the common cold

Another repost from my old website. Hooray!

rossmann.virus.jpegOver the weekend I developed a curious sort of cough. It marked the beginning of my adventure through the common cold. It’s now Thursday and I’m pretty sure I’m on the mend.

It’s most likely that I’m suffering from a viral infection by a type of rhinovirus; a nose-dwelling virus that is responsible for between 25% and 80% of common colds. It’s possible that it could be a coronavirus (10-20%), an adenovirus (~5%) or even some form of influenza (10-15%) [1].

Rhinoviruses (image left – thanks are single-stranded positive sense RNA viruses with an icosahedral capsid constructed from 12 pentameters. An icosahedral structure is one that is constructed a bit like a soccer ball – pentamer structures (5 linked protein monomer units constructed from the 4 viral proteins [2]) form the outside layer of the virus.

You can probably see from the picture that the outside of the virus is not smooth like a soccer ball at all. It has protruding elements that enable the virus to attach to cellular receptors. Rhinoviruses can be grouped into 3 major categories depending on which cellular receptor they attach to: “intercellular adhesion molecule-1 (ICAM-1), low-density lipoprotein (LDL) receptors, and sialoprotein cell receptor” [1].

Can you guess at why it’s called a Rhinovirus? Yup, it’s because it likes to live only in the nose. The virus can survive only at temperatures a little below normal body temperature, from 33’C to 35’C. It also cannot tolerate an acidic environment. This is why the virus infection remains localised to the region called the nasopharynx which is a cavity located behind the nose but above the level of the soft palate. It’s sort of upward a bit from the back of your throat.

Now both you and I know know more about rhinovirus-related common cold infections. Unfortunately my search for a cure led me only to speculations that some ‘mystery ingredient’ in chicken soup ‘might help’. I’m dubious.