Rotavirus Cross-immune Response Of Live Attenuated Vaccine

Rotavirus (RV) is the leading pathogen of severe diarrhea in infants and young children worldwide,also is one of main cause leaing to deaths in the developing countries.There are no effective drugs to cure the disease,as a result, the strategy for developing an effective oral rotavirus vaccine involving the use of live,attenuated strains which should protect an infant by the same mechanism as natural infection[1] has been an international goal in the last decades.As the development of prophylactic vaccines, some attenuated live rotavirus vaccines have gotten into the market,whether the monovalent or the non-monovalent is significantly reduce the incidence of rotavirus gastroenteritis,which serotype can protect the body from maximum range.Recent sudies have revealed unusual combinations of different serotypes beween human and animals in various countries where they believe these strange combinations have possibly emerged because of reassortment. Since there is no consistent statement,and lacking of the fundamental research ,it is difficult to evaluate the vaccines,so we start this project to solve this problem.Two kinds of commercial rotavirus vaccines, which are the monovalent human rotavirus vaccine (Rotarix) in GSK, and the monovalent lamb rotavirus vaccine (LLR) in the institute of biologic products in Lanzhou and other four rotavirus strain,which are Wa(G1),DS-1(G2),SA11(G3)andST-3(G4) were used to sudy rotavirus immunity and cross protection.This study approached to three subjects.The first part is to study the immunity and cross protection among the different strains,mainly use the serum against LLR and Rotarix to test the other Rotavirus strains;the second part,we use 12-mer Phage display technique to identify post-immun quail serum to provide new ideas of direct-evolution for understanding LLR-induced antibody, The DNA of these phage clones were extracted for sequencing as described in manual.The peptide sequences were deduced from DNA sequences.Those peptides were analysed by bioinformatics.Through Blast,the peptide sequences were compared for homology analysis;the third part in this thesis is to express rotavirus structural protein VP5,VP6,VP7andVP8 in Escherichia coli..All study can provide fundmental guidline to develop and evaluate new rotavirus vaccines.