Final answer:
T cells, including cytotoxic T lymphocytes and helper T lymphocytes, are involved in adaptive immunity. Cytotoxic T cells destroy virus-infected cells, while helper T cells stimulate B cells to secrete antibodies. The differentiation of T cell responses depends on cytokines secreted by cells of the innate immune system.
Step-by-step explanation:
The types of leukocytes that are involved in adaptive immunity are T cells. There are two major types of T cells: cytotoxic T lymphocytes (Tc) and helper T lymphocytes (TH). Tc cells are responsible for destroying virus-infected cells, while TH cells stimulate B cells to secrete antibodies. The differentiation of TH1 or TH2 immune response depends on the specific cytokines secreted by cells of the innate immune system.