Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico.
Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico.
Molecules. 2022 Feb 21;27(4):1451. doi: 10.3390/molecules27041451.
Dendritic cells are antigen-presenting cells, which identify and process pathogens to subsequently activate specific T lymphocytes. To regulate the immune responses, DCs have to mature by the recognition of TLR ligands, TNFα or IFNγ. These ligands have been used as adjuvants to activate DCs in situ or in vitro, with toxic effects. It has been shown that some molecules affect the immune system, e.g., Masticadienonic acid (MDA) and 3α-hydroxy masticadienoic acid (3α-OH MDA) triterpenes naturally occurring in several medicinal plants, since they activate the nitric oxide synthase in macrophages and induce T lymphocyte proliferation. The DCs maturation induced by MDA or 3a-OH MDA was determined by incubating these cells with MDA or 3α-OH MDA, and their phenotype was afterwards analyzed. The results showed that only 3α-OH MDA was able to induce DCs maturation. When mice with melanoma were inoculated with DCs/3α-OH MDA, a decreased tumor growth rate was observed along with an extended cell death area within tumors compared to mice treated with DCs incubated with MDA. In conclusion, it is proposed that 3α-OH MDA may be an immunostimulant molecule. Conversely, it is proposed that MDA may be a molecule with anti-inflammatory properties.
树突状细胞是抗原呈递细胞，可识别和处理病原体，随后激活特定的 T 淋巴细胞。为了调节免疫反应，树突状细胞必须通过识别 TLR 配体、TNFα 或 IFNγ 来成熟。这些配体已被用作佐剂，在体内或体外激活树突状细胞，但具有毒性作用。已经表明，一些分子会影响免疫系统，例如，存在于几种药用植物中的乳香酸（MDA）和 3α-羟基乳香酸（3α-OH MDA）三萜，因为它们激活巨噬细胞中的一氧化氮合酶并诱导 T 淋巴细胞增殖。通过用 MDA 或 3α-OH MDA 孵育这些细胞来确定 MDA 或 3α-OH MDA 诱导的树突状细胞成熟，然后分析其表型。结果表明，只有 3α-OH MDA 能够诱导树突状细胞成熟。当用 MDA 孵育的树突状细胞接种黑色素瘤小鼠时，与用 MDA 孵育的树突状细胞处理的小鼠相比，肿瘤生长速度降低，肿瘤内细胞死亡面积扩大。总之，提出 3α-OH MDA 可能是一种免疫刺激分子。相反，提出 MDA 可能是一种具有抗炎特性的分子。
