Genetic studies have revealed a large number of genetic associations with MS. Despite this progress, the mechanisms underlying the contribution of the genetic variants to the onset of MS remain mostly unknown. A recent analysis of all the genome-wide association studies of MS identified a new susceptibility locus that is found close to a gene called CD6.
CD6 plays an important role in the maintenance of T cell activation and proliferation.
T cells are thought to be the main immune cell that orchestrates the damage in MS.
In this study the researchers examined the biologic effects of the risk-associated genetic variant in CD6.
They report that the MS susceptibility variant in CD6 is associated with decreased expression of the full-length version of CD6 in the two major types of T-cells called CD4(+) and CD8(+) T cells.
As a consequence of this, proliferation of T cells is diminished during long-term activation of CD4(+) T cells from subjects with the risk allele.
These findings indicate that the MS risk variant in the CD6 gene is associated with altered proliferation of T cells and demonstrates the possible influence of a disease-related variants on immune function.