The Recognition Of Ara By Antibody And Potential Therapy In Peanut Allergy

Food allergy is a kind of allergic disease often encountered in life,which has a big impact on people’s daily life.One of them is peanut allergy,and the prevalence of peanut allergy in children has reached 1.4% in 2008,and it is increasing every year.Many food allergies fade with growth,but peanut allergy doesn’t.There are many kinds of allergen proteins that cause peanut allergy,among which peanut antigen 1,2and 3(Ara h1,Ara h2 and Ara h3)are the most studied.In healthy people,the immune system remains unresponsive to non-allergenic food.While in individuals with food allergy,food allergens sensitize and lead to an inappropriate inflammatory immune response to common food.Food allergy belong to the Ig E-dependent Ⅰ type hypersensitivity,and the interactions of allergens and Ig E and high affinity FcεR Ⅰ receptor lead to mast cells degranulation,and the biological and chemical factors released cause allergic disease.The experimental plan is to elucidate the interaction of peanut antigen and Ig E antibody by a resolved the protein complex structure of them.On the other hand,the therapeutic effect is achieved by competitively blocking the allergic process with high affinity Ig E mutant and Ig G4 antibody.In this experiment,a single chain Ig E mutant antibody with higher affinity to Ara h3 but not very less affinity to Ara h2 was constructed by point mutation,and then a single chain Ig G4 antibody and peanut antigen Ara h3 were constructed by fully-gene synthesis.Then,the three proteins were expressed in the form of inclusion bodies.Then,the three proteins were expressed in the form of inclusion bodies,and sufficient proteins were obtained through refolding and dialysis.Then,proteins with good properties were purified by affinity chromatography and ion-exchange chromatography.Finally,antigen and antibody were incubated together to obtain protein complexes and some crystal kits were screened.Finally,it is planned to obtain protein complex crystals through crystal screening,so as to resolve their structure and know the way of their interaction.Finally,this experiment provide help for the explanation and treatment of peanut allergy.