Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 17 2 2022 05 28 Immunoinformatics Evaluation of a Fusion Protein Composed of Leishmania infantum LiHyV and Phlebotomus kandelakii Apyrase as a Vaccine Candidate against Visceral Leishmaniasis 145 158 Shima Fayaz 1. Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran 2. Department of Immunology, Pasteur Institute of Iran, Tehran, Iran Fariborz Bahrami Department of Immunology, Pasteur Institute of Iran, Tehran, Iran Pezhman Fard-Esfahani Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran Parviz Parvizi Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Golnaz Bahramali Department of AIDS and Bloodborne Diseases, Pasteur Institute of Iran, Tehran, Iran Soheila Ajdary Department of Immunology, Pasteur Institute of Iran, Tehran, Iran 2021 09 24 2021 12 25 Background: Visceral leishmaniasis (VL) is a lethal parasitic disease, transmitted by sand fly vectors. Immunomodulatory properties of sand fly saliva proteins and their protective effects against Leishmania infection in pre-exposed animals suggest that a combination of an antigenic salivary protein along with a Leishmania antigen can be considered for designing a vaccine against leishmaniasis Methods: Three different fusion forms of L. infantum hypothetical protein (LiHyV) in combination with Phlebotomus kandelakii salivary apyrase (PkanAp) were subjected to in-silico analyses. Major Histocompatibility Complex (MHC) class I and II epitopes in both humans and BALB/c mice were predicted. Antigenicity, immunogenicity, epitope conservancy, toxicity, and population coverage were also evaluated. Results: Highly antigenic promiscuous epitopes consisting of truncated LiHyV (10-285) and full-length PkanAp (21-329) were identified in human and was named Model 1. This model contained 25 MHC-I and 141 MHC-II antigenic peptides which among them, MPANSDIRI and AQSLFDFSGLALDSN were fully conserved. LALDSNATV, RCSSALVSI, ALVSINVPL, SAVESGALF of MHC-I epitopes, and 28 MHC-II binding epitopes showed 60% conservancy among various clades. A population coverage with a rate of >75% in the Iranian population and >70% in the whole world was also identified. Conclusion: Based on this in-silico approach, the predicted Model 1 could potentially be used as a vaccine candidate against VL. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3466 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3466/1207