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What type of specialized white blood cell interacts with other cells, regulating the production of antibodies and destruction of infected cells?

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Specialized white blood cells called B cells produce antibodies. Antibodies bind antigen and immobilize it, preventing it from causing infection. Antibody production is an adaptive immune response, specific against one antigen. B cells must interact with helper T cells, other specialized white blood cells, to initiate antibody production.

Antigens that escape antibody detection can enter and infect cells. The surface of infected cells changes, and this change is recognized by T cells. Cytotoxic T cells recognize and kill infected cells, preventing these cells from producing more antigen. Cytotoxic T cells must interact with helper T cells to initiate destruction of infected cells. Helper T cells regulate other cells of the immune system through secretion of molecules called cytokines ("-kine" relates to movement).

Phagocytes are white blood cells that engulf antigens. Phagocytosis is an innate, or nonspecific immune response.