Research Progress on NK Cell Receptors and Their Signaling Pathways

Figure 5

Synergistic activation of coactivation receptors is Vav1-dependent; NK cells promote the cytotoxicity and the secretion of INF-γ by the synergistic effects of NKG2D and 2B4 and 2B4 and DNAM-1. After coactivation receptors engaged, synergistic signals are integrated at SLP76. The phosphorylation of SLP76 induced by 2B4 was Fyn-dependent, whereas the phosphorylation of SLP76 in Y128 induced by NKG2D or DNAM-1 was SYK-independent. In contrast, CD16 can phosphorylate both Y113 and Y128 of SLP76 and sufficient to induce NK cell action on itself. Phosphorylated SLP76 associates with Vav1, resulting in phosphorylation of PLCγ2 and ERK, which promotes degranulation and INF-γ secretion of NK cells.