Herpesviridae | A detailed note of Herpes viruses

Herpesviridae is a huge family of Deoxyribonucleic acid viruses that influence infection and many other diseases. Humans are also affected by this DNA Herpes viruses.

Naturally, vertebrates and invertebrates both groups of the same individuals that could interbreed and their off-springs also fertile were influenced by these creatures and large numbers of their variety were characterized. Aggrandize of a few species debated here. These family members are called herpes viruses.

These were pervasively found everywhere so far and widespread pathogenicity in humans and animals. These family members are called herpes viruses in other words. These names were derivative of a Greek language word whose meaning was creeping sense and it was justified these creatures were found everywhere even in the flares.

Herpes viruses were generally found varieties of viruses that set up a long-lasting inflammation perpetual in the individuals which got widely affected. There was a misconception about an individual who was highly resistant against any kind of virus also gave opposition to these bacteria but later realized vascular disease resulted due to infection of vessels.

Historical background of Herpes viruses

The first is herpes simplex second is herpes zoster. In the year of 1971, the committee on the taxonomy of viruses which was ICTV recognized herpes viruses as a large
Group of certain viruses that have more than 23 genera which were arranged in 4 groups of taxa. Herpes viruses can also cause latent or late infection.

A common structure shared by all herpes viruses. Relatively a large and dual stranded DNA which is to be linear. This DNA is complete and linear and codes for 100-200 genes which are enclosed by an icosahedra protein case called capsid which itself is made up of protein and the protein layer of the virus is called tegument. This protein contains both proteins of viruses and mRNA of virus History of Herpes viruses

In 1960, a veterinary scientist named Walter Playwright isolated a thing from wildebeest and their genus was established in 1971 by ICTV.
Their genus includes 23 genera within 4 groups.

In the second report of ICTV in the year of 1976, the genus was given a family status.
This family was Herpetoviridae. Because of confusion with reptile derived viruses their name was changed into Herpesviridae.

In 1979, Reports of ICTV the family herpesviridae gave three subfamilies.
Which are Alpha Herpesviridae, Beta Herpesviridae and Gamma Herpesviridae?
It was also divided into 5 genera which included 21 viruses.

In the year 2009, this family herpesviridae given the status of order Herpesvirales.
This order includes 3 subfamilies and 17 genera and these 17 genera contain 90 species.
Evolution
The three subfamilies of mammals which are alpha, beta
And gamma may have arisen some 180 to 220 million years ago

General characterization of Herpes viruses

In human herpes viruses allocated these remarkable biological possessions. Firstly, unrepeated encoded nucleotides arrangement synthesizes the genetic material of herpes viruses. Distinctive organization and incidental in genetic makeup made them reticence against the agent that attacks the virus. The second, unification, and gathering of herpes virus genetic material started in the nucleus. Capsid’s congregation was also in the nucleus.

Third, they reproduced from the cell in which it caused infections and this cell died after the new ones ruptured and released outside. Fourth, these damaged the tissues and caused long-lasting infections on tissues as the other viruses do.

Herpesviruses was were proved to be so resistive against the human antibodies which the human-produced against them. The reason for the most resistance in them was understood that they stayed in the body of humans for a long period so these modified themselves against these antibodies. For checking the resistivity of viruses many experiments were performed.

In most cases of herpes viruses were used as an experimenting model to determine the latency of viruses. Some of the basic characteristics that were authenticated are these. First of all, how most viruses are so resistive against antibodies so how these had maintained this? Secondly, the Importance of microRNA was established for biological organisms.

Thirdly, herpes virus contains their genetic material in form of microRNA that had some kind of genes contain genetic sequences for the production of a specific protein, and also contained interesting products which also encoded on the genetic material of herpes virus.

Later another modification was made in which it was justified that these viruses also have some factors HHV which was a latency-associated transcript that was responsible for resistance and this virus could stay a long period in the host body. For the resistivity in the host body, the micron is very important because it also depends on the length of RNA.

If somehow the LAT factor could be controlled the resistivity can be controlled. If this factor is suppressed there will be no resistance so antiviral could easily attack and antibodies can take over these viruses and kill them. Some organisms that cause infections in the host body are known as pathogens.

If these are more resistant they can cause long term infections in the older age and so it should be lethal for humans, So antibiotics drugs were made which can be used against the viruses which was much expensive and not a permanent cure. But herpes viruses genome viruses were used which may be used as a permanent treatment against the resistance of viruses.

The HHV factor which was responsible for resistance depends on the length of RNA so herpes viruses would be used.KSHV was also discovered and a lot of work was done on them. These viruses are the causative agent of AIDS. These viruses focused everyone because AIDS is the most spreading disease in humans and this virus was also found in the patient of AIDS.

Kaposi’s sarcoma viruses were discovered in AIDS patients so these were researched a lot in the recent past. Many more viruses were discovered and the discovery changes the assumption about the microorganisms. Some viruses that cause the carcinogens were also identified; they were named as viral oncogenes.

It would be easily understood by the creeping viruses if we compared it with other viruses. Herpes virus was the most widely found invertebrate organism. These attack on the organisms and do not show their causative effects in the immature persons and also to those which had an impaired immune system. These organisms carry on within the nucleus of the cell which passed through infection.

The infections that were produced by the Herpes virus simplexes were firstly cured with the help of chemicals, and this experiment leads them to victory. Later vaccination was introduced for many types of viruses and children were vaccinated and still vaccinating in recent times.

Lifecycle herpes viruses

Nuclear replication is the character of herpes viruses.
The viral genome was first transcribed into mRNA and then translated.
Infection is started when a particular particle from a virus contacts
With a cell. There is a specific receptor site on the cell surface.

Binding is done with the help of special glycoprotein molecules on the cell surface.
Then this virion is internalized and this allows the viral genome to migrate the host cell nucleus.
Within the host cell the transcriptions of mRNA and later translation of
Virgin takes place.
During infection, the host cell transcribed the lytic genes of the virion.
In other host cells, a small number of genes of viruses called latency-associated
Gradually gathered.

Instead in this manner, the virus remains in the cell.
Whereas primary infection is done through a called self-limited
Period of illness or clinical. Long term dormancy is free of symptoms.

The reactivation of the dormant virus has been seen in many other diseases,
Such as shingles and mulphs.there has been continued success of virus over host cells
From time to time until a point where they dominated the cells. Then they
Use the machines of the host for their own benefit and thus destroyed the host cell by
Means of lysis and bursting.

After activation, the transcriptions of this viral DNA changes from LAT to multiple lytic genomes. This leads to more replication and more virus production within the host cell.
Lytic infection caused the bursting of cell and cell death of the host cell.
Clinical lytic infection is done through nonspecific factors.
These nonspecific factors are low-grade fever often headache and malaise.
Some clinical symbols are swollen of lymph and reduced level of nature

Structural conformation of herpes viruses

When studying the structure of these viruses, they were closely related to the viroid. In some manner they had DNA that was double-stranded that was present at the center of the body. The positioning of deoxyribonucleic acid was unknown in the core.

The core was made up of protein which was for the protection of genetic material. Herpesvirus genetic material consisted of deoxyribonucleic acid and molecular weights which ranged between 80-150millions or maybe measuring the length of the genetic material which was counted almost in the range of 120-250 kilo bases, these were for the different types of viruses. The protein coat that surrounded the genetic material was found in many capsomers which also varied in numbers.

Capsid looks very hard due to the construction material closely buffing each other. This made it a more resistive and amorphic look. Around the capsid, an outer covering was observed in which composition was observed that was two-layer of lipids. This lipid layer source is considered the material that comes from the cell wall of the organisms in which they were living.

In transition with lipid, some other chemicals were also considered that play a vital role in pathogenicity. These types of structural modifications gave them a unique antigenic characteristic.
A fascinating feature of herpes virus DNA is its genomic sequence arrangement. For convenience, these viruses were divided into further six groups which were started from A and ended at F. Especial types of herpes viruses was with different shapes that caused infection in human categorized into group C, D, and E.These small divisions were made based on different types of arrangement of genes. In the genome of group c, it was observed that their terminal end made some kind of extra repetition, from which these were further divided into the domains.

As in other group D, their genomic sequence was observed in which sequence at the terminal end was in invert form to the inner genome. In the other types of groups, their genome was observed which was divided based on internal variation in the genome, and group E genetic material had the same types of inverted sequence but internal changes were observed.

Climatic effects on herpes viruses
These viruses were found almost everywhere in the world. In the high-temperature regions, these were found and even also in colder regions. Some of the herpes viruses spend their early life in regions that were tropical and later stages of life they migrated to temperate zones. During favorable conditions these were seen in living form, meaning they were showing life processes. But during unfavorable conditions, they were found as crystal in the form of a cyst.

Classifying herpes viruses
These are categorized into a different group for further detail studies and grouping made it possible to find similarities and differences present among them. And also every group evolved with a specific characteristic. Stability was being established if new viruses were discovered these were easy to classify into any of these groups.

Herpes viruses
These viruses included the herpes virus belonging to the alpha category. These had a short reproduction period. This reproduction cycle consisted of a few hours. Attacked the host organism and they exhibit unique features they divide more fastly into the host cells and at the end the host cell busted, these came out if condition suitable and found any host they would attack otherwise they would act like non-living by making cyst when they find some host they would attack the host and continue the cyclic process.

These mainly affect the nervous system and ganglia of the sensory nerves. The person’s nervous senses damage and sensation do not properly work.
B herpes viruses
These types include the beta herpes viruses which reproductive life cycle was much different from the other types of viruses. They spend more time in the body of the host. They make the cell of the host organism big and they resist in the cell and divide after a long time. Some kinds of these viruses attack the human secretary gland and influence infection in them. Their size increases so largely .These can also attack the kidney and cause infections in them.
C herpes viruses
The last category that includes the gamma types of herpes viruses these most widely depend on the host body. They attacked the organisms only in particular parts, not on the whole body. These viruses attack the lymphoid tissues and infect them.
The replicating process plays a role to make them latent

Herpesviruses were replicated by a process that was further classified into many sub-processes. We can describe the whole process in steps. In the first step, the virus infected the host cell. For infection, some kind of receptor that stimulated the viruses and viruses entered the target cells using their specific structures.

In the next step DNA which was protected by a protective coat, further, this coat was removed and genetic material came out of the virus. The next step was to import the DNA into the host cell. This DNA was transcript and encoded for a specific protein that regulates the whole process. As genes encoded for a specific protein, this stimulated the response in the host cell that maybe lasted for a few periods or maybe gave long-lasting effects.

Congregation of virus core and assemblage of capsid were taken place in the nucleus. The process took place in the nucleus where the copy of genetic material was made; later this copy was transported out of the nucleus in the cytoplasm. There was endoplasmic reticulum and the Golgi apparatus was present where further processing took place.

Enzymatic processes that were used to make protein for the viral membrane took place in the Golgi apparatus. When a virus became mature it was thrown outside of the membrane. These were in the form of vesicles located inside and outside of the host body. When the virus produced their off-springs these were released out of the host body in the form of large numbers.

Meanwhile, the host cell busted, this led to the death of the cell and the host would no longer survive. It was understood about the herpes viruses that a few viruses which could be replicated otherwise the viruses which could not undergo this process remained as an infracting agent, this only damaged the host cell and remained in them till the death of the host.
The quality of these viruses that could not be neglected is that these viruses attacked the host and caused long-lasting latency in them, after that their genetic material may remain in isolated form or may be linked with the host genetic material. About the specificity of these viruses was described in this way every virus was specific for its type of host.

It only attacked the host which had specific receptors on the cell membrane and provided a strong signal for attachment. Different types of viruses were studied which caused latency only at a particular place and that place was only the root of ganglia.

Another type was studied that targets the cell of the lymphocytes and glands that secrete saliva. Other viruses had also specific sites where these could only attack and were specific only for that particular site.
Activation of these viruses was studied in which it was concluded that the replicating process was not limited to a specific time; it was activated at any time. This was a biological process in which the generation of viruses was increased. This process began with the specific signal that resulted in a specific starting codon initiating the replication process.

This was controlled by an early gene that name was Alpha gene which was present when viruses attacked the host and controlled the biosynthetic machinery of the host. But in later stages it remains silent but when the replication signal was achieved it started the process of replication.

Some factors were checked which affects the activity of replication. These factors were radiation, exposure to sunlight, and genetic factors that exploited different effects on the replication which was still being studied.

Signs of infections of Herpes viruses
When this virus was studied it was seen that these remained in the body for a long time but it didn’t show specific symptoms in the body. Most of the people that were infected never showed any of the specific signs of infection in the early stages. But as time passed every herpes-viruses showed the symptom according to their types.

Most of the cases ulcers or blisters were seen on the vaginal wall, the high temperature was also seen, red-blisters were on the skin and there was pain in the body. These viruses as seen were specific with the position on the sites. Many different types of a sign being shown by the human.

Treatments of infections
There was no specific drug that could be used against these viruses, but maybe some antiviral medicines were also used which prevented humans from herpes virus.
Conclusions
These viruses infected the host cell by which genetic material was transferred so that the pathogenicity was caused in the host cell. When DNA was transferred to the host. A specific protein was made that initiated the replication process, when the replication was taking place the host cell was destroyed.

When the host cell was destroyed, the off-springs came outside of the cell and looked for the new host if the host was not found. In this condition the genetic material was conserved. When the signal was received from the specific host that had receptors on the cell membrane they were penetrated in the host cell.

They were taken in the form of vesicles and caused latency in the host. Every herpes virus was specific to host, some cause severe infection on the different sites of the body so these were classified based on their host.

It was understood that if we controlled the factor that initiates the replication process would also control the pathogenicity of the herpes viruses, so preventive measures could be made possible but this was not permanent.

 

Leave a Comment