Immune system’s language discovered

In a recent study published in Science researchers were able to for the first time, compile a complete catalogue of the human body’s immune response to pathogens and vaccines.

In particular, they managed to catalogue all the T lymphocyte clones that respond to a particular aggressor and determined “their specificity and their functional properties”. These include their ability to produce inflammatory mediators, which are substances used to combat inflammation, or to migrate to different tissues.

This discovery serves as a ‘Rosetta Stone’ – a key for decoding – which can be used to decipher the ‘language’ of T lymphocytes. The team attributes their success to the development of new methods for DNA sequencing (called Next Generation Sequencing), which made the cataloguing possible.

T lymphocytes, or T cells, play a central role in the body’s defence against a range of pathogens and other aggressors, such as bacteria, viruses and other pathogens, as well as tumours. These cells are cloned by the immune system, and combined in sequences, each of which serves a unique purpose in fighting against pathogens.

Next Generation Sequencing has previously allowed us to identify millions of these unique sequences and gain a basic understanding of their purpose. However, we still had a minimal understanding of how these cells work together to defend us against a diverse series of aggressors. The sheer complexity of deciphering the ‘language’ of T cells made it practically impossible to understand how they ‘communicate’.

According to Federica Sallusto, one of the members of the experimental team, “Using this new approach we can rapidly decipher the language of T lymphocytes, that is, their identity, specificity and function, and we can do it for the thousands of clones that mediate the immune response against microbes and vaccines.”