Elsideeq E. M. Eltilib¹, Yassir A. Almofti^1,, Khoubieb Ali Abd-elrahman², Mashair A. A. Nouri¹

Noroviruses are the leading cause of acute gastroenteritis and is responsible for approximately 685 million cases and 200,000 deaths annually worldwide. Currently, there is no vaccine to prevent human norovirus infection, and there is no specific therapy available to treat it. This study aimed to predict epitopes from the capsid VP1 protein that elicited the immune system and acted as safer efficacious vaccine. A total of 21 noroviurse strains were retrieved from the NCBI database. The IEDB analysis resources were used for epitopes prediction against B and T cells. The population coverage was calculated for the proposed epitopes against the whole world. Eight epitopes (₄₈QVNP₅₁, ₁₅₉EVPLE₁₆₃, ₂₂₄VEQK₂₂₇, ₂₄₅RAPLP₂₄₉, ₃₇₆ISPPS₃₈₀, ₄₀₉VYPP₄₁₂, ₄₇₃FKAY₄₇₆ and ₄₉₂PQQLP₄₉₆) successfully passed all B cell prediction tools and were shown to be antigenic, nonallergic and nontoxic. Thus were proposed as B cells epitopes. For cytotoxic T cells, a total of 103 epitopes were found to interact with MHC-I alleles. However, only 22 epitopes were shown to be antigenic, nonallergic and nontoxic. Among them four epitopes namely (_140-AQATLFPHV-₁₄₈; _216-FLFLVPPTV_-224; _499-GVFVFVSWV_-507 and _410-YPPGFGEVL_-418) interacted with high number of MHC-I alleles and demonstrated favourable population coverage and thus were proposed as cytotoxic T lymphocytes MHC-1 epitopes. Moreover helper T cells, a total of 421 core epitopes were found to interact with MHC-П alleles. However, only 105 epitopes were shown to be antigenic, nonallergic and nontoxic. Eight epitopes namely (_216-FLFLVPPTV_-224; _499-GVFVFVSWV_-507; _433-LPCLLPQEY_-441; _90-NPFLLHLSQ_-98; _394-NYGSSITEA_-402; _247-PLPISSMGI_-255; _220-VPPTVEQKT_-228; _410-YPPGFGEVL_-418) were interacted with most frequent MHC class II alleles, demonstrated higher population coverage and three of them (_216-FLFLVPPTV-224; _499-GVFVFVSWV_-507 and _410-YPPGFGEVL_-418) were shown to interact with both MHC-I and MHC-II alleles. Therefore they were proposed as T helper cells epitopes. The population coverage was 60.35% and 99.96% for MHC-I and MHC-II epitopes, respectively, and 100% for all T cells epitopes. Taken together 17 epitopes successfully proposed as vaccine candidate against noroviruse. In vivo and in vitro clinical trials studies are required to elucidate the effectiveness of these epitopes as vaccine.

Noroviruses, NCBI, IEDB, Insilico vaccine, B cells, T cells