A T cell (also known as a T lymphocyte) is a type of white blood cell that plays a central role in the adaptive immune response, responsible for recognizing and eliminating infected, cancerous, or foreign cells through cell-mediated immunity. T cells are classified into functionally distinct subsets — including cytotoxic T cells (CD8+), helper T cells (CD4+), regulatory T cells (Tregs), and memory T cells — each performing specialized roles in immune surveillance, immune regulation, and immunological memory. In cell therapy manufacturing, T cells are the primary starting material for CAR-T cell therapy, TCR-T cell therapy, and other adoptive cell therapy approaches, requiring specialized GMP manufacturing processes including apheresis, activation, viral vector transduction, expansion, cryopreservation, and release testing.
