Human Coronavirus HKU1
Human coronaviruses (HCoVs), which are enveloped RNA viruses belonging to the Coronaviridae family. HCoV infections occur mainly in the winter-spring season [1]. Thus far, seven types of HCoV have been discovered in humans: HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1, SARS-CoV, MERS-CoV and SARS-CoV-2 [2]. HCoV-HKU1, also known as human coronavirus HKU1, was first identified in Hong Kong in 2005. Infection by HCoV-HKU1 occurs worldwide and causes syndromes such as the common cold, bronchitis, and pneumonia [3].
What is HCoV-HKU1?
HCoV-HKU1 belongs to the A subgroup of the β coronavirus, with 29.9kb gene length and 32% GC content, which is the lowest among all known coronaviruses. The first 2/3 of the RNA strand encodes ORF1a /1b, and the last 1/3 encodes four structural proteins of HCoV-HKU1, including N, S, M, and E, as well as HE protein and auxiliary proteins (encoding regions ORF4 and ORF8) specific to β-coronavirus.
How does HCoV-HKU1 Enter The Human Cells?
Similar to other HCoVs, the spike (S) protein of HCoV-HKU1 plays an important role in the process of virus recognition and invasion into host cells. It has been reported that S protein will undergo structural changes before binding to cellular receptors, generating a fusion precursor, which provides support for the virus to bind to receptors and fuse with cell membranes. HCoV-HKU1I is the only human coronavirus with unknown cellular receptor to date. Studies have shown that 9-0-ethyl sialic acid is the receptor of HCoV-HKU1. The HE protein of HCoV-HKU1 is similar to the HCoV-OC43, which has the function of receptor hydrolase. After HCoV-HKU invades the body, the infection between adjacent cells may be an important reason for the virus to spread in vivo, and it is also one of the reasons for the virus to avoid the immune attack [4] [5].
CUSABIO provides many HCoV-HKU1 recombinant antigens from different as follows:
References
[1] Vabret, A, Dina, J, Gouarin, S et al. Human (non-severe acute respiratory syndrome) coronavirus infections in hospitalised children in France [J]. J. Paediatr. Child Health. 2008, 44, 176–181.
[2] Nehemya Friedman, Hadar Alter, Musa Hindiyeh et al. Human Coronavirus Infections in Israel: Epidemiology, Clinical Symptoms and Summer Seasonality of HCoV-HKU1 [J]. Viruses. 2018, 10, 515.
[3] Zhao Q, Li S, Xue F et al. Structure of the main protease from a global infectious human coronavirus, HCoV-HKU1 [J]. J Virol. 2008, 82(17): 8647-55.
[4] Dominguez SR, TravantyEA, QianZ, et al. Human coronavirus HKU1 infection of primary human type II alveolar epithelial cells: cytopathic effects and innate immune response [J]. PLoS One. 2013, 8(7):e70129.
[5] Huang X, Dong W, Milewska A, et al. Human coronavirus HKU1 spike protein uses O-acetylated sialic acid as an attachment receptor determinant and employs hemagglutinin-esterase protein as a receptor-destroying enzyme[J]. J Virol. 2015, 89(4):7202-7213.
