Figure 1: ApoE facilitates activation of CD1 restricted NKT cells. Inactivated NKT cells express surface marker of NK1.1 and an invariant TCR. ApoE facilitates lipid antigen presentation by CD1 positive APCs mainly through binding to LDLR. And then CD1 molecules present lipid antigen to NKT cells. Upon TCR ligation, naive NKT cells respond rapidly to secrete high levels of IFN-γ and IL-4.