Immunological and biological properties of recombinant Lol p 1.
BACKGROUND
Current forms of allergy diagnosis and therapies are based on the use of natural allergenic extracts. Despite strong evidence that higher therapeutic efficacy may be achieved with purified allergens, the purification of multiple allergic components from extracts is a fastidious and sometimes an impossible task. However, the use of recombinant allergens may be an alternative to overcome this problem.


OBJECTIVE
In this study, we compared the immunological properties of recombinant (r) Lol p 1 with those of the natural protein.


METHODS
We cloned directly the gene encoding Lol p 1 from genomic DNA of ryegrass pollen. This gene was subcloned into the expression vector pMAL-c and expressed as fusion protein. Subsequently, rLol p 1 was cleaved from maltose-binding protein using factor Xa. Using binding inhibition and proliferative assays, we assessed the immunological properties of the recombinant allergens. The capacity of rLol p 1 to trigger basophil histamine release and to elicit a skin reaction was also assessed and compared to those of its natural counterpart.


RESULTS
We found that the Lol p 1 gene has no introns since we amplified this gene directly from genomic DNA. We demonstrated that the binding sites of anti-Lol p 1 monoclonal antibody, specific human IgG and IgE antibody are well conserved on rLol p 1 as no difference in the binding inhibition profile was observed when using either natural or recombinant protein. At the T-cell level, rLol p 1 elicited a T-cell response in mice comparable to that observed with the natural protein. In addition, we demonstrated that the biological characteristics of rLol p 1 were comparable to those of the natural counterpart, in that rLol p 1 elicited a skin wheal reaction and induced basophil histamine release in grass-allergic patients only.


CONCLUSIONS
The data indicate that natural Lol p 1 and rLol p 1 shared identical immunological and biological properties.
Boutin
Y
Y
Centre de Recherche en Immunologie et Rhumatologie, Centre Hospitalier de l'Université Laval and Immunova Ltd., Sainte-Foy, Québec, Canada.
Lamontagne
P
P
Boulanger
J
J
Brunet
C
C
Hébert
J
J
D000485:Allergens / Q000276:immunology*; D000818:Animals; D001491:Basophils / Q000378:metabolism; D003001:Cloning, Molecular; D018744:DNA, Plant; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D008129:Lolium / Q000235:genetics* / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D010940:Plant Proteins / Q000235:genetics* / Q000276:immunology*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012882:Skin Tests; D013601:T-Lymphocytes / Q000276:immunology
D000485:Allergens; D018744:DNA, Plant; D007074:Immunoglobulin G; D010940:Plant Proteins; D011994:Recombinant Proteins; D007073:Immunoglobulin E