With 10 million new cases and three million deaths estimated to occur yearly ̶ more than any time in history ̶ tuberculosis (TB) remains the single most widespread and deadly infectious disease. Until recently, it was thought that both latent and active TB was primarily related to host factors. Nonetheless, the participation of bacterial factors is becoming increasingly evident. Minimal variations in genes related to Mycobacterium tuberculosis (Mtb) virulence and pathogenesis can lead to marked differences in immunogenicity. Dendritic cells (DC) are professional antigen presenting cells whose maturation can vary depending on the cell wall composition of each particular Mtb strain being critical for the onset of the immune response against Mtb. Here we evaluated the role played by α-glucan, in the endogenous production of reactive oxygen species, ROS, and the impact on DC maturation and function. Results showed that α-glucans on Mtb induce ROS production leading to DC maturation and lymphocyte proliferation. Even more, α-glucans induced Syk activation but were not essential in non-opsonized phagocytosis. In summary, α-glucans of Mtb participates in ROS production and the subsequent DC maturation and antigen presentation, suggesting a relevant role of α-glucans for the onset of the protective immune response against TB.

据估计，每年有1000万新病例和300万人死亡，比历史上任何时候都要多。结核病（TB）仍然是最广泛，最致命的传染病。直到最近，人们还认为潜伏性结核病和活动性结核病都主要与宿主因素有关。然而，细菌因素的参与变得越来越明显。与结核分枝杆菌（Mtb）毒力和致病性有关的基因中的最小差异可导致免疫原性的显着差异。树突状细胞（DC）是专业的抗原呈递细胞，其成熟度会根据每个特定Mtb菌株的细胞壁组成而变化，这对于抵抗Mtb的免疫反应至关重要。在这里，我们评估了α-葡聚糖在活性氧，ROS的内源性产生中的作用，以及对DC成熟和功能的影响。结果表明，Mtb上的α-葡聚糖可诱导ROS生成，从而导致DC成熟和淋巴细胞增殖。甚至更多，α-葡聚糖可诱导Syk活化，但在非调理吞噬作用中不是必需的。总之，Mtb的α-葡聚糖参与了ROS的产生以及随后的DC成熟和抗原呈递，这表明α-葡聚糖在针对TB的保护性免疫应答的发生中具有重要作用。