Naïve cells are derived from stem cells, which are generated within the bone marrow. Naïve  T cells, or thymus cells, are stem cells that spend their maturation phase in the thymus and move into the lymphatic system.
Naïve  B cells, or bone marrow cells, mature in the bone marrow before they are released into the secondary lymphoid organs, including the lymph nodes, spleen, mucosal tissues, and lymphatic vessels.