Antigenic similarity among group 1 allergens from grasses and quantitation ELISA using monoclonal antibodies to Phl p 1.
BACKGROUND
Group 1 allergens elicit a specific IgE response in about 90% of grass pollen-allergic patients. The aim of this work was to study the antigenic similarity among group 1 allergens from different grasses and to develop a monoclonal antibody (MAb)-based quantitation ELISA.


METHODS
Twenty specific MAbs were produced from BALB/c mice immunized with natural Phl p 1. These MAbs were tested for specificity with thirteen different grass pollen extracts from the Poaceae family and in cross-inhibition experiments for the binding of Phl p 1. Purified group 1 allergens from Poeae grasses (Dactylis glomerata, Lolium perenne, Festuca pratensis and Poa pratensis) were tested for parallelism in quantitation ELISA.


RESULTS
Eighteen to nineteen anti-Phl p 1 MAbs recognized the homologous allergen in pollen extracts from grasses of the Poeae tribe. In contrast, only four MAbs recognized group 1 from Cynodon dactylon and Phragmites communis. Four groups of MAbs with different epitope specificity were identified. A grass group 1 quantitation ELISA was developed using a mix of three MAbs on the solid phase and a polyclonal rabbit antibody as the second antibody. The group 1 content could be measured in different batches of Phleum pratense as well as in pollen extracts from Poeae grasses, since they showed parallel dose-response curves.


CONCLUSIONS
MAbs produced in this work enabled us to show the high antigenic similarity between group 1 allergens from temperate grasses. The results prove the usefulness of the ELISA method developed for standardization of grass allergen products.
Duffort
Oscar
O
ALK-Abelló, Research Department, Madrid, Spain.
Quintana
Juan
J
Ipsen
Henrik
H
Barber
Domingo
D
Polo
Florentino
F
D000485:Allergens / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D052179:Antigens, Plant / Q000276:immunology* / Q000378:metabolism; D001666:Binding Sites, Antibody; D002415:Cats; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D031784:Phleum / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology* / Q000378:metabolism; D006109:Poaceae / Q000276:immunology*; D011058:Pollen / Q000276:immunology
D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D010940:Plant Proteins; C090396:PHLPI protein, Phleum pratense