Understanding the Herpes Virus at the Cell Level

The word "herpes" conjures up different images fordifferent herpesviruses and have found more than 50
different people. Some see herpes as an ugly anddifferent animal species that can be infected with
annoying cold sore or blister that periodically appearssome type of herpes virus. Humans appear to be a
on or around the lips. Others see herpes as a fearednatural reservoir for at least 8 different types of the
sexually transmitted disease that, once you haveherpes viruses that normally spread from human to
contracted, you have to suffer with for the rest ofhuman and generally do not cause disease in other
your life. Of course both of these images doanimals.Coming in contact with the virus, usually
represent the term "herpes" quite accurately forthrough sexual intercourse, is the first in a complex
many people throughout the world, but medicallyseries of events that result in contracting genital
speaking herpes is also appropriately applied toherpes. Projecting from the outer surface of the
several lesser known afflictions. These conditionsherpes virus are protein-carbohydrate structures
include herpes inside the mouth (herpescalled glycoproteins. Glycoproteins allow the virus to
gingivostomatitis), herpes of the throat (herpesattach initially to proteoglycans, which are complex
pharyngitis), herpes of the eye (herpes keratitis),chemical structures present on the surface of living
herpes of the brain (herpes encephalitis), herpescells. After attaching to the host cell, glycopoteins
transmitted to newborn infants (neonatal herpes),then interact with the cells surface structures to
chickenpox (varicella-zoster), mono (mononucleosis)trigger changes in the cell membranes cytoskeletal
and shingles (herpes-zoster). All of these conditionsstructure. These changes allow the viral envelope to
are caused by one of the two closely related herpesfuse with the cell plasma membrane, essentially
viruses known as herpes simplex virus type 1 andmerging to form a changed cell. When this fusion
herpes simplex virus type 2.To truly understand theoccurs, the nucleocapsid of the herpes virus enters
herpes virus it is helpful to first gain some knowledgeinto the cytoplasm of the host cell, attaching tiny
about viruses in general. Viruses are the smallestskeleton-like structures known as microtubules and
known microbes, or infectious agents, that medicalmicrofilaments which form an internal transportation
science has discovered to date. Most viruses consistnetwork used to move materials within the cell. Using
of a nucleic acid surrounded by a protein coat knownthis structure the DNA of the herpes virus enters the
as a capsid; this nucleic acid-protein complex isnucleus of the host cell where it makes copies of the
referred to as a nucleocapsid. In more complexviral DNA which are released from the cell and spread
viruses, such as the herpes virus, the nucleocapsid isto and infect other surrounding cells. This process of
surrounded by a membrane-like structure containinggenerating new virus particles kills the infected host
carbohydrates, lipids and proteins. This membrane-likecell.If the herpes virus remained in the skins cells
structure is referred to as an envelope. Each viruswhere initial viral attachment occurs, chances are that
contains one of two large complex chemicals thata healthy immune system could eventually control the
contain the viruses genetic code which serves as ainfection and rid the body of the virus. The herpes
blueprint for making more viruses. This complexvirus however has found a way to hide from the
chemical code is either RNA (ribonucleic acid) or DNAimmune system by hibernating in nerve cells. For
(deozyribonucleic acid).Unlike bacteria and moreunknown reasons the herpes virus does not start the
complex organisms, viruses do not carry all thereplicating process in a select number of nerve cells,
equipment necessary to reproduce themselves. Ininstead hibernating and establishing a latent infection.
order to multiply, a virus must enter a living cell,When the herpes virus is hybernating it is in an
remove the cells protein coat and then use its RNAinactive state and can not be detected by the
or DNA to redirect the cells synthesizing mechanismimmune system. This inactive state is referred to as
to make more copies of the virus. This process oflatent infection or simply latency. Latency does not
making new viruses can actually destroy or injure thecause illness but unfortunately the latent virus can
living or 'host' cell. If enough living host cells arereactivate and produce more virus which, in turn,
injured or destroyed it results in a viral illness such ascauses recurrent herpes.How reactivation occurs is
influenza (the flu), viral diarrhea or genital herpes.unknown but it can happen for no apparent reason
There are hundreds of known viruses and probablyor be triggered by trauma, stress, or exposure to
thousands of others not yet discovered. Each virusultraviolet radiation such as too much sunlight.
has adapted to infect a particular type of cell in aWhatever the trigger, after reactivation, the herpes
specific living organism which explains why there arevirus is transported from the nerve cell body to the
so many types of viruses. Because they havenerve endings where it is released into the skin to
become so specialized some viruses can only infectreplicate in the skin cells. This replication may
certain types of cells, for instance, liver cells orsometimes cause full blown herpes sores outbreaks,
muscle cells or brain cells while leaving other cellsbut other times may result in "shedding" the virus
alone. Likewise, many viruses are even limited to thewhich causes no recognizable symptoms. However,
type of species they can infect. In general, thiseither way, whether this reactivation is symptomatic
usually means that viruses which infect cells in oneor asyptomatic, the person is contagious during this
type of animal, say a dog, can not be passed on toreactivation period and it is possible to pass on the
another type of animal, say a cat. Of course as withvirus to a partner. For this reason, experts
most rules, there are exceptions and some virusesrecommend that people with genital herpes use
can cause similar diseases in closely related species.condoms even when there is no obvious symptoms
Another exception is that sometimes viruses canof an active herpes breakout.John Trout is an
cause also cause very different illnesses in the sameinternet research specialist and web master of
species.The term "herpesvirus" refers to any memberseveral information related websites including: where
of the herpes simplex type 1 and herpes simplexthis article was first published. This informative
type 2 virus family. The necleocapsid of a herpeswebsite is an excellent source for a sound education
virus is surrounded by an envelope with spike-likeabout the herpes virus as well as the latest news
structures projecting from the surface and containsabout treatments and a possible herpes cure.
DNA. So far, scientist have identified over 115