Scientists Uncover How MERS Coronavirus Attaches To Cells

Scientists have uncovered the structure of a key portion of the MERS coronavirus, revealing how it attaches itself to cells in the human body.

Asian Scientist (Jul. 8, 2013) – Chinese scientists have uncovered the structure of a key portion of the Middle East respiratory syndrome coronavirus (MERS-CoV), revealing how it attaches itself to, and thereby infect, cells in the human body. The discovery may pave the way for a vaccine against the deadly SARS-like virus.

Middle East respiratory syndrome (MERS) is viral respiratory illness first reported in Saudi Arabia in 2012. Most people infected with MERS-CoV developed severe acute respiratory illness and about half of those infected have died as a result of the illness.

The total number of confirmed MERS cases worldwide reached 80 this week, with the vast majority of cases in Saudi Arabia. The have been 44 deaths linked to MERS-CoV infection so far.

Although MERS-CoV and SARS-CoV (severe acute respiratory syndrome coronavirus) belong to the same coronavirus family, researchers have found that they attach themselves to different proteins, known as virus receptors, on the surface of human cells. After attachment to the cell surface, the virus is able to engineer its entry into the cell, thus resulting in an infection.

The MERS-CoV receptor was recently identified as CD26 (also known as DPP4), a protein found on the surface of most cell types.

Now, in a study published online in Nature, Chinese researchers have pinpointed the specific site on MERS-CoV through which the coronavirus particle attaches to the CD26 receptor.

By identifying this key site, known as the receptor-binding domain (RBD), the researchers were able to piece together a three-dimensional (3D) model of the MERS-CoV RBD and also visualize the structure of the RBD when attached to the CD26 protein.

The analysis provides insights into how MERS-CoV attaches to, and infects, human cells.

According to the scientists, it may be possible to develop a MERS-CoV vaccine through immunization with a protein fragment containing the MERS-CoV RBD. This is because the human body can generate antibodies that target the RBD, interfering with the attachment of MERS-CoV onto cells and thus protecting the body from infection.

The article can be found at: Lu et al. (2013) Molecular Basis Of Binding Between Novel Human Coronavirus MERS-CoV And Its Receptor CD26.

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Copyright: Asian Scientist Magazine. Image: NIH NIAID (NIAID_Flickr).
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Yew Chung is a postdoctoral research fellow at the Duke-NUS Graduate Medical School, Singapore.

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