Structural Study Of The Human Leukocyte Antigen And Drug Molecule Complex

Adverse drug reactions(ADRs)always happen during the usage of certain drugs.ADRs damage the victims' health and prevent the promotion of some effective drugs.Drug allergy is one kind of adverse drug reactions.Genome-wide association study shows that many severe drug allergies are greatly related with the HLA(Human Leukocyte antigen)allotypes of the patients.These HLA related drug allergies,also known as drug reaction with eosinophilia and systemic symptoms(DRESS),are often more severe in clinic and have high death rates.It is believed that drug molecules can interfere with the HLA or TCR(T cell receptor)during the antigen presenting process.The cytotoxic T cells are then activated and start to attack normal cells of our body,of which the direct results are the symptoms of DRESS.Carbamazepine is a prescribed drug used for epilepsy and neuropathic pain.It is wildly applied for its clinical curative effect and reasonable price.But it may cause serious DRESS symptoms like TEN/SJS.These diseases will lead to death if they are not treated timely and appropriately.Carbamazepine DRESS is found out to be highly related with the HLA-B*15:02 allele in Han Chinese,the Indian population and the Thai population.In vitro experiments also proved that specific cytotoxic T cells can lyse APCs(Antigen presenting cells)expressing HLA-B*15:02.In conclusion,our goal is to reveal the mechanism behind the HLA related Carbamazepine DRESS at atomic level.The crystal structure of the HLA protein-CBZ complex will give us information of the drug's location and explain the role of it.We have acquired the gene sequence of HLA through gene cloning and inserted the gene into a pET vector.E.coli was used for protein expression.Protein complexes were purified through affinity chromatography,ion-exchange chromatography or gel filtration.We got HLA-peptide protein complex samples of high purity(>95%)and quality after these processes.We used crystal screening assay kits for protein crystallization and optimization.A 0.5mm crystal was obtained.We collected the X-ray diffraction data of the crystal at Shanghai Synchrotron Radiation Facility(SSRF).The diffraction data was analyzed by computer programs.We got the crystal structure of the HLA-peptide complex after unremitting effort.We will continue our research by resolving the crystal structure of the HLA-peptide-Carbamazepine complex and compare it with the HLA-peptide complex.This will shed light on the mechanism of Carbamazepine DRESS and direct the research of DRESS caused by other drugs.These series of HLA and Carbamazepine crystal structures with precise 3D atomic coordinates are of great academic value as well as application value.They are guidance for related drug design or improvement and will give us a better understanding of the human immune system.