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Classification
Viruses; Riboviria; Orthornavirae; Negarnaviricota; Haploviricotina; Monjiviricetes; Mononegavirales; Paramyxoviridae; Orthoparamyxovirinae; Henipavirus; unclassified Henipavirus
Species
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NCBI: [1] |
Langya henipavirus
Description and Significance
Henipaviruses are 40-600 nm in length, pleomorphic meaning their shape can vary from simple circles to complex, nonsegmented and negative-sense RNA meaning it needs to be first translated by a host cells Messenger RNA in order to being viral protein synthesis. (Payne 2017)
Like other Henipaviruses, Langya Henipavirus is part of a genus of medically significant viruses such as Measles virus, Mumps virus, Human parainfluenza, Nipah virus and Hendra virus along with a slew of other viruses, all that have proven to be life threatening to human beings. (Donnelly et al 2021). Just as we have with the other viruses listed, we should be quick to study and learn as much as we can about this new emerging virus in order to prevent as much damage as possible.
Genome Structure
At the point and time of writing this,November 15th 2022, Langya henipavirus’s genome is unmapped and unknown. However, we have mapped and studied several other henipaviruses such as the well known Nipah henipavirus and Hendrah henipavirus. So to better understand Langya henipavirus I have included information about the genus.
The Genus henipavirus genome is mononegaviral, Circular and around 18.2 kb in size, containing six protein production genes. Being a virus, it contains only a RNA strand and no chromosomes. The Henipavirus genus must follow a “rule of six”. Meaning that its genome must be a multiple of 6, if a mutation or incomplete genome synthesis occurs that deviates from this rule then they will be unable to replicate properly. (Kolakofsky et al. 1998).
Another interesting feature is its means of protein synthesis. Hepinaviruses uses co-transcriptional mRNA editing during transcription of the phosphoprotein gene to generate multiple protein synthesizing mRNAs from a singular gene. (Lo et Al. 2009).
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces. Henipaviruses are roughly 40 to 600 nm in length are pleomorphic meaning their sizes vary from spherical to filamentous and posses an envelope that covers the nucleocapsid. The surface of these envelopes have projections of one or two different lengths creating either a “double fringed” appearance, example being the Hendra Virus, or a “single fringed” appearance such as the Nipah virus. ( Hyatt et. al)
There are two proteins located in this envelope, receptor binding G glycoprotein responsible for attachment to host cells and the fusion F glycoprotein that mediates membrane mergence. Past the envelope is the M matrix protein, which is responsible for the links and bridges between its nucleocapsid and envelope. Finally, past the shell of matrix proteins is the segmented, circular negative sense RNA strand used for reproduction.
As a virus, it relies on cell hosts for energy for reproduction and a successful life cycle.
The LayV virus undergoes a Lytic life cycle. First it enters a cell through its attachment protein, then endocytosis then uncoating. Once inside the cell the virus releases its viral genome, resulting in initiation of transcription and accumulation of viral mRNA transcripts. While this undergoing, the viral genome is also transcribed into a full length anti-genome utilized to produce even more copies of the viruses genome. The accumulated viral mRNA transcripts are then translated into viral proteins, leading to the assembly, encapsulation and viral release via cell lysis. The newly released viruses then search for new cell host to repeat the process again. (Jensen et al 2018)
Ecology and Pathogenesis
Langya Hepnipavirus was first found in north-eastern sections of China in the cities Shandong and Henan. (Lu 2022). Being a virus, LayV must parasitize its hosts to survive and reproduce, resulting in no meaningful contributions to its environment other than the roles fufilled as a pathogen.
Shrews have been determined to be the reservoir for this virus, with 27% out of 262 shrews tested showed detectable levels of LayV. Other animals that showed detectable levels but at much lower frequency include 5% out of 79 tested dogs and 2% out of 168 tested goats. (Murugesu 2022). Based on current research it likely spreads from animal to human through contact, although we are unsure if it is through contact of the shrew or some intermediate animal. There is no current evidence of human to human contact.(Shopnil et. al)
Symptoms of infection are as follows:
Broad symptoms recorded from infected patients include: Fever (54%), Fatigue (54%), Coughing(50%), Muscle aches/pains(46%), nauseousness(38%), headaches(35%) and vomiting(35%). (Murugesu 2022)
Some extreme symptoms recorded include: Leukopenia(54%) which is characterized by an “insufficient number of pathogen fighting white blood cells”, thrombocytopenia(35%) characterized by a lack of platelets in the blood stream, impaired liver function (35%) and impaired kidney function (8%). Although some symptoms can be life threatening without treatment, no known cases of death from the virus have been reported. (Murugesu 2022)
References
Akash, S., Rahman, M.M., Islam, M.R. and Sharma, R. (2022), Emerging global concern of Langya henipavirus: Pathogenicity, virulence, genomic features, and future perspectives. J Med Virol. https://doi.org/10.1002/jmv.28127
Alex D. Hyatt, Sherif R. Zaki, Cynthia S. Goldsmith, Terry G. Wise, Sandra G. Hengstberger, Ultrastructure of Hendra virus and Nipah virus within cultured cells and host animals, Microbes and Infection, Volume 3, Issue 4, 2001, Pages 297-306, ISSN 1286-4579, https://doi.org/10.1016/S1286-4579(01)01383-1. (https://www.sciencedirect.com/science/article/pii/S1286457901013831)
Jensen KS, Adams R, Bennett RS, Bernbaum J, Jahrling PB, Holbrook MR (2018) Development of a novel real-time polymerase chain reaction assay for the quantitative detection of Nipah virus replicative viral RNA. PLoS ONE 13(6): e0199534. https://doi.org/10.1371/journal.pone.0199534
Murugesu, Jason Arunn (10 August 2022). "Langya virus: How serious is the new pathogen discovered in China?". New Scientist. Retrieved 15 November 2022.
Payne S. Introduction to RNA Viruses. Viruses. 2017:97–105. doi: 10.1016/B978-0-12-803109-4.00010-6. Epub 2017 Sep 1. PMCID: PMC7173417.
Kolakofsky D, Pelet T, Garcin D, Hausmann S, Curran J, Roux L. Paramyxovirus RNA synthesis and the requirement for hexamer genome length: the rule of six revisited. J Virol. 1998 Feb;72(2):891-9. doi: 10.1128/JVI.72.2.891-899.1998. PMID: 9444980; PMCID: PMC124558.
Lu, Donna (10 August 2022). "Newly identified Langya virus tracked after China reports dozens of cases". The Guardian.
Lo MK, Harcourt BH, Mungall BA, Tamin A, Peeples ME, Bellini WJ, Rota PA. Determination of the henipavirus phosphoprotein gene mRNA editing frequencies and detection of the C, V and W proteins of Nipah virus in virus-infected cells. J Gen Virol. 2009 Feb;90(Pt 2):398-404. doi: 10.1099/vir.0.007294-0. PMID: 19141449. thogen discovered in China?". New Scientist. Retrieved 15 November 2022.
Author
Page authored by Breeze Smith, student of Prof. Bradley Tolar at UNC Wilmington.
