IgE and IgG4 binding to synthetic peptides of the cat (Felis domesticus) major allergen Fel dI.
Specificities of IgE and IgG4 antibodies in 12 cat-allergic patients were compared with respect to their reactivity towards 3 IgE-binding synthetic peptides of Felis domesticus allergen 1 (Fel dI): peptides 25-38 and 46-59 of chain 1 and peptide 15-28 of chain 2. Peptides were coupled to Sepharose and anti-Fel dI antibodies were isolated by affinity chromatography. Fel dI-specific IgE- and IgG4 antibody activity in the peptide eluates was measured using Fel dI binding assays. Fel dI-specific IgE/IgG4 ratios in the eluates from peptide-Sepharose were determined and compared with the IgE/IgG4 ratios in the eluates from Fel dI-Sepharose. The mean ratio Fel dI-specific IgE/IgG4 in the peptide eluates (0.84; range 0.06-4.6) was significantly higher than the mean ratio in the eluates from Fel dI-Sepharose (0.31; range 0.13-1.1), demonstrating a higher reactivity of IgE antibodies with the peptides, compared to IgG4. These results indicate differences between the B cells producing IgE antibodies and the B cells producing IgG4 antibodies.
van Milligen
F J
FJ
Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, University of Amsterdam.
van 't Hof
W
W
Aalberse
R C
RC
D000485:Allergens / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000032:analysis; D002415:Cats / Q000276:immunology*; D002846:Chromatography, Affinity; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000209:etiology; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism*; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000378:metabolism*; D011485:Protein Binding; D011852:Radioallergosorbent Test; D012685:Sepharose
D000485:Allergens; D000906:Antibodies; D006023:Glycoproteins; D007074:Immunoglobulin G; D010455:Peptides; D007073:Immunoglobulin E; D012685:Sepharose; C059296:Fel d 1 protein, Felis domesticus