What surface markers on high endothelial venules are responsible for homing to the lymph nodes?

High endothelial venules (HEVs) play a crucial role in the homing of lymphocytes to lymph nodes. They are specialized blood vessels in lymphoid tissues that facilitate the entry of circulating white blood cells. The surface markers that are specifically important for attracting lymphocytes to these HEVs are chemokines such as CCL19 and CCL21.

CCL19 and CCL21 are chemokines that bind to the CCR7 receptor present on naive T cells and some dendritic cells. This interaction is essential for guiding these immune cells to the lymph nodes, where they can initiate immune responses. The expression of CCL19 and CCL21 on HEVs provides the necessary signals for lymphocytes to migrate to lymph nodes, ensuring that they are in the right location to encounter antigens and participate in the immune response.

In contrast, the other options represent different surface markers or receptors unrelated to the specific chemokine-mediated process involved in the homing of lymphocytes to lymph nodes. ICAM-1 and VCAM-1 are adhesion molecules that assist in the adhesion of leukocytes to endothelial cells but do not provide the specific signaling necessary for homing like the chemokines do. CCR5 and CCR10 correspond to different receptor