Friday, 21 July 2017

The Potential Role of Cows in Preventing HIV Infections

The HIV virus is a nasty entity that attacks the immune system and stops it from doing its job. The infection can be deadly. Fortunately, the disease can be controlled, provided patients have access to antiretroviral therapy and follow its protocol correctly. The therapy inhibits or slows the replication of the virus. The therapy isn’t available everywhere in the world, however. People are still dying from AIDS, the end stage of the infection. It would be wonderful to stop the disease before it starts. The impressive immune system of cows may enable us to create a vaccine and/or new treatments for the disorder.


The green particles are HIV virions, or individual virus particles.
The blue object is a white blood cell.
Public domain photo from the CDC

Effects of HIV


The HIV or Human Immunodeficiency Virus destroys cells called helper T cells or CD4 cells. The latter name arises from the fact that the cells have a protein called CD4 on their membrane. Helper T cells are essential for activating other cells that either directly or indirectly destroy invading viruses, bacteria, and fungi.

As the viral disease progresses, so many CD4 cells are destroyed in the patient that their body can no longer fight infections or the types of cancer that are caused by an infection. Eventually the immune system is in such a weakened condition that is person is said to have AIDS, or Acquired Immunodeficiency Syndrome.

The HIV virus is transmitted by the transfer of specific body fluids from an infected person to an uninfected one. The CDC article in the “References” section below has more information about transmission.

The Controlled and the Uncontrolled Virus


For people who have access to proper therapy, an HIV infection is no longer an automatic death sentence. The therapy must be followed carefully and consistently, however.
"Today, someone diagnosed with HIV and treated before the disease is far advanced can live nearly as long as someone who does not have HIV." Quote from the CDC, or the Centers for Disease Control and Prevention

HIV is a horrible virus if it's not controlled, not only because of its dangerous effects but also because the active virus is so hard for the body to fight. The virus often mutates (changes genetically), even while it’s inside a patient's body. The mutation gives the virus new characteristics. This makes it difficult for the patient to create effective antibodies. Antibodies are proteins that attack harmful viruses and bacteria.

A very small number of patients manage to create antibodies that attack parts of the virus that are unaffected by mutations. This is the case even if the patients don’t receive antiviral therapy. The antibodies that they create are said to be “broadly neutralizing” because they attack many different versions, or strains, of HIV.

Cow Antibodies


Researchers have discovered that cows—or at least four of them—also make broadly neutralizing antibodies to the HIV virus. In addition, some of these antibodies appear and work in weeks instead of the years required in the human body. Specifically, the researchers found that after the cows were exposed to proteins from the HIV virus, the antibodies that they made were able to neutralize 26% of HIV strains within 42 days and 96% of them within 381 days.

"From the early days of the epidemic, we have recognized that HIV is very good at evading immunity, so exceptional immune systems that naturally produce broadly neutralizing antibodies to HIV are of great interest - whether they belong to humans or cattle." Quote from Dr. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases

Cows don't experience HIV infections in their normal lives. The researchers suspect that because the digestive tract of cows is exposed to so many bacteria in their diet, the animals have developed the ability to produce a wide variety of antibodies relatively rapidly. Their ability may help us to obtain new chemicals to fight the HIV virus in humans and perhaps to create a vaccine to prevent the infection.

References


HIV information from the CDC

HIV antibody production in cows