Research Advances of KRN7000 Analogues and Their Immune Activities

Abstract

KRN7000 has widely biological activities, such as anti-tumor, anti-tuberculosis, anti-fungal, anti-virus, anti-inflammation, and against auto-immune diseases. As the potential immunomodulator, KRN7000 can effectively activate the natural killer T cells (NKT cells) and induce the secretion of IFN-γ and IL-4 cytokines. However, IFN-γ inhibited the activity of T helper 2 cells (T H 2) and IL-4 inhibited the activity of T helper 1 cells (T H 1), which mediated humoral as well as celluar immune reactions, respectively. The concomitant of functions of T H 1 and T H 2 limits the therapeutic potential of KRN7000 against immune diseases. Therefore, developing new analogues of KRN7000 to find new immnostimulating drugs has drawn many attentions in the world. This review presents the recent progress in the study on the structure and immune activity of the synthesized KRN7000 derivatives. [6] 以及治 疗自身免疫性疾病(如系统性红斑狼疮 [7] 、糖尿病 [8] )等. 其中, 其高效的免疫调节活性最引人注目. 研究表明 KRN7000 可以通过活化自然杀伤 T 细胞(NKT)促进细 胞因子 IFN-γ 和 IL-4 的释放 [9] . KRN7000 可与 CD1d 蛋 白(CD1 蛋白质的一种, 可通过分泌脂质抗原活化 NKT 细胞)识别结合, 形成 CD1d/KRN7000 二元复合物, 进 而被 NKT 细胞表面的受体(TCR)识别, 形成具有免疫活 性的"CD1d 蛋白/KRN7000/NKT 细胞"三元复合物, 交互刺激 γ 干扰素(IFN-γ)及白介素 4 (IL-4)两大细胞因 子的释放 [10,11] . 这些细胞因子分别诱导 T 辅助细胞 1

A practical and scalable synthesis of KRN7000 using glycosyl iodide as the glycosyl donor

“…8 Therefore, a number of subsequent studies have focused on the ability to control the cascade by attempting to bias the Th1/Th2 cytokine release profile by employing KRN7000 as the template. 4,9,10 So far, many clinical studies on the development of a novel CD1d-binding NKT cell ligand as an additive vaccine adjuvant based on KRN7000 analogues are ongoing (Th1 cytokine bias). 11 Besides, KRN7000 analogues bearing functional groups are potentially versatile in conjugation strategies through facile reactions with a wide range of substrates to form highly defined synthetic vaccines, which has prompted intense interest in the context of "self-adjuvanting" vaccines.…”

Synthesis of Iminosugar‐Containing KRN7000 Analogues

“…[3,4] A large number of KRN7000 analogues and related compounds have been synthesized and their activity towards NKT cell-activation has been tested. [3][4][5][6][7][8][9][10] Modifications of KRN7000 are roughly based on three modifiable parts: sugar head moiety, ceramide part, and sugar-ceramide linkage. Sugar moiety modification studies suggested that: (1) α-glycosidic bond is essential for NKT cell-stimulation activity; (2) minor changes on sugar head can result in activity loss except that C-6 position can tolerate small substitutions.…”