 passages, sensitized for 7 days with IgE-rich serum from dogs naturally sensitized to Ascaris suum, and stimulated with antigen Asc S1 from A suum, goat polyclonal anti-canine IgE, or calcium ionophore and phorbol myristate acetate (PMA). Percentage of intracellular beta-hexosaminidase released and concentration of tumor necrosis factor-alpha (TNF-alpha) synthesized after stimulation were determined. Expression of cell-surface IgE receptors was assessed by use of a flow cytometry.
  
  
  RESULTS
  Immunologic stimulation (antigen or anti-IgE) failed to induce release or synthesis of detectable amounts of beta-hexosaminidase or TNF-alpha. In contrast, nonimmunologic stimulation (calcium ionophore and PMA) led to release of beta-hexosaminidase (mean +/- SEM maximum release, 23.95+/-1.96%) and synthesis of TNF-alpha (maximum concentration, 34.34+/-2.34 pg/10(6) cells). As revealed by use of flow cytometry, C2 cells expressed surface IgE receptors that bound canine IgE in vitro.
  
  
  CONCLUSIONS
  Continuous culture of the canine mastocytoma cell line C2 in medium without exogenous IgE or cytokines and other growth factors resulted in cell-surface expression of nonfunctional IgE receptors. However, C2 cells maintained in continuous culture may still be a useful tool for the evaluation of mast cell responses to nonimmunologic stimulation and IgE receptor differentiation and maturity.
authors.affiliation: Departament de Farmacologia, Facultat de Veterinària, Universitat Autònoma de Barcelona, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Brazís
authors.forename: Rosa
authors.initials: R
authors.lastname: Torres
authors.forename: Mireia
authors.initials: M
authors.lastname: Queralt
authors.forename: Fernando
authors.initials: F
authors.lastname: de Mora
authors.forename: Lluis
authors.initials: L
authors.lastname: Ferrer
authors.forename: Anna
authors.initials: A
authors.lastname: Puigdemont
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D017165:Ascaris suum / Q000276:immunology; D000001:Calcimycin / Q000494:pharmacology; D004285:Dogs / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry / Q000662:veterinary; D007476:Ionophores / Q000494:pharmacology; D012515:Mast-Cell Sarcoma / Q000276:immunology / Q000378:metabolism*; D017455:Receptors, IgE / Q000096:biosynthesis* / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D001619:beta-N-Acetylhexosaminidases / Q000096:biosynthesis
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007476:Ionophores; D017455:Receptors, IgE; D014409:Tumor Necrosis Factor-alpha; D000001:Calcimycin; D001619:beta-N-Acetylhexosaminidases; D013755:Tetradecanoylphorbol Acetate