Identification of Genetic Determinants of Emerging Tilapia Lake Virus (TiLV) and Development of Preventive Tool

Project: Research

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Tilapia is one of the fast-growing principally fresh and blackish water fish living in habitats such as lakes, ponds, and rivers. Because tilapia is known to be nutritious and contain essential protein sources, it has drawn increasing attention in aquaculture and the fish industry. Since early 2009, the large number of tilapia has sharply decreased, and the high morbidity rate seems to be caused by virus-like diseases, major gross pathology confined to the eye, brain, and liver; infected tilapia exhibit “syncytial hepatitis” findings. Using up-to-date comparative molecular differential diagnostic methods, the etiologic agent is identified as “Tilapia Lake Virus (TiLV)”, which is an orthomyxovirus-like virus. To date, TiLV cases have been reported in Africa, Asia and South America, and TiLV can pose a grave threat to the global tilapia industry and cause astronomical economic consequences due to the high mortality, which can severely harm fish farmers. TiLV is an emerging viral pathogen that is in the burgeoning stage of research. From the standpoint of the orthomyxovirus group, which includes public health inflicting influenza virus, ruling out the potential zoonotic inclination is a premature conclusion, even though no single human cases have been reported. Several groups have genetically characterized TiLV as a 10-segment negative-strand RNA virus, and among these segments, only one protein has a low-level homology with the PB1 gene of influenza C virus, but the other 9 segments have no detectable similarity with any other known sequences based on a nucleotide BLAST search and the GenBank database. However, from the genetic components of influenza C virus, we hypothesize that immunodominant Hemagglutinin Esterase Fusion (HEF) protein is incorporated in TiLV and efficiently expressed during the replication to play an important role in productive infection. To prove suggested central hypothesis, our research proposal aims to (i) genetically identify TiLV genome from positive samples (ii) transfer all ten subunits into well characterized alphavirus derived self-replicating replicon platform, respectively and package generated constructs with helper genome (iii) determine essential target proteins by biochemical and immunological assays in conjunction with newly synthesized antibodies and packaged particles. The replication-deficient replicon based approach can provide efficiency of live attenuated vaccine as well as safety of inactivated and subunit one and our long term goal is to create an efficient preventive tool against emerging TiLV to prevent its further spread and reduce economic losses in the aqua industry. 


Project number9048164
Grant typeECS
Effective start/end date1/01/2031/08/21