What markers are typically found on mature, peripheral helper T cells?

Mature, peripheral helper T cells are characterized by the presence of specific surface markers that distinguish them from other T cell subsets. The most definitive marker for helper T cells is CD4, which is critical for their function in the immune response, particularly in aiding B cells and enhancing the activity of other immune cells.

In addition to CD4, helper T cells also express CD2 and CD3. CD2 is involved in T cell adhesion and activation, while CD3 is part of the T cell receptor complex and is essential for signal transduction upon T cell activation. The combination of these markers — CD2, CD3, and CD4 — accurately represents the phenotype of mature helper T cells, highlighting their role in orchestrating immune responses.

The other combinations listed do not accurately define the surface markers typical of mature, peripheral helper T cells. For instance, the presence of CD8 would suggest cytotoxic T cells rather than helper T cells. Therefore, the selection of CD2, CD3, and CD4 provides a clear and correct identification of helper T cells in the immune system.