Washington, August 19 (ANI): A new study has concluded that one key part of the immune system survived in the humans and other primates for almost 60 million years.
Researchers at the Oregon State University (OSU) and the Cedars-Sinai Medical Center in the US carried out the study.
They found out that one key part of the immune system, the ability of vitamin D to regulate anti-bactericidal proteins, is so important that is has been conserved through almost 60 million years of evolution and is shared only by primates, including humans - but no other known animal species.
The fact that this vitamin-D mediated immune response has been retained through millions of years of evolutionary selection, and is still found in species ranging from squirrel monkeys to baboons and humans, suggests that it must be critical to their survival, according to researchers.
Even though the "cathelicidin antimicrobial peptide" has several different biological activities in addition to killing pathogens, it's not clear which one, or combination of them, makes vitamin D so essential to its regulation.
The research also provides further evidence of the biological importance of adequate levels of vitamin D in humans and other primates, even as some studies and experts suggest that more than 50 percent of the children and adults in the US are deficient in "the sunshine vitamin."
"The existence and importance of this part of our immune response makes it clear that humans and other primates need to maintain sufficient levels of vitamin D," said Adrian Gombart, an associate professor of biochemistry and a principal investigator with the Linus Pauling Institute at Oregon State University.
In the new study, researchers from OSU and the Cedars-Sinai Medical Center describe the presence of a genetic element that's specific to primates and involved in the innate immune response.
They found it not only in humans and their more recent primate ancestors, such as chimpanzees, but also primates that split off on the evolutionary tree tens of millions of years ago, such as old world and new world primates.
The genetic material - called an Alu short interspersed element - is part of what used to be thought of as "junk DNA" and makes up more than 90 percent of the human genome.
In this case, the genetic element is believed to play a major role in the proper function of the "innate" immune system in primates - an ancient, first line of defense against bacteria, viruses and other pathogens. (ANI)