Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires 1053, Argentina.
Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires 1053, Argentina.
Nutrients. 2022 Feb 8;14(3):723. doi: 10.3390/nu14030723.
Lipoteichoic acid (LTA) from Gram-positive bacteria exerts different immune effects depending on the bacterial source from which it is isolated. GG LTA (LGG-LTA) oral administration reduces UVB-induced immunosuppression and skin tumor development in mice. In the present work, we evaluate the immunomodulatory effect exerted by LGG-LTA in dendritic cells (DC) and T cells, both in vitro and in the gut-associated lymphoid tissue (GALT). During cell culture, LTA-stimulated BMDC increased CD86 and MHC-II expression and secreted low levels of pro and anti-inflammatory cytokines. Moreover, LTA-treated BMDC increased T cell priming capacity, promoting the secretion of IL-17A. On the other hand, in orally LTA-treated mice, a decrease in mature DC (lamina propria and Peyer's patches) was observed. Concomitantly, an increase in IL-12p35 and IFN-γ transcription was presented (lamina propria and Peyer's Patches). Finally, an increase in the number of CD103+ DC was observed in Peyer's patches. Together, our data demonstrate that LGG-LTA activates DC and T cells. Moreover, we show that a Th1-biased immune response is triggered in vivo after oral LTA administration. These effects justify the oral LTA activity previously observed.
革兰氏阳性菌的脂磷壁酸（LTA）因其来源不同，而对机体产生不同的免疫效应。经口给予 GG LTA（LGG-LTA）可减轻 UVB 诱导的免疫抑制和皮肤肿瘤的发生。本研究旨在评估 LGG-LTA 在树突状细胞（DC）和 T 细胞中的免疫调节作用，包括体外和肠道相关淋巴组织（GALT）内的作用。在细胞培养过程中，LTA 刺激 BMDC 增加 CD86 和 MHC-II 的表达，并分泌低水平的促炎和抗炎细胞因子。此外，LTA 处理的 BMDC 增强了 T 细胞的启动能力，促进了 IL-17A 的分泌。另一方面，在经口给予 LTA 的小鼠中，观察到成熟 DC（固有层和派尔集合淋巴结）数量减少。同时，固有层和派尔集合淋巴结中 IL-12p35 和 IFN-γ 的转录增加。最后，在派尔集合淋巴结中观察到 CD103+ DC 的数量增加。综上所述，本研究数据表明 LGG-LTA 可激活 DC 和 T 细胞。此外，我们还发现经口给予 LTA 后可在体内引发 Th1 偏向性免疫反应。这些作用解释了先前观察到的 LTA 的口服活性。
