DESIGN OF AN EPITOPE-BASED PEPTIDE VACCINE AGAINST CRYPTOCOCCUS NEOFORMANS
Isra Khalil1, Ibtihal Omer1, Islam Zainalabdin Abdalgadir Farh2, Hanaa Abdalla Mohamed1, Hajr Abdallha Elsharif3, ALazza Abdalla Hassan Mohamed4, Mawadda Abd-Elraheem Awad-Elkareem5 and Mhamed Ahmed Salih6
1Department of Microbiology, Sudan University of Science and Technology, Khartoum, Sudan
2University of Khartoum Faculty of Dentistry, Khartoum, Sudan
3General Administration of quarantine and Animal Health. Regional Training Institute.
4 Department of biotechnology, Omdurmam Islamic University, Faculty of science and technology
5Department of Biotechnology, Ahfad University for Women, Omdurman, Sudan
6Department of Biotechnology, Africa City of Technology, Khartoum, Sudan
This 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.
A 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.
A Conserved B-cell epitopes AYSTPA, AYSTPAS, PASSNCK, and DSAYPP have displayed the most promising B cell epitopes. While the YMAADQFCL, VSYEEWMNY and FQQRYTGTF they represent the best candidates T-cell conserved epitopes, the 9-mer epitope YMAADQFCL display the greater interact with 9 MHC-I alleles and HLA-A*02:01 alleles have the best interaction with an epitope. The VSYEEWMNY and FQQRYTGTF they are non-allergen while YMAADQFCL was an allergen. For MHC class II peptide binding prediction, the YARLLSLNA, ISYGTAMAV and INQTSYARL represent the most Three highly binding affinity core epitopes. The core epitope INQTSYARL was found to interact with 14 MHC- II. The allergenicity prediction reveals ISYGTAMAV, INQTSYARL were non-allergen and YARLLSLNA was an allergen. Regarding population coverage the YMAADQFCL exhibit a higher percentage among the world (69.75%) and the average population coverage was 93.01%. In MHC- II, ISYGTAMAV epitope 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.