Natural killer T (NKT) cells are a population of T cells that share some characteristics with natural killer (NK) cells, which can recognize glycolipids presented by CD1d molecules expressed on antigen-presenting cells through cell recognition pathway. Activated NKT cells modulate the activity of other cells including B and T cells, NK cells, granulocytes, and dendritic cells through secreting a vast array of cytokines and chemokines. NKT cells also play an important role in linking innate and adaptive immune responses. Studies have shown that NKT cells not only play an important role in anti-bacteria, but also in anti-virus and anti-parasite infection.