Genetic Immunity to HIV

Genetic Immunity to HIV

HIV has long been called the Modern Plague. It has spread from the first few cases discovered on the West Coast in the 1970’s to a worldwide pandemic that currently affects millions of people. However, there are people that, thanks to a rare form of a gene that codes for a certain receptor on cell surfaces, cannot easily acquire HIV. They can be regularly exposed to this deadly, resilient virus and come away unharmed. This is a major discovery that promises to completely change how HIV is treated in the years to come as our ability to influence the human body at the cellular level increases.

HIV causes its damage by destroying the body’s ability to fight off other infections. The virus is able to do this because it prefers to first invade and destroy the body’s T-Cells. It is the T-Cells that enable the body to mount a quick and effective defense against invading molecules. People do not die from HIV. People die from other, normally harmless, infections that take advantage of the body’s weakened state.

This paper written by Janet M. McNicholl and others describes the discovery of different forms of the gene CCR5. This is the gene that codes for a receptor on the surface of T-Cells. The normal form of this receptor is used as an entry point for the virus. If a person inherits a mutant form of this gene that is missing around thirty base pairs it codes for a receptor that will work normally in the body except that is just different enough form the normal value to inhibit the entry of HIV. If a person inherits a copy of this gene from both parents it is very hard for that person to get HIV though it is still possible. Even if a person was to inherit this mutation from only one parent he will still be resistant to the virus and will take an additional two years to develop full-blown AIDS.

This mutation is very rare. Only 1% of Caucasians have inherited the full mutant version of this trait. An additional 10 to 20% have inherited a single form of this trait. It is even rarer in non-Caucasians. It is found in 6% of African Americans, 7% of Hispanics, 13% of Native Americans, and 1% of Asians. This finding could help explain why different populations in the United States have different rates of new infections. Different groups could just be more venerable to HIV.

I thought that this article was interesting because this is the first time that I had heard that different genes could control the outcome of different diseases. It also means that there is new hope that scientists could one day develop a cure for HIV. If it is possible to alter the gene sequence that codes for this receptor or to block it altogether, then a vaccine could be developed. This discovery gives new hope to those who are living with a diagnosis of HIV positive.

Written By
A. Vogelgesang