Researchers at the Babraham Institute have, for the first time, demonstrated that T cells, a type of white blood cell that plays a central role in the body's immune response, can be tailor-made.

Active T cells, developed in the thymus from a complex cocktail of biochemical signals and intracellular genetic changes, are akin to the body's security surveillance system, detecting and administering to viruses and infections.  As we age, the thymus shrinks, producing fewer T cells. This is a normal occurrence that has little effect on healthy bodies. However, in individuals with HIV/AIDS, chemo/radiotherapy and bone marrow transplants, the body's ability to replace T cells is severely compromised, leaving us with fewer, less diverse cells patrolling our immune system and putting us at greater risk of infection.

The international team of academic and industrial immunologists, have discovered that a group of signaling proteins, called Phosphoinositide 3-kinases (PI3KS), known to transmit signals from external receptors to the inside of the cell, have multiple  signalling functions involved in the creation of T-cells. One signalling molecule, called PI3K-p110g, carries signals from a receptor known as CXCR4, which then binds to the chemokine CXCL12 that is produced in the thymus. When isolated from the thymus, T cells could continue their developmental program if cultured in the presence of CXCL12, bringing scientists one step closer to the ideal of full T cell development without feeder cells.

Besides progressing invitro T cell development, this discovery could also be valuable in clinical settings, where uncontaminated T cells are needed for transplantation and regenerative medicine.