Don’t blame it all on genetics. Environment and your own healthy outlook still play a major role in keeping you free from disease. But researchers recently completed a study published in Nature Communications that puts a lot of responsibility for your immune health on your genetics.
The scientific community already knows that genes responsible for variation in our reactions to pathogens or inflammation are commonly targeted by natural selection. There are several studies showing association of genetic variation via SNPs or pathogen-mediated selection with autoimmune diseases, and others demonstrating that T cells are strongly influenced by genes.
Researchers at King’s College London performed a large analysis of 23,394 immune-associated phenotypes in 497 adult female twins. Based on the data they found that 76% of the traits showed predominantly genetic influence and 24% were mostly influenced by the environment. Twins are a very advantageous aspect of the study because they provide a high level of confidence in identifying heritable traits and also help to separate out common and shared environmental factors.
The group concentrated on collecting phenotypic traits that spanned the entire immune system, encompassing the representation and phenotype of all major lymphocyte and myeloid subsets in the peripheral blood. These cell types create a homeostasis within the body to protect us from outside threats and pathogens without activating abnormal responses that could lead to autoimmune issues.
One significant aspect of these results is that most of the traits involved in the adaptive immune system, the more complex part of the immune system that develops and retains responses to specific infections over time, are influenced by genetics. This is countered with the result that most of the genes in the innate immune system are influenced by environmental conditions, indicating the importance of our diet and overall health in shaping our innate immunity.
“Our genetic analysis resulted in some unusual findings, where adaptive immune responses, which are far more complex in nature, appear to be more influenced by variations in the genome than we had previously thought. In contrast, variation in innate responses, the simple nonspecific immune response, more often arose from environmental differences. This discovery could have a significant impact in treating a number of autoimmune diseases,” said Dr Massimo Mangino, lead researcher from King's College London.
The study highlights the potential use of personalized medicine for adaptive immune disorders. By understanding how genetics plays a role in influencing the adaptive immune system and exactly what genes are involved, clinicians can create individual and personalized treatments for specific disorders that move toward treating the disorder instead of masking general symptoms.
“Our results surprisingly showed how most immune responses are genetic, very personalized and finely tuned,” comments Professor Tim Spector, Director of the TwinsUK Registry, “What this means is that we are likely to respond in a very individualized way to an infection such as a virus - or an allergen such as a house dust mite causing asthma. This may have big implications for future personalized therapy.”
Sources: AAAS, Nature Communications