Innate Lymphoid Cells Could Improve Function in the Ageing Brain

The brain has been traditionally viewed as an immune privileged organ – a site which is largely protected from immune system activity. Yet it is has become clear that the immune system does play a role in preserving brain function. Immune deficient mice have impaired cognitive function and are more succeptible to Alzheimer’s disease.

This study, published in the Journal of Experimental Medicine, has found that a particular type of immune cell, the group 2 innate lymphoid cell (ILC2), accumulates in the brains of ageing mice. However, these cells are functionally dormant. As ILC2s are involved in repairing damage in other tissues, researchers wanted to investigate whether reactivating the ILCs in the brain could improve cognitive function. Remarkably, this proved to be the case.

While this effect has so far only been observed in mice, the researchers also found that ILC2s accumulate in the brains of elderly humans. This finding is encouraging, as it suggests the possibility that similar benefits could be achieved with ILC2 activation in humans. Further work is planned to determine whether this is the case.