Education and outreach
Lisa A. Reynolds and B. Brett Finlay – both from the Michael Smith Laboratories at the University of British Columbia in Vancouver, Canada – explain in an article published in the journal Nature Reviews Immunology how the immune system reacts to foreign substances.
Our immune cells are always on the lookout for dangers, such as bacteria, viruses, parasites, and toxic substances. When these molecules enter the body – through the lungs, mouth, intestine, or skin – the immune system can react by labeling them as either harmless or dangerous.
Most of the time, our bodies accept or tolerate the presence of allergens.
This is called a Type 1 immune response, and the cell type at the heart of this process is the regulatory T cell.