Monday, February 13, 2012

The Structure Of Human Papilloma Virus

The human papillomavirus (HPV) is the virus responsible for genital warts. HPV can affect men or women, but the virus is a concern mostly for women. Certain strains of HPV can cause cervical cancer even though the woman shows no signs or symptoms. A vaccine was created to prevent the spread of HPV. Knowing the HPV structure and mode of infection helps people understand how the virus spreads and its function.


Non-Enveloped


A virus's outer layer is either enveloped or non-enveloped. The human papillomavirus is non-enveloped. Unlike bacteria viruses are more susceptible to drugs and the environment if they are enveloped. An envelope means the virus takes the outer membrane of a human cell when it leaves that cell. The outer membrane of a human cell is more susceptible to the environment and drugs, which makes the human papillomavirus less susceptible to prescription medication. Since the human papillomavirus is non-enveloped, it is more resistant to the environment.


DNA


Virus genomes are either in RNA or DNA. Unlike normal human or bacteria cells, a virus is able to strictly use RNA to make DNA. For instance, the HIV virus is an RNA virus. However, the human papillomavirus is a DNA virus so it makes its proteins directly from DNA. Another type of distinction in viruses is a single-strand or double-strand DNA molecule. Double-strand DNA (dsDNA) is generally in larger viruses.


L1 Protein


The L1 protein is responsible for the capsid of the virus. A capsid is the area of the virus that holds the RNA or DNA. The capsid defines the shape of the virus as well. The L1 protein that surrounds the DNA and makes up the capsid of the human papillomavirus is the focus of the HPV vaccine. The vaccine is used to elicit a response from the body to protect people from infection.


Diagnosis


HPV does not culture in a laboratory. Instead, when women go to their annual checkup, a pap smear is performed. The smear takes a sample of the cells in the cervix. These cells are then examined under the microscope. If any malformed cells show signs of abnormal growth the doctor asks the woman to come in for additional diagnostics.


Cancer


There are two proteins on the cells of the cervix that are responsible for cell growth regulation. The Rb and p53 proteins are responsible for the cell's death if it becomes diseased or the DNA is damaged. DNA from the virus creates proteins that attach to these regulatory proteins on the gene. This inhibits the cell's ability to die, so tumors are created from unregulated proliferation.







Tags: human papillomavirus, cells cervix, human cell, human papillomavirus non-enveloped, human papillomavirus virus