In Silico Prediction And Their Preliminary Identification Trial In Vivo Of T Cell Epitopes In Secretory Antigens Of Schistosoma Japonicum

It has been one of the problems to be urgently solved to obtain the efficient and safe vaccine in the field of schistosomiasis control research. Many studies on immune mechanisms elucidated that the high protective immunity is mediated by CD4+T cell in radiation-attenuated (RA) cercariae mice models. It may possibly make a breakthrough for schistosome vaccine development to screening out protective antigens or T cell epitopes in RA mice models. Reverse vaccinology based on the principles of theories and experiments in immuno-informatics, can save much cost on time and money, and promise to be an effective tool in quick identification for the protective T cell epitopes of Schistosoma japonicum. The key problems to be solved of screening out protective antigens/epitopes by reverse vaccinology comprise: how to choose possible candidate molecules from large amounts of sequences; how to predict the MHC-binding peptides precisely. The present study carried out research work focused on aforementioned problems including the annotation of candidate sequences, the prediction and preliminary identification trial of T cell epitopes in 116 full length cDNA and 71 EST sequences of Schistosoma japonicum.Recognition for the coding region of DNA sequences is the premise of T cell epitopes identification. Whereas, there is no standard program for conventional laboratory use, this situation results in the differentiation of identification of coding region for a given sequence among laboratories. The present study analyzed the above samples by combining the sequence analyses of interior characteristics based on spectrum analysis and Markov Model with the ones of exterior characteristics on the identification of the start/stop sites of coding region, only 5% of the 116 full length cDNA sequences had differences between the results of our prediction and that of Chinese National Human Genome (South)Center s; 8.6% (and 1.7%) of all of the sequences with the same reading frame as South Center s prediction was short (and long) in length. The others were the same as their predictive results. 71 EST sequences were assembled into 51 non-redundent EST ( nr-EST) sequences, and the coding regions of above nr-EST sequences were also successfully identified. suggesting that the...