Most potent stimulator of Naive T-cells -

Mature Dendritic cells Mature B-cells and T-cells before antigenic exposure are called naive-B and T cells respectively. Sequence of events in activation of naive T cells. o Immature dendritic cells in the epidermis are called langerhans cell. o These immature dendritic cells (langerhans cells) capture the antigen in the epidermis. o After capturing the antigen these cells secrete cytokines. o These cytokines cause loss of adhesiveness of langerhans cells. o Langerhans cells separate from each other and migrate into lymphatic vessels. o In lymphatic vessel, maturation of langerhans cells takes place. Then these mature langerhans dendritic cells reach to naive T cells in the lymph nodes and present antigen to these cells and activate them.