Scientists say they have found evidence that suggests genetics play a role in immune response, affecting our ability to fight off disease. This is according to a study published in the journal Cell.

A team of international researchers involved in the SardiNIA Study of Aging, led by Franceso Cucca, director of the National Research Council's Institute of Genetic and Biomedical Research in Italy, analyzed around 8.2 million gene variants in blood samples taken from 1,629 Sardinians.

In order to explain the basis of their study, the researchers note that the immune system is made up of two lines of defense: the innate immune system and the adaptive immune system.

The innate immune system involves the body using skin, mucus and specific cells and molecules as barriers which trigger a prompt that prevents harmful germs (pathogens) from entering the body.

The adaptive immune system is involved in prompting the body to produce, store and transport cells and molecules in order to trigger specific responses to ward off pathogens.

The researchers say that the immune system has evolved to reject some pathogens and even some cancers, but they note that high levels of immune function can also make the body more susceptible to autoimmune diseases, occurring when the body uses its own immune system against itself by attacking healthy cells.

Since the number of adaptive immune system cells that attack harmful germs or healthy cells seems to be regulated by genetics, the team set out to see whether this particular immune response could be inherited.

Small, single letter variations in genes naturally occur throughout the DNA code, the researchers say, but they do not generally affect any specific trait. However, they add there are some occasions where a certain gene variant is more common in people who have a trait or disease.

Immunity is in the genes

From their analysis, the researchers discovered 89 independent gene variants over 53 sites that were linked to the genome associated with regulating the production of immune system cells.

The team discovered that variants in particular genes had significant effects on the levels of one or more specific types of immune system cells.

Furthermore, it was found that some of these genes are also involved in the risk of various autoimmune diseases, including ulcerative colitis, multiple sclerosis, rheumatoid arthritis and celiac disease.

David Schlessinger, chief of the Laboratory of Genetics at the National Institute of Aging (NIA) and study author, says:

"We know that certain diseases run in families. From this study, we wanted to know the extent to which relative immune resistance or susceptibility to disease is inherited in families.

If your mother is rarely sick, for example, does that mean you don't have to worry about the bug that's going around? Is immunity in the genes? According to our findings, the answer is yes, at least in part."

The researchers say that understanding the genes affecting the immune system and the risk for autoimmune disease could be the first step toward developing personalized therapies dependent upon an individual's needs.

However, they note that further research is needed in order to better understand the role of genetics in the "complex dynamics of the immune system."

Medical News Today recently reported on a study that suggested a group of immune cells could be assisting the spread of cancer in the body.