Identification of relevant regions on structural and nonstructural proteins of Zika virus for vaccine and diagnostic test development: an in silico approach

Zika virus (ZIKV) is an arbovirus belonging to the Flaviviridae family and the genus Flavivirus. Infection with ZIKV causes a mild, self-limiting febrile illness called Zika fever. However, ZIKV infection has been recently associated with microcephaly and Guillain-Barré syndrome. Vaccines for the disease are a high priority of World Health Organization. Several studies are currently being conducted to develop a vaccine against ZIKV, but until now there is no licensed ZIKV vaccine. This study used a novel immunoinformatics approach to identify potential T-cell immunogenic epitopes present in the structural and nonstructural proteins of ZIKV. Fourteen T-cell candidate epitopes were identified on ZIKV structural and nonstructural proteins: pr ³⁶⁻⁵⁰ ; C ⁶¹⁻⁷⁵ ; C ^103−117 ; E ^374−382 ; E ^477−491 ; NS2a ⁹⁰⁻¹⁰⁴ ; NS2a ^174−188 ; NS2a ^179−193 ; NS2a ^190−204 ; NS2a ^195−209 ; NS2a ^200−214 ; NS3 ^175−189 ; and NS4a ⁸²⁻⁹⁶ ; NS4a ⁹⁹⁻¹¹³ . Among these epitopes, only E ^374−382 is a human leukocyte antigen (HLA) type I restricted epitope. All identified epitopes showed a low similarity with other important flaviviruses but had a high conservation rate among the ZIKV strains and a high population coverage rate. Therefore, these predicted T-cell epitopes are potential candidates targets for development of vaccines to prevent ZIKV infection.