Śmiałek-Bartyzel Justyna, Bzowska Monika, Frączek Alicja, Wojda Iwona, Mężyk-Kopeć Renata, Bonarek Piotr, Blat Artur, Rak Jan, Mak Paweł
Doctoral School of Exact and Natural Sciences, Jagiellonian University, Łojasiewicza 11 Street, Kraków 30-348, Poland.
Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7 Street, Kraków 30-387, Poland.
ACS Infect Dis. 2025 Aug 8;11(8):2116-2130. doi: 10.1021/acsinfecdis.5c00066. Epub 2025 Jul 8.
This study describes the interactions between two different pro-inflammatory factors produced by bacteria, lipopolysaccharide (LPS) from Gram-negative bacteria and the peptide BacSp222 produced by a Gram-positive zoonotic strain, 222. We demonstrate that the mentioned molecules interact, forming a complex, and this phenomenon selectively reduces their biological activities in vitro and in vivo. Specifically, the levels of tumor necrosis factor (TNF) and nitric oxide (NO) produced by monocyte-macrophage cells were lower in samples treated with both LPS and BacSp222 compared to those treated with LPS alone. This is most likely because BacSp222 limited the ability of LPS to stimulate the TLR4 receptor. In the larvae injected simultaneously with LPS and BacSp222, the activity of hemolymph phenoloxidase, a key component of the insect immune response, was lower than that observed in larvae injected with either LPS or BacSp222 alone. Moreover, LPS inhibited the antibacterial activity of the bacteriocin, while BacSp222 limited LPS's ability to activate a proenzyme in the amebocyte lysate test. The changes in the activities of BacSp222 and LPS were attributed to the electrostatic interactions between LPS micelles and bacteriocin molecules, resulting in a decrease in LPS aggregate size and the direct formation of a complex between them, as revealed by gel filtration and isothermal microcalorimetry.
本研究描述了细菌产生的两种不同促炎因子之间的相互作用，即革兰氏阴性菌的脂多糖（LPS）和革兰氏阳性人畜共患病菌株222产生的肽BacSp222。我们证明上述分子相互作用形成复合物，并且这种现象在体外和体内选择性地降低了它们的生物活性。具体而言，与仅用LPS处理的样品相比，用LPS和BacSp222共同处理的样品中单核细胞 - 巨噬细胞产生的肿瘤坏死因子（TNF）和一氧化氮（NO）水平较低。这很可能是因为BacSp222限制了LPS刺激TLR4受体的能力。在同时注射LPS和BacSp222的幼虫中，昆虫免疫反应的关键成分血淋巴酚氧化酶的活性低于单独注射LPS或BacSp222的幼虫中观察到的活性。此外，LPS抑制了细菌素的抗菌活性，而BacSp222在变形细胞溶解物试验中限制了LPS激活一种酶原的能力。BacSp222和LPS活性的变化归因于LPS胶束与细菌素分子之间的静电相互作用，导致LPS聚集体尺寸减小以及它们之间直接形成复合物，这通过凝胶过滤和等温微量热法得以揭示。
