Forever herpes type 1 is sealed with a lifetime mark. HSV1 is carried by more than half of all adults in the United States where it hibernates in the peripheral nervous system and cannot be removed.
Some HSV1 carriers will never get more than a cold sore as a result of the virus. Others on the other hand may experience blindness or life-threatening encephalitis.
How Herpes Enters The Nerve System For The Rest Of One’s Life
There is mounting evidence that it plays a role in dementia. A new Northwestern Medicine study has identified the virus’s cunning technique for invading the nerve system paving the way for the creation of long-awaited vaccines for both HSV1 and its close relative HSV2.
HSV2 which is more usually spread through sexual contact can be conveyed from a mother to a newborn as neonatal herpes which manifests as sores all over the infant’s body during the birthing process. The majority of babies recover but in the most severe cases, it can cause brain damage or spread throughout the body resulting in death.
A new Northwestern Medicine study led by Smith’s lab has found a way to get there. Herpes kidnaps a protein from epithelial cells and converts it into a defector to assist it going into the peripheral nervous system according to the research. They’ve coined the term “assimilation” to describe the process. According to Smith, the discovery could have far-reaching ramifications for a variety of viruses including HIV and SARS-CoV-2.
Herpes goes on a ‘cross-country’ journey.
Imagine the cell as a train station. The centrosome is the hub that connects all of the tracks. Train engines are made up of two proteins: dynein and kinesin. One leads to the central point say downtown while the other leads away from it to the suburbs.
Traveling down nerves on the other hand is the equivalent of a cross-country trip. Herpes uses the dynein engine for this journey but it also ensures that the kinesin engines do not return it in the same direction.
However, the dynein engine can only get it to the hub. Herpes must also get to the nucleus. That’s when it reaches into its ‘pocket’ and extracts a kinesin engine it hijacked from mucosal epithelial cells and persuaded to join its team. That assimilated kinesin then transports it directly to the nucleus in an act of treason.
“This is the first discovery of any virus repurposing a cellular protein and using it to drive subsequent rounds of infection,” said first author Caitlin Pegg a graduate student in Smith’s lab. “We are excited to further uncover the molecular mechanisms that these viruses have evolved that make them arguably the most successful pathogens known to science,” Smith said.
Riding the barrier
“The virus needs to inject its genetic code into the nucleus so it can start making more herpes viruses,” Smith said. “It reprograms the cell to become a virus factory. The big question is how does it get to the nucleus of a neuron?”
Herpes employs protein engines called dynein and kinesin to move along train tracks called microtubules in the cell as do many viruses. Herpes employs a kinesin engine that it brings from other cells to ferry it to the nucleus of the neuron according to Smith’s team. To suit the virus’s aim that kinesin protein becomes a defector.
