Dabie bandavirus
Classification
Orthornavirae; Negarnaviricota; Ellioviricetes; Bunyavirales; Phenuiviridae; Bandavirus
Species
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NCBI: [1] |
Bandavirus dabieense
Description and Significance
The Dabie bandavirus is a tick-borne virus. It was first identified in China and is primarily transmitted through the bite of a tick species that is commonly found in forested and rural areas. The virus’s lifecycle and spread are closely ties to tick populations, which thrive in humid environments. It is primarily found in East Asia, including China, Korea, and Japan, and has the potential to spread globally due to the migration of ticks. The virus can also inflect a range of animals, serving as reservoirs. The virus can be a significant public health threat due to its ability to cause Severe Fever with Thrombocytopenia Syndrome (SFTS), a potentially fatal disease with a mortality rate of 10% to 19%. While it is currently endemic is East Asia, the expansion of the tick habitats, increase the risk of the virus spreading to new regions. Recognizing the virus’s potential to cause outbreaks is essential for global preparedness, enabling regions to collaborate and implement strategies to decrease its impact.
Genome Structure
The bandavirus genus includes nine species, including the Dabie bandavirus which has a negative, segmented, single-stranded RNA genome (Kim et al., 2023). The genome of the bandavirus has five genes that encode for an RNA-dependent RNA polymerase (RdRp), a nucleocapsid protein (NP), a nonstructural protein (NSs), and two external glycoproteins (Gn and Gc) (Yu et al., 2011). There is a large (L), medium (M), and small (S) segment of the genome (Yu et al., 2011).
The L segment of the genome encodes for the RNA polymerase with 2084 residues of amino acids. It has an N-terminal endonuclease domain, polymerase core, and C-terminal cap-binding domain. Viral transcription is initiated in this segment when the RNA polymerase binds to the 5' cap of the host mRNA utilizing its cap-binding domain. This cuts the RNA and elongates it (Kim et al., 2023). Additionally, genome replication is initiated by the RNA polymerase, forming a viral RNA that is of full length using the complementary antigenomic RNA intermediate (Kim et al., 2023). Both the L and the M segments code using a negative sense coding strategy (Kim et al., 2023).
The M segment encodes a single open reading frame for the Gc and Gn glycoproteins precursors with 1073 amino acids (Yu et al., 2011). These proteins will bind to receptors in the cell in order for the virus to enter and penetrate the cell. When this happens, the Gc proteins are triggered to transport virions into endolysosomes with a pH ranging from 5.6-6 and will release the RNP complex composed with vRNA, RNA-dependent RNA, and N proteins (Kim et al., 2023).
The S segment has 1746 ambisense RNA nucleotides which encode for the NP and NSs proteins. There is a 54 nucleotide intergenic region between these, and they are oriented opposite of each other (Brennan et al., 2017). The N mRNA is transcribed from the viral sense, while NSs is from the antisense RNA intermediate (Kim et al., 2023). When the N protein associates with the RdRp, it will interact with the viral RNA and function as the RNA synthesis machinery. Translated Gn and Gc proteins are assembled by this RNP complex into the Golgi apparatus from which the infected virions will exit (Kim et al., 2023).
Cell Structure, Metabolism and Life Cycle
Dabie Bandavirus has a simple structure consisting only of nucleic acids encased in a protein coat and a lipid envelope. It is spherically shaped with a diameter of approximately 90-100nm (Liu et al., 2023). Its envelope is derived from the cell membrane of its host during the budding process, and it is a bilayer that holds the virus's glycoproteins that protrude from the surface. This envelope also protects the virus's components and is crucial for the virus's ability to infect a new host (Liu et al., 2023).
Dabie Bandavirus, like all other viruses, does not have the ability to generate energy on its own and, therefore, must utilize its host's metabolic resources. Dabie Bandavirus uses nonstructural proteins to facilitate energy acquisition and replication. These proteins interact with actin, an important component of the cytoskeleton in eukaryotic cells, which allows the virus to take over the host's machinery for its benefit (Liu et al., 2022).
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
References
https://www.ncbi.nlm.nih.gov/datasets/taxonomy/2748958/
https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0012411
Brennan, B., Rezelj, V.V., & Elliott, R.M. 2017. Mapping of Transcription Termination within the S Segment of SFTS Phlebovirus Facilitated Generation of NSs Deletant Viruses. Journal of Virology. 91(16). https://journals.asm.org/doi/10.1128/jvi.00743-17 [Accessed 10 November 2024]
Kim, E.H., & Park, S.J. 2023. Emerging Tick-Borne Dabie bandavirus: Virology, Epidemiology, and Prevention. Microorganisms. 11(9). https://pmc.ncbi.nlm.nih.gov/articles/PMC10536723/ [Accessed 10 November 2024]
Liu, B., Zhu, J., He, T., & Zhang, Z. 2023. Genetic variants of Dabie bandavirus: classification and biological/clinical implications. Virology Journal. 20(68). https://doi.org/10.1186/s12985-023-02033-y [Accessed 30 November]
Liu, H., Liu, S., Liu, Z., Gao, X., Xu, L., Huang, M., Su, Y., Wang, Z., & Wang, T. 2022. Dabie bandavirus Nonstructural Protein Interacts with Actin to Induce F-Actin Rearrangement and Inhibit Viral Adsorption and Entry. Journal of Virology. 96(14). https://doi.org/10.1128/jvi.00788-22 [Accessed 30 November 2024]
Yu, X.J., Liang, M.F., Zhang, S.Y., Liu, Y., Li, J.D., Sun, Y.L., Zhang, L. & Li, D.X. 2011. Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China. The New England Journal of Medicine. 364(16). https://www.nejm.org/doi/full/10.1056/NEJMoa1010095 [Accessed 10 November 2024]
Author
Page authored by Molly McMorrow, Gabriella Clark, Jayden Sturm, & Janey Metts, students of Prof. Bradley Tolar at UNC Wilmington.
