Figure 8. Model of mannose receptor and TLR4 signaling in nicotine-increased cross-presentation.
The up-regulation of MR and TLR4, which was achieved via PI3K-Akt-mTOR-p70S6 pathway, lead to the endosomal translocation of internalized antigens, and the endosomal recruitment of TAP via TLR4-MyD88-IRAK4 signal, respectively. Increased translocations of internalized antigens toward endosomes, together with the endosomal recruitment of TAP, facilitate α7 nAChR activation-increased cross-presentation and subsequent cross-priming.