###### Abstract
These innate immune systems consist of (1) predatory and natural killer (NK) cells, (2) physical and chemical barriers by substances secreted by epithelial and epithelial surface barriers, (3) the complement system and other immune mediators, and (4) circulating plasma proteins, including cytokine proteins interleukin (IL)-1, 12, 15, etc., that regulate several activities of the cells involved in innate immunity [6]. The most numerous agonistic cells of innate immunity are bone marrow-derived cells that circulate in the blood and migrate to tissues. Microbial targets of innate immunity have characteristic molecular patterns (PAMPs) and pattern recognition receptors (PRRs) that recognize such structures [5; 6; 7]. Rice bran, a by-product of the rice dehulling process, is the brown layer between the outer husk of paddy and its kernel [8]. It contains dietary fiber, vitamins, minerals, fatty acids, and other sterols with known beneficial health effects [9]. The bran fraction of rice is composed of phytochemicals and nutrients with known cancer-fighting and immune-enhancing properties [10]. As an immunomodulator, rice bran has beneficial constituents such as polysaccharides, proteins, and oils [11]. Rice bran polysaccharide is one of the most studied bioactive compounds owing to its immunomodulatory activities, including augmenting macrophage phagocytosis, enhancing NK cell activity, regulating cytokine production, and acting as a natural adjuvant for dendritic cell (DC) activation [12; 13]. [PERSON] et al. [11] also reported the immunomodulatory ability of rice bran oil. In addition, it has been reported that rice bran extract MGN-3\({}^{\text{TM}}\) enhanced DC maturation [14], induced cytokine production, and increased NK cell activity by enhancing B-cell proliferation and inducing IL-2 and tumor necrosis factor (TNF)-\(\alpha\) production [15; 16]. Rice bran polysaccharides are bound to insoluble fibers, such as cellulose, hemicellulose, and lignin, \(\beta\)-glucan, and have low bioavailability [17]. Therefore, various studies have been focused on improving biological activity by modifying the structure of rice bran fibers using fermentation techniques [18,19]. It was reported that fermented rice bran with _Preussia anemulans_ enhanced immunomodulatory activity by increasing the polysaccharide content [20]. Dietary administration of rice bran fermented by _Lentinus eododes_ increased the activity of interferon (IFN)-\(\gamma\) in a randomized double-blind human clinical study [21]. Furthermore, it was reported that polysaccharides extracted from rice bran fermented with _Lentinus eododes_ enhanced NK cell activity and exhibited anticancer effects [22]. In our previous study, the fermentation process was improved to optimize the solubility of polysaccharides such as \(\beta\)-glucan, which are reported to have high immunomodulatory-latory functions [22,23], and the fermented rice bran extract (FRB) was prepared by performing process standardization using water-soluble \(\beta\)-glucan (M.W. \(<\) 2000) [24], which has high solubility and stability, as a biomarker. Preliminary studies suggest that FRB increases cytokine production and the function of Toll-like receptor-4 (TLR4) in a murine monocyte/macrophage cell line (RAW264.7) (in preparation for submission). Thus, the aims of this study are (1) to examine the immune response of lymphoid cells made by B cells, T cells, and NK cells by the administration of FRB and RB in in vitro and mice models, and (2) to investigate the change in the expression level of cytokines IL-1, IL-2, IL-12 (p70), INF-\(\gamma\), and TNF-\(\alpha\), etc., which are secreted from T helper type 1 (T\({}_{\rm H}\)1) by T cell activation [25], and to measure the effect on the secretion of IL-4 and IL-6, which are cytokines secreted from T\({}_{\rm H}\)2 with a cell-mediated immune response.