TY - JOUR
T1 - The molecular basis of antigenic cross-reactivity between the group 2 mite allergens
AU - Smith, A.M.
AU - Benjamin, D.C.
AU - Hozic, N.
AU - Derewenda, U.
AU - Smith, W.A.
AU - Thomas, Wayne
AU - Gafvelin, G.
AU - Van Hage-Hamsten, M.
AU - Chapman, M.D.
PY - 2001
Y1 - 2001
N2 - Background: Mite group 2 allergens Der p 2, Der f 2, and fur m 2 are 14-kDa proteins of unknown function that share 83% to 85% amino acid sequence identity. Isoforms of the allergens within each genus have been identified which differ by 3 or 4 amino acids, but little is known of the influence of group 2 polymorphisms on human IgE antibody binding.Objective: The purpose of this study was to investigate the importance of interspecies and isoform substitutions on murine mAb and IgE antibody binding and on the molecular structure of the group 2 allergens.Methods: Site-directed mutagenesis was used to incorporate the isoform amino acid substitutions onto the Der p 2.0101 sequence. Recombinant allergens were expressed and purified from Escherichia coli and used to evaluate antibody binding by enzyme-linked immunosorbent assay (ELISA). Molecular modeling of the tertiary structure was used to analyze structural differences between the various group 2 allergens.Results: The substitution of asparagine for aspartic acid at position 114 restored mAb binding of rDer p 2.0101; the other Der p 2 isoforms and the 3 rDer f 2 isoforms also reacted in the 2-site ELISA. The correlation of IgE binding to the Der p 2 isoforms was excellent and tended to be higher in the isoforms with the asparagine 114 substitution (r(2) = 0.87 vs r(2) = 0.95), rEur m 2.0101 bound to all mAb except 7A1: when compared with rDer p 2 for IgE binding, rEur m 2.0101 gave a correlation coefficient of r(2) = 0.68. Molecular modeling revealed that fur m 2 and the storage mite homologs Lep d 2 and Tyr p 2 retain the tertiary fold of Der p 2. fur m 2 has a conserved surface, whereas Lep d 2 and Tyr p 2 present most of the amino acid substitutions on this surface. Lep d 2 and Tyr p 2 did not react with mAb or with sera from patients with IgE to Dermetophagoides species.Conclusion: The isoform substitutions of rDer p 2 can be distinguished by mAb. The allergenic cross-reactivity between Der p 2, Der f 2, and fur m 2 is a direct result of the conserved antigenic surface, whereas the lack of cross-reactivity with Lep d 2 and Sr p 2 is a result of the multiple substitutions across this surface.
AB - Background: Mite group 2 allergens Der p 2, Der f 2, and fur m 2 are 14-kDa proteins of unknown function that share 83% to 85% amino acid sequence identity. Isoforms of the allergens within each genus have been identified which differ by 3 or 4 amino acids, but little is known of the influence of group 2 polymorphisms on human IgE antibody binding.Objective: The purpose of this study was to investigate the importance of interspecies and isoform substitutions on murine mAb and IgE antibody binding and on the molecular structure of the group 2 allergens.Methods: Site-directed mutagenesis was used to incorporate the isoform amino acid substitutions onto the Der p 2.0101 sequence. Recombinant allergens were expressed and purified from Escherichia coli and used to evaluate antibody binding by enzyme-linked immunosorbent assay (ELISA). Molecular modeling of the tertiary structure was used to analyze structural differences between the various group 2 allergens.Results: The substitution of asparagine for aspartic acid at position 114 restored mAb binding of rDer p 2.0101; the other Der p 2 isoforms and the 3 rDer f 2 isoforms also reacted in the 2-site ELISA. The correlation of IgE binding to the Der p 2 isoforms was excellent and tended to be higher in the isoforms with the asparagine 114 substitution (r(2) = 0.87 vs r(2) = 0.95), rEur m 2.0101 bound to all mAb except 7A1: when compared with rDer p 2 for IgE binding, rEur m 2.0101 gave a correlation coefficient of r(2) = 0.68. Molecular modeling revealed that fur m 2 and the storage mite homologs Lep d 2 and Tyr p 2 retain the tertiary fold of Der p 2. fur m 2 has a conserved surface, whereas Lep d 2 and Tyr p 2 present most of the amino acid substitutions on this surface. Lep d 2 and Tyr p 2 did not react with mAb or with sera from patients with IgE to Dermetophagoides species.Conclusion: The isoform substitutions of rDer p 2 can be distinguished by mAb. The allergenic cross-reactivity between Der p 2, Der f 2, and fur m 2 is a direct result of the conserved antigenic surface, whereas the lack of cross-reactivity with Lep d 2 and Sr p 2 is a result of the multiple substitutions across this surface.
U2 - 10.1067/mai.2001.115629
DO - 10.1067/mai.2001.115629
M3 - Article
C2 - 11398074
SN - 0091-6749
VL - 107
SP - 977
EP - 984
JO - Journal of Allergy and Clinical Immunology
JF - Journal of Allergy and Clinical Immunology
ER -