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 . 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 . 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 .
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.
What is The Symptom of HCoV-HKU1?
HCoV-HKU1 usually causes mild to moderate upper respiratory illness, such as colds. Symptoms mainly include runny nose, headache, cough, sore throat, fever, etc., sometimes cause pneumonia or bronchitis and other lower respiratory diseases, which are more common in patients with heart and lung diseases, people with low immunity, infants and the elderly. HCoV-HKUI has been previously reported to be associated with seizures and gastrointestinal disorders in children. Recent studies have shown that it may be the potential cause of the onset of acute wheezing in infants, and can induce the onset of asthma in infants with acute wheezing. Currently, there is not vaccine available.
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  .
CUSABIO provides many HCoV-HKU1 recombinant antigens from different as follows:
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