Y. Boutin et al., IMMUNOLOGICAL AND BIOLOGICAL PROPERTIES OF RECOMBINANT LOL-P-1, International archives of allergy and immunology, 112(3), 1997, pp. 218-225
Background: Current forms of allergy diagnosis and therapies are based
on the use of natural allergenic extracts. Despite strong evidence th
at 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 recom
binant allergens may be an alternative to overcome this problem. Objec
tive: In this study, we compared the immunological properties of recom
binant (r) Lol p 1 with those of the natural protein. Method: We clone
d directly the gene encoding Lol p 1 from genomic DNA of ryegrass poll
en. This gene was subcloned into the expression vector pMAL(R)-c and e
xpressed as fusion protein. Subsequently, rLol p 1 was cleaved from ma
ltose-binding protein using factor Xa. Using binding inhibition and pr
oliferative assays, we assessed the immunological properties of the re
combinant allergens. The capacity of rLol p 1 to trigger basophil hist
amine release and to elicit a skin reaction was also assessed and comp
ared to those of its natural counterpart. Results: We found that the L
ol 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 mo
noclonal antibody, specific human IgG and IgE antibody are well conser
ved on rLol p 1 as no difference in the binding inhibition profile was
observed when using either natural or recombinant protein. At the T-c
ell level, rLol p 1 elicited a T-cell response in mice comparable to t
hat observed with the natural protein. In addition, we demonstrated th
at the biological characteristics of rLol p 1 were comparable to those
of the natural counterpart, in that rLol p 1 elicited a skin wheal re
action and induced basophil histamine release in grass-allergic patien
ts only. Conclusion: The data indicate that natural Lol p 1 and rLol p
1 shared identical immunological and biological properties.