Mapping the Human Immune System with Phage-Display Immunoprecipitation Sequencing

Researchers at the UMCG have mapped the human immune system for the first time. They did this by determining antibodies in the blood on a large scale in healthy people and people with chronic intestinal inflammation. The variation of antibodies in the body appears to be different for each person and provides information about their health.

By looking at the antibodies, researchers could see which disease someone had, such as chronic intestinal inflammation such as Crohn’s disease and who did not. To map the antibodies in the general population, the researchers used a new technology called phage-display immunoprecipitation sequencing (PhIP-Seq). This technique made it possible for the first time to study the antibodies in the blood on a very large and detailed scale.

Antibodies in the human immune system

Antibodies recognize possible pathogens from certain proteins on the cell and help to fight them. The body’s immune system makes these antibodies and can make new antibodies if you’ve had a certain infection or illness. These are then added to the ‘memory’ of your immune system to be able to recognize the same disease more quickly next time.

Antibodies can react to many different proteins: those that enter the human body via viruses, fungi, bacteria and food, as well as from the body’s own proteins. In this study, the researchers tested which proteins the participants’ antibodies reacted to. For this she used a large library of more than 300,000 proteins to which our immune system may respond. For example, they saw that the immune system of some people reacts to certain food components, so they may have a certain food allergy.

What do antibodies tell us about our health?

After analyzing the antibodies in the blood, the researchers found that some antibodies occurred in almost all people in the study, but also that certain antibodies only occurred in smaller groups of participants. Researchers use certain combinations of antibodies in the blood to see which disease someone has had and whether someone has an allergy. Sometimes antibodies also recognize human proteins as a possible disease maker, in which case an immune response arises against the body’s own. This can cause an autoimmune disease, such as rheumatism.

New knowledge about the immune system

According to the hospital, the research has now made an important wealth of new information available, allowing researchers to better understand infections, autoimmune diseases and allergies. In addition, antibodies in the blood provide insight into which bacteria in the gut (the microbiome) the immune system reacts to, both in healthy people and in people with chronic intestinal inflammations, and antibodies may also be used for diagnostics.

The study involved approximately 1,400 people participating in the Lifelines study and 500 people with chronic inflammatory bowel disease.