NIH investigators find link between DNA damage and immune response
Researchers offer the first evidence that DNA damage can lead to the regulation of inflammatory responses, the body's reaction to injury. The proteins involved in the regulation help protect the body from infection.
Akinso: Researchers have found a link between DNA damage and the way the body reacts to injury.
Resnick: We know that there are a set of genes, a set of proteins that are part of what is called the innate immune system.
Akinso: Dr. Michael Resnick is the principal investigator in the Laboratory of Molecular Genetics at the National Institute of Environmental Health Sciences and author of a recent study.
Resnick: The innate immune system deals with a set of standard kinds of threats to the body and it can be bacteria, it could be viruses, it could be different kinds of fungi and so on. Now when they come into the body they represent a threat, and the innate immune system has host in humans of 10 proteins called toll-receptors.
Akinso: Toll-like receptors are proteins that play a role in the immune system by defending the body from infection. Research suggests that an injury to chromosomes changes the way toll-like receptors work. Following damage, the toll-like receptors interact with a tumor suppressor gene to regulate the amount of inflammation. Dr. Resnick explains that the tumor suppressor gene P53 helps prevent threats to the human body that can lead to cancer.
Resnick: And the way it does it, it recognizes signals in chromosomes. And it directs a set of genes to either tell cells to stop growing until they repair, tell some cells that too much damage to die.
Akinso: Healthy volunteers with informed consent donated their blood cells for the study. The scientists separated white blood cells from the samples and exposed the cells to anti-cancer agents to activate p53. They then examined toll-like receptor genes. Researchers found that p53 generally led to the activation of several toll-like-receptor genes in patientsí cells. Again Dr. Resnick.
Resnick: And what we established is that the P53 system that deals with chromosome damage and determines whether cells are going to grow or survive after DNA damage, what we find is that system that can register DNA damage can also control the innate immune system. And what we think is that may enhance the ability in some way to deal with infections or bacterial infections or viral infections.
Akinso: Dr. Resnick says that humans evolved an inflammatory response when subjected to DNA damage. He adds that the variation in toll-like-receptor activity among humans suggests that some people are more prone to inflammation following DNA damage, for example, after receiving cancer therapy. For more information on this study, visit www.niehs.nih.gov. This is Wally Akinso at the National Institutes of Health Bethesda, Maryland.
About This Audio Report
Reporter: Wally Akinso
Sound Bite: Dr. Michael Resnick
Topic: DNA Damage, Immune System, Cancer
Additional Info: NIH investigators find link between DNA damage and immune response