Suppression of allergen-specific B lymphocytes by chimeric protein-engineered antibodies

Abstract

House dust mites Dermatophagoides pteronyssinus (Dpt) are among the most frequent causes of allergy symptoms in Europe. Der p 1 is one of the major allergenic compounds of Dpt and the pathological Der p 1-specific B cells play a key role as producers of allergen-binding antibodies. The selective elimination of these cells by artificial protein molecules which inhibit the production of Dpt-recognizing IgE antibodies is a perspective therapeutic goal of allergy. A protein engineered chimeric molecule has been constructed, which binds Der p 1-specific B cells via their BCR and suppresses selectively the production of anti-Der p 1 antibodies via CR1. The synthetic peptide Der p 1 p52-71 and an anti-CD35 monoclonal antibody were used for the construction of Der p 1 chimera. The functional effects of engineered antibodies were analyzed in vitro using PBMCs from allergy patients. Significant inhibition of allergen-specific proliferation and reduction of Der p 1-IgE antibody production were observed after treatment of PBMCs from allergic patients with Der p 1-peptide chimera. Culturing of these PBMCs in the presence of the chimeric molecule increased the percentage of apoptotic (Annexin V-positive) B lymphocytes, but not T lymphocytes.

Keywords: 1-ethyl-3(3′-dimethylaminopropyl; 5-bromo-4-chloro-3-indolyl phosphate; Allergen-specific B lymphocytes; Allergy; B cell receptor; BCIP; BCR; CR1; Dermatophagoides pteronyssinus; Dpt; EDC; ELISA; ELISpot; FACS; FCS; FITC; HDM; IFN-γ; NBT; PBMCs; PE; Protein chimera; SCID; SD; SDS-PAGE; SIT; SLE; complement receptor 1; double stranded DNA; dsDNA; enzyme-linked immuno-sorbent analysis; enzyme-linked immunosorbent spot; fetal calf serum; fluorescein isothiocyanate; fluorescence-activated cell sorting; house dust mite; interferon gamma; mAb; monoclonal antibody; nitro blue tetrazolium; peripheral blood mononuclear cells; phicoerythrin; scFv; severe combined immunodeficiency; single chain Fv; sodium dodecyl sulfate-polyacrylamide gel electrophoresis; specific immunotherapy; standard deviation; systemic lupus erythematosus.