Reduction of allergenicity of litchi chinensis flowers pollen protein

Background: Allergy to pollen from
gymnosperms is well documented in the
west. The objective was to define the
allergologic protein from Litchi chinensis
(Litchi) pollen and conjugate the protein
with polysaccharides by Maillard reaction
to reduce the allergic effect of that
protein.
Methods: Total soluble proteins were
extracted from the pollen of Litchi flower
pollen and subjected to ammonium
sulphate precipitation at 80% saturation.
Pollen antigen from Litchi chinensis
(Litchi) was prepared by gel cutting
method and characterized by biochemical
and designated by LFPP. The
homogeneity of this protein was
demonstrated by a single band on SDSPAGE.
The protein then conjugated with
galactomannan through Maillard
Reaction. The resulting purified pollen
protein and conjugated protein were
administrered to the swiss albino mice as
amount of 5.8mg/kg body weight.
Results: The total protein was then
separated on a 12% SDS-Polyacrylamide
gel which revealed 5 bands between
molecular weight range of 29 kDa and 69
kDa. Each band was recovered from the
gel by electroelution and sent for skin
tests. 28 kDa proteins was the only
allergenic protein while others were not
shown reactivity in patients.
Intraperitoneal injection of the purified
protein (LFPP) caused a significant rise
in the levels of neutrophils (38-81%) and
eosinophils (3-14%) compared to control
(P<0.001) whereas conjugated protein
caused only a 2% increase of both
neutrophils and eosinophils level. On the
other hand treatment with LFPPgalactomannan
conjugate causes no such
change in physical appearance with
eosinophils and neutrophils level.
Conclusion: The present study
demonstrates that the protein extracted
and purified from Litchi flowers pollen
has been recognized as a new allergen
from Bangladesh for the first time and the
allergic effects can be reduced by
conjugation with polysaccharides.