What are T Cells?

T cells, also known as T lymphocytes or thymocytes, are an essential type of white blood cell in the immune system.  The term T cell encompasses three types of cells, cytotoxic, helper, and regulatory T cells, each with a specific role in the immune response.  T cells fight infection with macrophages by attacking foreign particles, play a role in adaptive immunity, responding to allergens, and have the potential to target and eliminate cancer cells in the body.  Unlike macrophages, which can attack any invading cell or virus, a T cell must be first activated by a detecting a specific antigen. T cells produce cytokines in order to mediate inflation and regulate the immune response.  Cytokines and chemokines are essential in T cell communication, differentiation, and activation processes. 

T cells are isolated from donor peripheral blood or derived from induced pluripotent stem cells (iPSC). The generation of functional T cells from iPSCs allows for widening accessibility of cells for treatments, as well as the potential creation of off-the-shelf T cell therapies.  

T cells can be genetically engineered with chimeric antigen receptors (CAR) for use in promising adoptive cell therapy against a number of cancers, shifting the paradigm of cancer treatment.  CAR-T immunotherapy enlists and strengthens the immune system through the engineered T cells, which direct the immune response to specifically target tumor antigens.