title: Presence of an antigenic determinant common to rat IgE-potentiating factor, IgE-suppressive factor, and Fc epsilon receptors on T and B lymphocytes.
abstract: Polyclonal antibodies against purified IgE-potentiating factor were prepared in guinea pigs, and mouse monoclonal antibodies were prepared against inactive IgE-binding factor from a T cell hybridoma. The polyclonal antibodies and two of the monoclonal antibodies bound the IgE-potentiating factor, the IgE suppressive factor, and the inactive IgE-binding factor. The results indicate that the three IgE-binding factor molecules share a common antigenic determinant. The polyclonal antibodies and the monoclonal antibody bound intracellular IgE-binding factors that did not have affinity for either lentil lectin or peanut agglutinin, which suggests that the antibodies were directed against the peptide portion of IgE-binding factors. Pretreatment of Fc epsilon R+ T hybridoma cells and Fc epsilon R+ B cells with either the monoclonal or the polyclonal anti-IgE-binding factor (anti-IgE-bF) antibody prevented rosette formation of the cells with IgE-coated erythrocytes, whereas the same treatment failed to affect rosette formation of Fc gamma R+ cells with IgG-coated erythrocytes. Specific binding of the guinea pig anti-IgE-bF antibodies to Fc epsilon R on both B and T cells was confirmed by immunofluorescence. The results indicate that Fc epsilon R on B and T cells share a common antigenic determinant with IgE-binding factors. The F(ab')2 fragments of the guinea pig anti-IgE-bF induced the expression of Fc epsilon R on Fc gamma R+ lymphocytes and the formation of IgE-binding factors. The capacities of not only IgE, but also anti-IgE-bF, to induce both Fc epsilon R expression and IgE-binding factor formation indicate that Fc epsilon R on lymphocytes, rather than IgE, transmit the signal for the formation of IgE-binding molecules.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001798:Blood Proteins / Q000096:biosynthesis / Q000276:immunology*; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology*; D006168:Guinea Pigs; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008222:Lymphokines / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D011917:Rats, Inbred Lew; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D011961:Receptors, Fc / Q000096:biosynthesis / Q000276:immunology*; D017455:Receptors, IgE; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000276:immunology*; D013491:Suppressor Factors, Immunologic
chemical_list: D000911:Antibodies, Monoclonal; D001798:Blood Proteins; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D008222:Lymphokines; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell; D011961:Receptors, Fc; D017455:Receptors, IgE; D011971:Receptors, Immunologic; D013491:Suppressor Factors, Immunologic; C011850:immunoenhancing factor