Most potent stimulator of naive Tcells?: (A) Mature dendritic cells, (B) Follicular dendritic cells, (C) Macrophages, (D) B cell
Answer is A. Ans. is 'a' i.e., 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 : . Immature dendritic cells in the epidermis are called langerhans cells. . These immature dendritic cells ( langerhans cells) capture the antigen in the epidermis. . After capturing the antigen, these cells secrete cytokines. . These cytokines cause loss of adhesiveness of langerhans cells. . Langerhans cells separate from each other and migrate to lymphatic vessels. . In lymphatic vessel, maturation of langerhans cells takes place. . Then these mature langerhan dendritic cells reach to naive T cells in the lymph nodes and present antigen to these cells and activate them.