Which cell marker is associated with both memory B and T cells?

The cell marker that is associated with both memory B and T cells is CD27. CD27 is a member of the tumor necrosis factor receptor superfamily and serves as a co-stimulatory molecule that plays a crucial role in the activation and differentiation of these lymphocytes.

In the context of memory T cells, CD27 expression is important for their survival and longevity, as it helps to maintain their ability to mount a rapid and effective immune response upon re-exposure to antigens. For memory B cells, CD27 is also a marker of mature B cells that have undergone somatic hypermutation and affinity maturation, indicating their role in the adaptive immune response.

This dual association makes CD27 a key marker for identifying both memory B cells and memory T cells, highlighting its significance in immunological memory and the efficacy of the adaptive immune response. The other markers mentioned are more specific to particular cell types or functions; for instance, CD3 is primarily associated with T cells, while CD4 is a marker for helper T cells, and CD45 is a common leukocyte marker related to all leukocytes but not specific to memory cells.