生物大分子红色诺卡氏菌细胞壁骨架增强 NK 细胞介导的肿瘤免疫治疗

The biological macromolecule Nocardia rubra cell-wall skeleton (Nr-CWS) has well-established immune-stimulating and anti-tumor activities.

However, the role of Nr-CWS on natural killer (NK) cells remains unclear.

Here, we explore the function and related mechanisms of Nr-CWS on NK cells. Using a tumor-bearing model, we show that Nr-CWS has slightly effect on solid tumor.

In addition, using a tumor metastasis model, we show that Nr-CWS suppresses the lung metastasis induced by B16F10 melanoma cells in mice, which indicates that Nr-CWS may up-regulate the function of NK cells.

Further investigation demonstrated that Nr-CWS can increase the expression of TRAIL and FasL on spleen NK cells from Nr-CWS treated B16F10 tumor metastasis mice. The spleen index and serum levels of TNF- , IFN- , and IL-2 in B16F10 tumor metastasis mice treated with Nr-CWS were significantly increased.

In vitro , the studies using purified or sorted NK cells revealed that Nr-CWS increases the expression of CD69, TRAIL, and FasL, decreases the expression of CD27, and enhances NK cell cytotoxicity. The intracellular expression of IFN- , TNF- , perforin (prf), granzyme-B (GrzB), and secreted TNF- , IFN- , IL-6 of the cultured NK cells were significantly increased after treatment with Nr-CWS.

Overall, the findings indicate that Nr-CWS could suppress the lung metastasis induced by B16F10 melanoma cells, which may be exerted through its effect on NK cells by promoting NK cell terminal differentiation (CD27 low CD11b high ), and up-regulating the production of cytokines and cytotoxic molecules.