Expression of a 4-(hydroxy-3-nitro-phenyl) acetyl (NP) specific equi-murine IgE antibody that mediates histamine release in vitro and a type I skin reaction in vivo.
Due to characteristic clinical signs, immunoglobulins of isotype E (IgE) are believed to be involved in several allergic diseases of the horse. To date, closer investigations have been hampered by the fact that neither purified equine IgE nor anti-equine IgE monoclonal antibodies were available for IgE isotype determination. As an approach to solve this problem, we constructed a stable cell line (EqE6) that expresses recombinant equi-murine IgE specific for 4-(hydroxy-3-nitro-phenyl) acetyl (NP). Biochemical analysis of the purified protein revealed a highly glycosilated IgE monomer of approximately 230,000 Da. The biological ability of the NP-IgE to mediate histamine release after crosslinking with antigen was demonstrated in vitro using equine blood leucocytes. In vivo, the intradermal application of NP-IgE followed by antigen crosslinking induced a type I hypersensitivity skin reaction in horses. Both results indicate that the recombinant NP-IgE contains an intact and functional Fc(epsilon) RI binding site and mediates effector functions in equine basophils and cutaneous mast cells. This equi-murine IgE can be used for the production of IgE-specific polyclonal and monoclonal antibodies. In addition, the NP specificity allows the antigen-specific activation of equine Fc(epsilon)-receptor-expressing cells, such as mast cells and basophils. This property could be used to investigate IgE-mediated mechanisms for a better understanding of equine type I allergic diseases.
Wagner
B
B
Immunology, School of Veterinary Medicine, Hannover, Germany.
Siebenkotten
G
G
Leibold
W
W
Radbruch
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001491:Basophils / Q000276:immunology; D015153:Blotting, Western / Q000662:veterinary; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005260:Female; D006636:Histamine Release / Q000276:immunology*; D006734:Horse Diseases / Q000276:immunology*; D006736:Horses; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000662:veterinary*; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000737:chemistry / Q000276:immunology*; D008297:Male; D008407:Mast Cells / Q000276:immunology; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000276:immunology*; D010648:Phenylacetates; D016133:Polymerase Chain Reaction / Q000662:veterinary; D017455:Receptors, IgE / Q000276:immunology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D000911:Antibodies, Monoclonal; D009596:Nitrophenols; D010648:Phenylacetates; D017455:Receptors, IgE; C026242:4-hydroxy-5-nitrophenyl acetic acid; D007073:Immunoglobulin E