Design of an epitope-based peptide vaccine againstCryptococcus neoformans

AbstractIntroductionThis study aimed to design an immunogenic epitope for Cryptococcus neoformans the etiological agent of cryptococcosis using in silico simulations, for epitope prediction, we selected the mannoprotein antigen MP88 which it’s known to induce protective immunity.Material & methodA total of 39 sequences of MP88 protein with length 378 amino acids were retrieved from the National Center for Biotechnology Information database (NCBI) in the FASTA format were used to predict antigenic B-cell and T cell epitopes via different bioinformatics tools at Immune Epitope Database and Analysis Resource (IEDB). The tertiary structure prediction of MP88 was created in RaptorX, and visualized by UCSF Chimera software.ResultA Conserved B-cell epitopesAYSTPA, AYSTPAS, PASSNCK, and DSAYPPhave displayed the most promising B cell epitopes. While theYMAADQFCL, VSYEEWMNYandFQQRYTGTFthey represent the best candidates T-cell conserved epitopes, the 9-mer epitopeYMAADQFCLdisplay the greater interact with 9 MHC-I alleles and HLA-A*02:01 alleles have the best interaction with an epitope. TheVSYEEWMNYandFQQRYTGTFthey are non-allergen whileYMAADQFCLwas an allergen. For MHC class II peptide binding prediction, theYARLLSLNA, ISYGTAMAVandINQTSYARLrepresent the most Three highly binding affinity core epitopes. The core epitopeINQTSYARLwas found to interact with 14 MHC-II. The allergenicity prediction revealsISYGTAMAV, INQTSYARLwere non-allergen andYARLLSLNAwas an allergen. Regarding population coverage theYMAADQFCLexhibit, a higher percentage among the world (69.75%) and the average population coverage was93.01%.In MHC-II,ISYGTAMAVepitope reveal a higher percentage (74.39%) and the average population coverage was (81.94%). This successfully designed a peptide vaccine against Cryptococcus neoformans open up a new horizon in Cryptococcus neoformans research; the results require validation by in vitro and in vivo experiments.