Natural Killer T (NKT) cells are a special subgroup of T cells that have both T cell receptor (TCR) and NK cell receptors on their cell surface.
Capable of expressing TCR like T cells, NKT cells can be specifically activated by the antigen-presenting cells (APC) which have CD1d molecules on their surface; consequently, a large number of factors such as IFNγ and IL-4 will be released in a short time. Characterized by rapid and efficient arousing of immune response, NKT cells play an important role in anti-tumor therapy.
Invariant natural killer T (iNKT) cells, a subgroup of NKT cells featuring a constant expression of TCRVα14, can also be activated by CD1d-containing APCs. With that small amount, generally 10 iNKTs per 10 million blood cells, this group of cells is a “special troop” of anti-tumor immune cells, fast in the immune response and efficient in killing tumor cells. iNKT cells not only kill tumors directly, but also activate other immune cells including NK and CTL cells to kill tumor cells together. Moreover, iNKT cells can kill tumor cells indiscriminately, therefore, iNKT cell therapy could be applied for various tumors, not even being limited by the MHC type.
Hrain is collaborating with experts from the University of California Los Angeles on iNKT cell therapy. The effectiveness of this therapy against tumors has now been demonstrated in mouse melanoma models, and relevant clinical trials are under preparation.