Lycium barbarum Polysaccharide Promotes Maturation of Dendritic Cell via Notch Signaling and Strengthens Dendritic Cell Mediated T Lymphocyte Cytotoxicity on Colon Cancer Cell CT26-WT

Received Apr 6, 2017; Revised Sep 13, 2017; Accepted Sep 25, 2017

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1. Introduction

The concept of immune contexture is mainly emerged based on studies that are mostly performed with human colorectal cancer (CRC) [1]. Study of Pagès et al. showed that high density of intratumoral memory T cells was closely associated with the disease free time and overall survival rate of CRC patients [2]. In addition to the findings in CRC, Becht and his colleagues also proved the beneficial effect of high densities of T cells with a Th1 orientation and of cytotoxic $\mathrm{C}\mathrm{D}{\mathrm{8}}^{+}$ T cells in non-small cell lung cancer (NSCLC) [3, 4]. Therefore, harnessing the immune system of cancer patients (immunotherapy in oncology) has been proposed as promising therapeutic approach for treatment of types of cancers.

Generally, the immune system can prevent the development and progression of cancer through a mechanism called immune surveillance. However, once the process of immune surveillance fails due to variable causable factors [5], it will lead to the immune selection of tumor cell variants with reduced immunogenicity and allow progression of tumors [6, 7]. Currently, it is commonly recognized that functioning of an effective immunotherapy majorly depends on the roles of immune cells playing in the development of tumors, especially those with antigen presentation capability, that is, dendritic cells (DCs) [8], and those with cytolytic activity, that is, cytotoxicity T lymphocytes (CTLs) [9]. Thus, efficient induction of antitumor immunity via DC-based methods is emerging in recent decades [10–12]. However, induced maturation of DC by microbial products (such as LPS) or inflammatory cytokines (such as TNF) [13–15] is toxic and application limited. Therefore, exploration of nontoxic vehicles that are capable of inducing DC maturation and immunogenicity is imperative.

Lycium barbarum L. is a well-recognized East Asia herbal medicine used for treatment and prevention of disease such as insomnia, liver dysfunction, diabetes, visual degeneration, and cancer [16]. The bioactivity of Lycium barbarum L. is mainly attributed to its polysaccharide-protein complex [17–19]. The major component of Lycium barbarum polysaccharide (LBP) consists of six monosaccharides (galactose, glucose,...