The general belief of the time of Human immunodeficiency virus (HIV) crossing to humans is between 1884 and 1924, but it may have infected humans longer than is believed. In addition, a newly discovered gene, Arih2, could treat and control chronic infections like HIV, hepatitis, and tuberculosis.

Alferd Roca, an assistant professor at the University of Illinois, thinks that the disease may have crossed to humans much earlier in some isolated rural populations without anyone discovering it. It is believed that HIV originated from chimpanzees in central Africa that were infected with simian immunodeficiency virus (SIV), a retrovirus. Biaka, a human community that inhabits near the range of chimpanzee subspecies, is believed to be the source of the current HIV pandemic. Scientists think that HIV-1 Type M, accounting for 90% of human infections, overcame the species barrier to spread to humans. However, evidence shows that the spreading of HIV in human requires population density of a large city, like the West Central Africa during the colonial era. As there was limited medicine and vaccinations, people who were infected may have succumbed first. It led to the prevention of the spreading of the immunodeficiency virus.

Finding out the when and how HIV was spread may help us track its origins; finding out a solution instead, could help treat and control it.

A gene called Arih2, is responsible for the function of the immune system. It decides whether to switch on the immune response to an infection, like HIV, an infection that is renowned for switching off the immune system. The discovery may have an implication that HIV can be overwhelmed. Arih2 is essential to the immune system as it raises the alarm about the invasion of foreign objects in human body. It decides whether the immune response should be begun or switched off to avoid chronic inflammation or autoimmunity.

Although immune system fights against many infections, some organisms have evolved to evade or counteract it so that they can stay in the human body. They exhaust and paralyze the T cells, a type of white blood cell, to force the system to shut down. HIV, hepatitis B, and tuberculosis are the examples. The discovery of Arih2 should allow us to circumvent this mechanism and reinvigorate the immune response temporarily to fight against these organisms. The scientists are investigating the way to control Arih2 to overwhelm infections. It is believed that it takes years to transform the discovery to a drug that could be used in humans.

Medical News Today, 25 Dec 2012
Medical News Today, 27 Nov 2012