4,4′-diaponeurosporene, a C(30) carotenoid, effectively activates dendritic cells via CD36 and NF-κB signaling in a ROS independent manner

Carotenoids could be divided into C(30) carotenoids and C(40) carotenoids. The immune functions of C(40) carotenoids had been extensively researched, while those of C(30) carotenoids still remain unclear. In this study, the immune functions of a biosynthetic C(30) carotenoid, 4,4′-diaponeurosporene (Dia), were identified on dendritic cells (DCs). DCs treated with 1 μM Dia for 24 h showed morphologic and phenotypic characteristics of mature state and had an increased production of IL-6, IL-10, IL-12p70 and TNFα, while β-carotene had a suppressive effect on DCs maturation. Moreover, Dia promoted antigen uptake of DCs in vitro and increased the quantity of antigen loaded DCs in mesenteric lymph nodes (MLN). Dia-treated DCs also had an enhanced ability to stimulate T cell proliferation and Th1 polarization. Further researches showed that Dia activated DCs via CD36 as well as ERK, JNK, and NF-κB signals in a reactive oxygen species (ROS) independent manner.