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Targeted elimination of cells expressing the high‐affinity receptor for IgE (FcϵRI) by a Pseudomonas exotoxin‐based chimeric protein
Author(s) -
Fishman Ala,
LorberboumGalski Haya
Publication year - 1997
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830270220
Subject(s) - pseudomonas exotoxin , biology , fusion protein , microbiology and biotechnology , exotoxin , immunoglobulin e , complementary dna , fragment crystallizable region , effector , receptor , antibody , cytotoxicity , recombinant dna , immunology , biochemistry , toxin , gene , in vitro
Abstract The interaction between IgE and its high‐affinity receptor FcϵRI found on mast cells and basophils is the primary effector pathway in allergic response. To achieve a targeted elimination of cells expressing FcϵRI receptors, we constructed a chimeric protein in which a Fc fragment of mouse IgE is attached to a truncated form of Pseudomonas exotoxin (PE). To prepare the targeting moiety, we used a DNA sequence corresponding to amino acids 301–437, representing 30 residues of domain 2 and domain 3 of the mouse IgE constant region. This sequence was fused at the 5′ of a cDNA encoding PE 40 , a truncated form of PE lacking the cell binding domain. The chimeric protein, termed Fc 2′−3 −PE 40 , was expressed in Escherichia coli and partially purified. The protein is highly cytotoxic to mouse mast cell lines and bone marrow‐derived primary mast cells. This cytotoxicity is specific, as it could be blocked upon addition of whole IgE. Moreover, the protein had no effect on other cell lines of hemopoietic origin. The Fc 2′−3 −PE 40 chimeric protein offers a new approach to the treatment of allergic disorders.